Background: Whether smoking is associated with worse quality of life (QoL) or not is relatively controversial. Current study is to investigate relationship between smoking and subjective QoL in a long cohort study.

Methods: NIPPON DATA 90 project collected 8383 community residents in 300 randomly selected areas as baseline data in 1990, and 4 follow-up QOL surveys and mortality statistics were performed. We conducted multinomial logistic regression analysis to compare past smoker and current smoker to never smoker, of which impaired QOL and mortality as outcomes.

Results: In 4 follow-ups, QOL data was collected from 2035, 2252, 2522 and 3280 participants, in 1995, 2000, 2005, 2012, respectively. In 1995 follow-up, current smoking at baseline was not associated with worse QOL. In 2000 and 2005 follow-up, smoking is significantly associated with worse QOL, OR = 2.11[95%CI: 1.33, 3.36, P<0.01], OR = 2.29[95%CI:1.38, 3.80, P < 0.001], respectively. In 2012 follow-up, smoking is not associated with QOL. Sensitivity analysis didn’t change the result significantly.

Conclusions: In this study we found that baseline smoking is associated worse QOL in long-follow-up.

Background: We evaluated the effectiveness of the BNT162b2 vaccine against infection, symptomatic infection, and hospitalization in older people during the Delta-predominant period (July 1 to September 30, 2021).

Methods: We performed a population-based cohort study in an older adult population aged ≥65 years using data from the Vaccine Effectiveness, Networking, and Universal Safety Study conducted from January 1, 2019, to September 30, 2021, in Japan. We matched BNT162b2 vaccinated and unvaccinated individuals in a 1:1 ratio on the date of vaccination of the vaccinated individual. We evaluated the effectiveness of the vaccine against infection, symptomatic infection, and COVID-19-related hospitalization by comparing the vaccinated and unvaccinated groups. We estimated the risk ratio and risk difference using the Kaplan–Meier method with inverse probability weighting. The vaccine effectiveness was calculated as (1 − risk ratio) × 100%.

Results: The study included 203,574 matched pairs aged ≥65 years. At 7 days after the second dose, the vaccine effectiveness (95% confidence interval) of BNT162b2 against infection, symptomatic infection, and hospitalization was 78.1% (65.2 to 87.8%), 79.1% (64.6 to 88.9%), and 93.5% (83.7 to 100%), respectively.

Conclusions: BNT162b2 was highly effective against infection, symptomatic infection, and hospitalization in Japan's older adult population aged ≥65 years during the Delta-predominant period.

Background: Per the biopsychosocial model, pain, especially chronic low back pain, which often presents with nonspecific pain, requires a comprehensive approach involving social factors. However, the association of social factors, including social isolation and loneliness, with this condition remains unclear. This study examined the cross-sectional association of social isolation and loneliness with chronic low back pain among older adults.

Methods: We recruited functionally independent older adults through a mail survey in 2019 from the Japan Gerontological Evaluation Study (JAGES). Chronic low back pain was defined as low back pain lasting more than three months. Social isolation was identified based on face-to-face and non-face-to-face interactions (“not isolated,” “isolated tendency,” and “isolated”). Loneliness was assessed using the UCLA Loneliness Scale (“not lonely,” “lonely tendency,” and “lonely”).

Results: Consequently, 21,463 participants were analyzed (mean age: 74.4 years; 51.5% females); 12.6% reported chronic low back pain. Multivariable Poisson regression analysis revealed that loneliness was significantly associated with the likelihood of chronic low back pain; compared with “not lonely”, the prevalence ratio (PR) was 1.14 (95% confidence interval [CI]: 1.05–1.25) for “lonely tendency” and 1.40 (1.27–1.54) for “lonely.” Social isolation was not associated; compared with “not isolated,” the PR (95% CI) was 0.96 (0.88–1.05) for “isolated tendency” and 0.99 (0.89–1.10) for “isolated.” A positive multiplicative interaction between social isolation and loneliness for chronic low back pain was found.

Conclusions: Lonelier individuals were more likely to experience chronic low back pain, and those with loneliness and social isolation were synergistically more likely for this condition.

Background: The association between the frequency of going outdoors and the risk of poor oral health has been reported in several studies; however, the findings have been inconclusive.

Methods: We conducted a 3-year longitudinal study of 19,972 Japanese adults aged ≥65 years who reported no poor oral condition at baseline in 2013. The respondents rated their frequency of going outdoors in three categories (≤1, 2–3, or ≥4 times/week), and the oral conditions reported in 2016 included tooth loss, chewing difficulty, swallowing difficulty, dry mouth, and composite outcomes. The associations between the frequency of going outdoors and the risk of poor oral health were examined as relative risk ratios (RRs) and 95% confidence intervals (CIs) using multivariable Poisson regression, while mediation analysis was performed to investigate indirect effects.

Results: During the follow-up, 32.5% of participants developed poor oral health. In the mediation analysis, indirect effects were observed through low instrumental activities of daily living, depressive symptoms, little social network diversity, and underweight. Compared to going outdoors ≥4 times/week, the multivariable RRs of composite poor oral health conditions were 1.12 (95% CI, 1.05–1.20) for 2–3 times/week and 1.22 (95% CI, 1.07–1.39) for ≤1 time/week (P-trend < 0.001). Similar associations were observed for tooth loss, chewing difficulty, and swallowing difficulty; the corresponding RRs were 1.07 (95% CI, 0.97–1.19) and 1.36 (95% CI, 1.13–1.64) (P-trend = 0.002), 1.18 (95% CI, 1.06–1.32) and 1.30 (95% CI, 1.05–1.60) (P-trend < 0.001), and 1.15 (95% CI, 1.01–1.31) and 1.38 (95% CI, 1.08–1.77) (P-trend = 0.002), respectively.

Conclusion: The frequency of going outdoors was inversely associated with the risk of poor oral health through several modifiable risk factors in the older population.

Background: Many epidemiological studies have investigated dietary intake of antioxidant vitamins in relation to prostate cancer risk in Western countries, but the results are inconsistent. However, few studies have reported this relationship in Asian countries.

Methods: We investigated the association between intake of vitamins, including lycopene, α-carotene, β-carotene, vitamin C, vitamin E, with prostate cancer risk in the Japan Public Health Center-based Prospective (JPHC) study. 40,720 men without history of cancer finished the food frequency questionnaire (FFQ) and were included in the study. Hazard ratios (HRs) and 95% confidence intervals (CIs) of prostate cancer risk were calculated according to the quintiles of energy-adjusted intake of vitamins using Cox models.

Results: After an average of 15.2 years (617,599 person-years in total) of follow-up, 1,386 cases of prostate cancer were identified, including 944 localized cases and 340 advanced cases. No associations were observed in consumption of antioxidant vitamins, including α-carotene, β-carotene, vitamin C, and vitamin E, and prostate cancer risk. Although higher lycopene intake was associated with increased risk of prostate cancer (highest vs lowest quintile, HR 1.24; 95% CI, 1.04–1.47; P for trend = 0.01), there was a null association of lycopene intake with risk of prostate cancer detected by subjective symptoms (HR 1.12; 95% CI, 0.79–1.58; P for trend = 0.11).

Conclusion: Our study suggested no association between antioxidant intake of vitamins and prostate cancer risk.

Background: Acute pulmonary embolism (PE) is a life-threatening in-hospital complication. Recently, several studies have reported the clinical characteristics of PE among Japanese patients using the diagnostic procedure combination (DPC)/per diem payment system database. However, the validity of PE identification algorithms for Japanese administrative data is not yet clear. The purpose of this study was to evaluate the validity of using DPC data to identify acute PE inpatients.

Methods: The reference standard was symptomatic/asymptomatic PE patients included in the COntemporary ManageMent AND outcomes in patients with Venous ThromboEmbolism (COMMAND VTE) registry, which is a cohort study of acute symptomatic venous thromboembolism (VTE) patients in Japan. The validation cohort included all patients discharged from the six hospitals included in both the registry and DPC database. The identification algorithms comprised diagnosis, anticoagulation therapy, thrombolysis therapy, and inferior vena cava filter placement. Each algorithm’s sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were estimated.

Results: A total of 43.4% of the validation cohort was female, with a mean age of 67.3 years. The diagnosis-based algorithm showed a sensitivity of 90.2% (222/246; 95% confidence interval [CI], 85.8–93.6%), a specificity of 99.8% (228,485/229,027; 95% CI, 99.7–99.8%), a PPV of 29.1% (222/764; 95% CI, 25.9–32.4%) and an NPV of 99.9% (228,485/229,509; 95% CI, 99.9–99.9%) for identifying symptomatic/asymptomatic PE. Additionally, 94.6% (159/168; 95% CI, 90.1–97.5%) of symptomatic PE patients were identified using the diagnosis-based algorithm.

Conclusion: The diagnosis-based algorithm may be a relatively sensitive method for identifying acute PE inpatients in the Japanese DPC database.

Background: Alcohol drinking behaviors change temporally and can lead to changes in related cancer risks; previous studies have been unable to identify the association between the two using a single-measurement approach. Thus, this study aimed to investigate the association of drinking trajectories with the cancer risk in Korean men.

Methods: A trajectory analysis using group-based trajectory modeling was performed on 2,839,332 men using data on alcohol drinking levels collected thrice during the Korean National Health Insurance Service’s general health screening program conducted between 2002 and 2007. Cox proportional hazards regression was performed to evaluate the associations between drinking trajectories and cancer incidence, after adjustments for age, income, body mass index, smoking status, physical activity, family history of cancer, and comorbidities.

Results: During 10.5 years of follow-up, 189,617 cancer cases were recorded. Six trajectories were determined: non-drinking, light, moderate, decreasing-heavy, increasing-heavy, and steady-heavy. Light-to-heavy alcohol consumption increased the risk for all cancers combined in a dose-dependent manner (adjusted hazard ratio [aHR] 1.03; 95% confidence interval [CI], 1.02–1.05 for light drinking, aHR 1.06; 95% CI 1.05–1.08 for moderate drinking, aHR 1.19; 95% CI, 1.16–1.22 for decreasing-heavy drinking, aHR 1.23; 95% CI, 1.20–1.26 for increasing-heavy drinking, and aHR 1.33; 95% CI, 1.29–1.38 for steady-heavy drinking [P-trend <0.001]). Light-to-heavy alcohol consumption was linked to lip, oral cavity, pharyngeal, esophageal, colorectal, laryngeal, stomach, and gallbladder and biliary tract cancer risks, while heavy alcohol consumption was associated with hepatic, pancreatic, and lung cancer risks. An inverse association was observed for thyroid cancer. The cancer risks were lower for decreasing-heavy drinkers, compared to steady-heavy drinkers.

Conclusion: No safe drinking limits were identified for cancer risks; reduction in heavy intake had protective effects.

Background: Disaster survivors experience deterioration in lifestyles and an increase in constipation. After the Great East Japan Earthquake in 2011, some survivors were evacuated for a long term, even after moving to temporary housing and public reconstruction housing. However, annual changes in constipation and the association between lifestyles and constipation among the survivors are still unknown.

Methods: Overall, 9,234 survivors aged 18 years or older participated in this 9-year follow-up survey after the disaster. Information about the prevalence of constipation and lifestyle factors (diet, physical activity, and mental health) was collected using a self-reported questionnaire. Their dietary intake was categorized into the following two dietary patterns: prudent (fish and shellfish, soybean products, vegetables, fruits, and dairy products) and meat (meat and eggs). Odds ratios for constipation according to lifestyle factors were calculated using a generalized linear mixed model.

Results: In women, the prevalence of constipation was the highest at baseline (8.7%) and remained around 5% afterward. In both men and women, older age, poor mental health, and poor physical activity were significantly associated with higher odds ratios of constipation. Moreover, a lower frequency of meals and a lower prudent dietary score were significantly associated with women’s constipation.

Conclusion: The prevalence of constipation was the highest at baseline and remained around 5% in women. Lifestyle factors, such as poor mental health, physical inactivity, and low frequency of meals were associated with constipation. Our findings suggest continuous support for the survivors with constipation for medium- to long-term after disasters.

Background: The COVID-19 pandemic may have reduced opportunities for engaging in physical activity (PA) and increased sedentary behavior (SB) among workers. However, most previous studies used self-reported assessments. This study aimed to examine the changes in accelerometer-measured PA and SB from before to after COVID-19 outbreak among Japanese workers.

Methods: This one-year longitudinal study used data from the annual health check-ups of workers who lived in the Tokyo metropolitan area. Baseline and follow-up data were collected from June to November, 2019 and June to November, 2020, respectively. Participants were asked to wear the accelerometer on their hip during awake hours for at least 10 days in both the surveys. Before the analysis, considering the difference in wearing time, time spent in PA and SB were converted to the percentage of wearing time. To investigate the changes in PA or SB from before to during COVID-19 outbreak, paired t-tests were performed.

Results: Of the 757 eligible participants, 536 were included in the analysis (70.8%). Participants’ mean age was 53.3 years; 69.6% were female; and most were full-time employees. Time spent in PA decreased, regardless of weekdays or weekends, although changes on the weekends were not significant. Conversely, time spent in SB increased on both weekdays and weekends in 2020. These changes corresponded to approximately 10 minutes per day increase/decrease in PA/SB.

Conclusion: Objectively measured PA decreased and SB increased by approximately 10 minutes per day after the COVID-19 outbreak among Japanese workers.

Background

Symptoms after COVID-19 recovery by SARS-CoV-2 strains are unspecified.

Methods

This self-administered questionnaire-based study was conducted to investigate symptoms after COVID-19 recovery at one of the main hospitals for COVID-19 treatment in Hiroshima, Japan, from September 2020 to March 2022 for patients who visited follow-up consultations after COVID-19. Study subjects were divided into four groups (Wild-type, Alpha, Delta, and Omicron periods) according to COVID-19 onset date. Hierarchical cluster analysis was performed to determine symptom clusters and investigate risk factors for each symptom cluster using multivariate analysis.

Results

Among 385 patients who enrolled in this study, 249 patients had any persistent symptoms at a median of 23.5 [IQR, 20-31] days after COVID-19 onset. Among patients with any persistent symptoms, symptom clusters including olfactory or taste disorders, respiratory symptoms, and cardiac symptoms were found. Respiratory symptoms were more frequent among patients infected in the Omicron period compared to the Wild-type period (AOR, 3.13; 95% CI, 1.31-7.48; p=0.0101). Compared to patients who recovered from mild COVID-19, patients who needed for oxygen or ventilation support suffered fewer post-COVID-19 respiratory symptoms (AOR, 0.46; 95% CI, 0.22-0.97; p=0.0415) but more post-COID-19 cardiac symptoms among them (AOR, 2.67; 95% CI, 1.26-5.65; p=0.0103). Olfactory or taste disorders were fewer among patients infected in the Omicron period compared to the Wild-type period (AOR, 0.14; 95% CI, 0.04-0.46; p=0.0011).

Conclusion

This study revealed that symptoms after COVID-19 may vary depending on the infected strain.

Background: Ambient particulate matter is classified as a human Class 1 carcinogen, and recent studies found a positive relationship between fine particulate matter (PM_2.5) and liver cancer. Nevertheless, little is known about which specific metal constituent contributes to the development of liver cancer.

Objective: To evaluate the association of long-term exposure to metal constituents in PM_2.5 with the risk of liver cancer using a Taiwanese cohort study.

Methods: A total of 13,511 Taiwanese participants were recruited from the REVEAL-HBV in 1991–1992. Participants’ long-term exposure to eight metal constituents (Ba, Cu, Mn, Sb, Zn, Pb, Ni, and Cd) in PM_2.5 was based on ambient measurement in 2002–2006 followed by a land-use regression model for spatial interpolation. We ascertained newly developed liver cancer (ie, hepatocellular carcinoma [HCC]) through data linkage with the Taiwan Cancer Registry and national health death certification in 1991–2014. A Cox proportional hazards model was utilized to assess the association between exposure to PM_2.5 metal component and HCC.

Results: We identified 322 newly developed HCC with a median follow-up of 23.1 years. Long-term exposure to PM_2.5 Cu was positively associated with a risk of liver cancer. The adjusted hazard ratio (HR) was 1.13 (95% confidence interval [CI], 1.02–1.25; P = 0.023) with one unit increment on Cu normalized by PM_2.5 mass concentration in the logarithmic scale. The PM_2.5 Cu-HCC association remained statistically significant with adjustment for co-exposures to other metal constituents in PM_2.5.

Conclusion: Our findings suggest PM_2.5 containing Cu may attribute to the association of PM_2.5 exposure with liver cancer.

Background: The present genome-wide association study (GWAS) aimed to reveal the genetic loci associated with folate metabolites as well as to detect related gene-environment interactions in Japanese.

Methods: We conducted the GWAS of plasma homocysteine (Hcy), folic acid (FA), and vitamin B₁₂ (VB₁₂) levels in the Japan Multi-Institutional Collaborative Cohort (J-MICC) Study participants who joined from 2005 to 2012, and also estimated gene-environment interactions. In the replication phase, we used data from the Yakumo Study conducted in 2009. In the discovery phase, data of 2,263 participants from four independent study sites of the J-MICC Study were analyzed. In the replication phase, data of 573 participants from the Yakumo Study were analyzed.

Results: For Hcy, MTHFR locus on chr 1, NOX4 on chr 11, CHMP1A on chr 16, and DPEP1 on chr 16 reached genome-wide significance (P < 5×10^-8). MTHFR also associated with FA, and FUT2 on chr 19 associated with VB₁₂. We investigated gene-environment interactions in both studies and found significant interactions between MTHFR C677T and ever drinking, current drinking, and physical activity > 33% on Hcy (β = 0.039, 0.038 and -0.054, P = 0.018, 0.021 and < 0.001, respectively) and the interaction of MTHFR C677T with ever drinking on FA (β = 0.033, P = 0.048).

Conclusions: The present GWAS revealed the folate metabolism-associated genetic loci and gene-environment interactions with drinking and physical activity in Japanese, suggesting the possibility of future personalized CVD prevention.

In an aging society, it is important to visualize the conditions of people living with diseases or disabilities, such as frailty and sarcopenia, and determine the environmental and genetic factors underlying such conditions. Atherosclerosis and arterial stiffness are key conditions between these factors and noncommunicable diseases. In 2014, we launched a population-based prospective open-cohort study, the Nagasaki Islands Study (NaIS), which was conducted in Goto City, located in the remote islands of Nagasaki Prefecture, Japan, mostly involving middle-aged and older residents. We conducted our own health checkups along with the annual standardized checkups organized by the municipality; recruited study participants; and started to follow-up with them for vital status (death), migration, and occurrence of diseases such as myocardial infarction, stroke, fracture, and human T-cell leukemia virus type 1 (HTLV-1) -associated uveitis. Our checkups were conducted as baseline surveys in different areas of Goto City during the fiscal years 2014–2016, secondary surveys during 2017–2019, and tertiary surveys since 2021, consisting of medical interviews, physical examinations, blood and urine tests, body composition measurements, osteoporosis screening, arterial stiffness measurements, carotid ultrasonography, and dental examination. A total of 4,957 residents participated in either the baseline or secondary surveys and were followed-up; and 3,594 and 3,364 residents (aged 27–96 and 28–98 years) participated in the baseline and secondary surveys, respectively. In conclusion, the NaIS has been undertaken to reveal the influence of aging and risk factors of noncommunicable diseases and disabilities, with an aim to contribute towards better healthcare in the future.

Background: Administering premixed drugs in commodity packets was first reported in Asia in 2015, but there continues to be a dearth of related population-based data. This study aimed at examining (1) the prevalence of drug packet use in the population and (2) the sociodemographic profiles, particularly gender distribution, of drug packet users.

Methods: Data were derived from a survey of 18,626 Taiwanese civilians, aged 12-64 years, using stratified, multi-stage, random sampling in 2018. Participants anonymously completed a computer-assisted self-interview on tablet computers which covered the use and problematic use of illicit drugs/inhalants, prescription drugs and other psychoactive substances, among others.

Results: Approximately 1.46% of respondents had a lifetime use of illicit drugs, with drugs in commodity packets (0.18%) being ranked the fifth-most commonly used illicit drugs, higher than nitrous oxide (0.14%) and heroin (0.09%). Ten formats of drug packets were endorsed by users. Approximately 81.6% of persons with drug packet use had a lifetime use of other illicit drugs. The correlates of the use of drugs in commodity packets were similar to those of the exclusive use of other drugs except that there was a lack of gender differences in the use of drugs in commodity packets but not in the exclusive use of other drugs.

Conclusion: Drugs in commodity packets have become a common way of administering illicit drugs in the population in Taiwan, and there were no gender differences among users. Our findings have implications for more efficient drug testing and culturally appropriate intervention for drug packet use.

Background: Associations of major risk factors for stroke with total and each type of stroke as well as subtypes of ischemic stroke and their population attributable fractions had not been examined comprehensively.

Methods: Participants of the Japan Public Health Center-based prospective (JPHC) Study Cohort II without histories of cardiovascular disease and cancer (n=14,797) were followed from 1993 through 2012. Associations of current smoking, hypertension, diabetes, overweight (body mass index ≥ 25 kg/m²), non-high-density lipoprotein cholesterol (non-HDLC) categories, low HDLC (< 40 mg/dL), urine protein, and history of arrhythmia were examined in a mutually-adjusted Cox regression model that included age and sex. Population attributable fraction (PAF) was estimated using the hazard ratios and the prevalence of risk factors among cases.

Results: Subjects with hypertension were 1.63 to 1.84 times more likely to develop any type of stroke. Diabetes, low HDLC, current smoking, overweight, urine protein, and arrhythmia were associated with risk of overall and ischemic stroke. Hypertension and urine protein were associated with risk of intracerebral hemorrhage while current smoking, hypertension, and low non-HDLC were associated with subarachnoid hemorrhage. Hypertension alone accounted for more than a quarter of stroke incidence, followed by current smoking and diabetes. High non-HDLC, current smoking, low HDLC, and overweight contributed mostly to large-artery occlusive stroke. Arrhythmia explained 13.2% of embolic stroke. Combined PAFs of all the modifiable risk factors for total, ischemic and large-artery occlusive strokes were 36.7 and 44.5% and 61.5%, respectively.

Conclusion: Although there are differences according to the subtypes, hypertension could be regarded as the most crucial target for preventing strokes in Japan.

Objectives: Most COVID-19 outbreaks in South Korea occurred through close contact in dense and closed indoor environments. However, a COVID-19 outbreak occurred in a group that camped together at an outdoor camping site in 2020, raising the need to observe precautions even when outdoors. We aimed to investigate the epidemiological characteristics and the risk factors for transmission for developing precautionary measures during outdoor activities.

Methods: A study was conducted among 10 patients during the outbreak that occurred at a domestic camping site in July 2020. The demographic and epidemiological characteristics were obtained through an epidemiological investigation; the transmission risk was evaluated through additional site visits and CCTV analysis.

Results: The incidence rate of this outbreak was 55.6%. No other common sources of exposure other than that within the campsite were identified; the outbreak possibly occurred due to transmission via close contact with infected people during mealtime and conversation throughout the camping period without implementation of adequate prevention and control measures.

Conclusion: It is the first COVID-19 outbreak that occurred at an outdoor camping site in South Korea. COVID-19 can spread even when outdoors, prevention and control measures such as maintaining social distancing and wearing a mask should be observed when a large number of people gather outdoors. To ensure safe camping, facility managers should keep the cleaning and hygiene, and users should minimize the risk of infection by following the recommended precautions while staying in public spaces.

Background: Although the effectiveness of BNT162b2 messenger RNA vaccines against the Omicron variant has been reported in several countries, data are limited in children living in Asian countries. Therefore, this study aimed to estimate the effectiveness of the pediatric primary two-dose monovalent mRNA vaccine series in preventing symptomatic coronavirus disease 2019 (COVID-19) in Japan.

Methods: We conducted a test-negative case-control study (262 test-positive cases and 259 test-negative controls) in patients aged 5–11 years who presented with COVID-19-like symptoms during the Omicron BA.2- and BA.5-predominant periods. Vaccination status, demographic data, underlying medical conditions, lifestyle, personal protective health behaviors, living environment, and PCR test results were obtained using parent-administered questionnaires and clinical records. Vaccine effectiveness (VE) against symptomatic COVID-19 was calculated using a multivariate logistic regression analysis.

Results: Of the test-positive cases and test-negative controls, 9.2% (n=24) and 12.7% (n=33) received two vaccine doses, respectively. Having siblings and a BA.5-dominant period were significantly associated with symptomatic COVID-19. After adjusting for age, siblings, study period, and duration after the last vaccination, the overall VE of two-dose vaccination was 50.0% (95% confidence interval [CI], 5%–74%). VE was 72% (95%CI: 24%–89%) within 3 months after the two-dose vaccination, while it decreased to 24% (95%CI: -80% to 68%) after 3 months.

Conclusion: Two BNT162b messenger RNA vaccine doses provided moderate protection against symptomatic COVID-19 during the Omicron variant period. A time-dependent decrease in VE was noted after the second dose; thus, a booster dose 3 months after the second dose is warranted.

Background: We aimed to clarify whether differences in food group intake according to household income have changed over the last decade in Japanese people aged 20 years or older.

Methods: This cross-sectional study was based on the 2010, 2014, and 2018 National Health and Nutrition Surveys in Japan. Food intake was assessed using a 1-day semi-weighed household dietary record. The participants were categorized into three groups based on their income. The mean of each food intake according to the income group was estimated by adjusting for age, occupation, and number of participants from the same household. The significance of the interaction terms between income and survey year was evaluated to assess the change in income-related differences in food intake over time.

Results: Cereal intake was lower in the middle- and the highest-income groups than in the lowest-income group, regardless of sex, and the interaction between income and year was nonsignificant for cereal intake. In the former two surveys, vegetable intake was higher among the highest-income women, while in the 2018 survey, the vegetable intake decreased in the women in the middle- and the highest-income groups. The interaction between income and year was significant for vegetable intake among the women. For other foods, the differences in intake among the income groups did not significantly change over time.

Conclusion: The tendency for lower cereal intake in the higher-income groups was consistent over time in both the sexes, and the tendency for higher vegetable intake in the highest income women disappeared over time.

Background: While tall stature has been linked to an increase in the risk of colorectal cancer (CRC), its association with cancer in the colorectum and its subsites remains unclear among Asians.

Methods: We conducted a pooled analysis of 10 population-based cohort studies among adults in Japan. Each study estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for CRC incidence associated with adult height were estimated using Cox proportional hazards regression with adjustment of the same set of covariates were then pooled to estimate summary HRs incidence using random-effect models.

Results: We identified 9,470 CRC incidences among 390,063 participants during 5,672,930 person-years of follow-up. Men and women with tall stature had a higher risk of CRC and colon cancer. HRs for CRC, colon cancer, and distal colon cancer for the highest versus lowest height categories were 1.23 (95% CI, 1.07–1.40), 1.22 (95% CI, 1.09–1.36), and 1.27 (95% CI, 1.08–1.49), respectively, in men and 1.21 (95% CI, 1.09–1.35), 1.23 (95% CI, 1.08–1.40), and 1.35 (95% CI, 1.003–1.81), respectively, in women. The association with proximal colon cancer and rectal cancer was less evident in both sexes.

Conclusion: This pooled analysis confirms the link between tall stature and a higher risk of CRC and colon cancer (especially distal colon) among the Japanese and adds evidence to support the use of adult height to identify those at a higher risk of CRC.

Introduction: The burden of epilepsy is thought to be high but is difficult to measure. Very few studies in Japan have attempted to estimate prevalence and incidence rates of epilepsy in Japan.

Methods: This retrospective cohort study used commercially collected nationwide insurance claims data from a cohort of 10 million persons between 2012 and 2019 among those aged 0 to 74 years. Using the claims data, cases were identified, and incidence and prevalence rates were estimated.

Results: A total of 9,864,278 persons were included. The average age was 34.5 (standard deviation, 18.5) years. A total of 77,312 persons were diagnosed with epilepsy over the 8-year observation period, with a prevalence rate of 6.0 per 1,000 persons with almost no difference by gender. The highest rates were seen among those aged 70–74 years; prevalence rates tended to rise with calendar year (5.4/1,000 in 2012 and 6.0/1,000 in 2019). The incidence rate of epilepsy was 72.1 per 100,000 person-years with slightly higher rates seen among females. Incidence rates were highest at ages less than 12 months (199.8/100,000 person-years), followed by the eldest age group (70–74 years, 179.4/100,000 person-years).

Conclusion: Understanding the magnitude of disease burden is the basis of determining health policies. In this study, the prevalence and incidence of epilepsy in Japan was shown based on the analysis results of a large-scale general population insurance claims data covering all over Japan.

Background: This study aimed to examine the association between risk of brain tumors and radiofrequency (RF) exposure from mobile phones among young people in Korea and Japan.

Methods: This case-control study of brain tumors in young people was conducted in Korea and Japan under the framework of the international MOBI-Kids study. We included 118 patients diagnosed with brain tumors between 2011 and 2015 and 236 matched appendicitis controls aged 10–24 years. Information on mobile phone use was collected through face-to-face interviews. A detailed RF exposure algorithm, based on the MOBI-Kids algorithm and modified to account for the specificities of Japanese and Korean phones and networks, was used to calculate the odds ratios (ORs) for total cumulative specific energy using conditional logistic regression.

Results: The adjusted ORs in the highest tertile of cumulative call time at 1 year before the reference date were 1.61 (95% confidence interval [CI], 0.72-3.60) for all brain tumors and 0.70 (95% CI, 0.16-3.03) for gliomas, with no indication of a trend with exposure. The ORs for glioma specifically, were below 1 in the lowest exposure category.

Conclusions: This study provided no evidence of a causal association between mobile phone use and risk of brain tumors as a whole or glioma specifically. Further research will be required to evaluate the impact of newer technologies of communication in the future.

Background: Little is known about the trends of imported infectious diseases among travelers to non-endemic countries during the COVID-19 pandemic. This article aimed to describe those among travelers to Japan.

Methods: This is a descriptive study based on national surveillance data. Imported infectious disease cases were defined as those with a reported overseas source of infection among 15 diseases pre-selected based on the probability and impact of importation. The number of notified cases from April 2016 to March 2021 were described by disease and time of diagnosis. The relative ratio and absolute difference in case counts—both by number and per arrival—were calculated by disease comparing those from the pandemic period (April 2020–March 2021) to the pre-pandemic period (April 2016–March 2020).

Results: A total of 3524 imported infectious disease cases were diagnosed during the study period, including 3439 cases before and 85 cases during the pandemic. The proportionate distribution of diseases changed but notification counts of all 15 diseases decreased during the pandemic. Accounting for arrivals, however, seven diseases showed a two-fold or greater increase, with a notable absolute increase per million arrivals for amebiasis (60.1; 95%CI, 41.5–78.7), malaria (21.7; 10.5–33.0), and typhoid fever (9.3; 1.9–16.8).

Conclusion: The epidemiology of imported infectious diseases changed during the pandemic. While the number of imported infectious disease cases decreased, the number of cases per arrivals increased considerably both in relative and absolute terms for several diseases of public health and clinical importance.

Background: Despite the widespread practice of Japanese traditional Kampo medicine, the characteristics of patients receiving various Kampo formulations have not been documented in detail. We applied a machine learning model to a health insurance claims database to identify the factors associated with the use of Kampo formulations.

Methods: A 10% sample of enrollees of the JMDC Claims Database in 2018 and 2019 was used to create the training and testing sets, respectively. Logistic regression analyses with lasso regularization were performed in the training set to construct models with prescriptions of 10 commonly used Kampo formulations in 1 year as the dependent variable and data of the preceding year as independent variables. Models were applied to the testing set to calculate the C-statistics. Additionally, the performance of simplified scores using 10 or 5 variables were evaluated.

Results: There were 338,924 and 399,174 enrollees in the training and testing sets, respectively. The commonly prescribed Kampo formulations included kakkonto, bakumondoto, and shoseityuto. Based on the lasso models, the C-statistics ranged from 0.643 (maoto) to 0.888 (tokishakuyakusan). The models identified both the common determinants of different Kampo formulations and the specific characteristics associated with particular Kampo formulations. The simplified scores were slightly inferior to full models.

Conclusion: Lasso regression models showed good performance for explaining various Kampo prescriptions from claims data. The models identified the characteristics associated with Kampo formulation use.

Background: Although many observational studies have demonstrated significant relationships between obesity and cardiometabolic traits, the causality of these relationships in East Asians remains to be elucidated.

Methods: We conducted individual-level Mendelian randomization (MR) analyses targeting 14,083 participants in the Japan Multi-Institutional Collaborative Cohort Study and two-sample MR analyses using summary statistics based on genome-wide association study data from 173,430 Japanese. Using 83 body mass index (BMI)-related loci, genetic risk scores (GRS) for BMI were calculated, and the effects of BMI on cardiometabolic traits were examined for individual-level MR analyses using the two-stage least squares estimator method. The β-coefficients and standard errors for the per-allele association of each single-nucleotide polymorphism as well as all outcomes, or odds ratios with 95% confidence intervals were calculated in the two-sample MR analyses.

Results: In individual-level MR analyses, the GRS of BMI was not significantly associated with any cardiometabolic traits. In two-sample MR analyses, higher BMI was associated with increased risks of higher blood pressure, triglycerides, and uric acid, as well as lower high-density-lipoprotein cholesterol and eGFR. The associations of BMI with type 2 diabetes in two-sample MR analyses were inconsistent using different methods, including the directions.

Conclusion: The results of this study suggest that, even among the Japanese, an East Asian population with low levels of obesity, higher BMI could be causally associated with the development of a variety of cardiometabolic traits. Causality in those associations should be clarified in future studies with larger populations, especially those of BMI with type 2 diabetes.

Background: Psychological stress can cause various mental and physical health problems. The previous results on stress and oral health are inconsistent, possibly because of the narrow stress measurements. We aimed to examine the association between a broader range of stressful life events and oral health among workers.

Methods: This cross-sectional study analyzed anonymous individual data from a national survey in Japan. Data on stressful life events, oral health problems which are one or more of tooth pain, gum swelling/bleeding, and difficulty chewing, and covariates were obtained using a self-reported questionnaire. Covariates used included gender, age group, and disease under treatment. Logistic regression analysis was used to estimate the association between stressful life events and oral health problems. We then estimated the causal treatment effects of stress using the augmented inverse-probability weighting (AIPW) method.

Results: Among the 274,881 subjects, 152,850 men (55.6%) and 122,031 women (44.4%) with a mean age of 47.0 (standard deviation, 14.4) years, 4.0% reported oral health problems, with a prevalence of 2.1% among those without any stress. The prevalence increased with stress score, reaching 15.4% for those with the maximum stress score. The adjusted odds ratio of this group compared to those without any stress was 9.2 (95% confidence interval [CI], 8.2–10.3). The estimated prevalence of oral health problems by the AIPW analysis was 2.2% (95% CI, 2.1–2.3%) for those without any stress and 14.4% (95% CI, 12.1–16.7%) for those with the maximum stress scores.

Conclusion: There was a clear dose-response association between stressful life events and oral health problems.

Background: Diabetes and prediabetes have been linked with morbidity or mortality from cardiovascular disease, cancer, or other physical disorders among working-age populations, but less is known about outcomes directly related to labor loss (eg, long-term sickness absence [LTSA] or pre-retirement death due to physical disorders).

This prospective study aimed to examine the association of diabetes and prediabetes with the risk of a composite outcome of LTSA and pre-retirement death due to physical disorders. The present study also examined the associations of severe outcomes (LTSA or death) due to specific physical disorders or injuries/external causes in relation to diabetes and prediabetes.

Methods: Data were derived from the Japan Epidemiology Collaboration on Occupational Health study. A total of 60,519 workers from 12 companies were followed for 8 years. Diabetes and prediabetes were defined based on the American Diabetes Association criteria. A Cox proportional hazards regression model was used to examine the association between diabetes/prediabetes and severe outcomes due to physical disorders or injuries/external causes.

Results: The adjusted hazard ratios of severe outcomes due to all physical disorders were 1.22 (95% confidence interval [CI], 1.02–1.45) and 2.32 (95% CI, 2.04–2.64) for prediabetes and diabetes, respectively. In cause-specific analyses, an increased risk was observed for severe outcomes due to cancers, cardiovascular diseases, diseases of the musculoskeletal system, and injuries/external causes in relation to either or both diabetes and prediabetes.

Conclusion: Diabetes and prediabetes were associated with an increased risk of severe outcomes due to physical disorders or injuries/external causes among Japanese workers.

Background: The logistic regression analysis proposed by Schouten et al (Stat Med. 1993;12:1733–1745) has been a standard method in current statistical analysis of case-cohort studies, and it enables effective estimation of risk ratios from selected subsamples, with adjustment of potential confounding factors. Schouten et al (1993) also proposed the standard error estimate of the risk ratio estimator can be calculated using the robust variance estimator, and this method has been widely adopted.

Methods and Results: The robust variance estimator does not account for the duplications of case and subcohort samples and generally has certain bias (ie, inaccurate confidence intervals and P-values are possibly obtained). To address the invalid statistical inference problem, we provide an alternative bootstrap-based valid variance estimator. Through simulation studies, the bootstrap method consistently provided more precise confidence intervals compared with those provided using the robust variance method, while retaining adequate coverage probabilities.

Conclusion: The robust variance estimator has certain bias, and inadequate conclusions might be deduced from the resultant statistical analyses. The proposed bootstrap variance estimator can provide more accurate and precise interval estimates. The bootstrap method would be an alternative effective approach in practice to provide accurate evidence.

Background: In Japan, sentinel surveillance is used to monitor the trend of infectious gastroenteritis. Another method of pathogen surveillance, wastewater-based epidemiology, has been used recently because it can help to monitor infectious disease without relying on patient data. Here, we aimed to determine the viral trends reflected in the number of reported patients and number of gastroenteritis virus-positive samples. We focused on gastroenteritis viruses present in wastewater and investigated the usefulness of wastewater surveillance for the surveillance of infectious gastroenteritis.

Methods: Real-time polymerase chain reaction was used for viral gene detection in wastewater. The number of reported patients per pediatric sentinel site and number of viral genome copies were compared for correlation potential. The number of gastroenteritis virus-positive samples reported by NESID and a status of gastroenteritis viruses detected in wastewater were also evaluated.

Results: Genes of norovirus GI, norovirus GII, sapovirus, astrovirus, rotavirus group A, and rotavirus group C were detected in wastewater samples. Viruses were detected in wastewater during periods when no gastroenteritis virus-positive samples were reported to NESID.

Conclusions: Norovirus GII and other gastroenteritis viruses were detected in wastewater even during periods when no gastroenteritis virus-positive samples were found. Therefore, surveillance using wastewater can complement sentinel surveillance and is an effective tool for the surveillance of infectious gastroenteritis.

Background: Glomerular hyperfiltration has been reported to be associated with adverse renal outcomes in general population. It is not known whether drinking pattern is associated with the risk of glomerular hyperfiltration in healthy individuals.

Methods: We prospectively followed middle-aged 8,640 Japanese men with normal renal function, no proteinuria, no diabetes, and no use of antihypertensive medications at entry. Data on alcohol consumption were gathered by questionnaire. Glomerular hyperfiltration was defined as estimated glomerular filtration rate (eGFR) ≥117 mL/min/1.73 m², which was the upper 2.5th percentile value of eGFR in the entire cohort.

Results: During 46,186 person-years of follow-up, 330 men developed glomerular hyperfiltration. In a multivariate model, for men who consumed alcohol on 1–3 days per week, alcohol consumption of ≥69.1g ethanol/drinking day was significantly associated with the risk of glomerular hyperfiltration (hazard ratio (HR), 2.37 (95% CI, 1.18–4.74)) compared with non-drinkers. For those who consumed alcohol on 4–7 days per week, higher alcohol consumption per drinking day was associated with a higher risk of glomerular hyperfiltration: the HRs (95% CI) for alcohol consumption of 46.1–69.0, and ≥69.1 g ethanol/drinking day were 1.55 (1.01–2.38), and 1.78 (1.02–3.12), respectively.

Conclusions: For high drinking frequency per week, more alcohol intake per drinking day was associated with an increased risk of glomerular hyperfiltration, while for low drinking frequency per week, only very high alcohol intake per drinking day was associated with an increased risk of glomerular hyperfiltration in middle-aged Japanese men.

Background: This study aimed to develop models to predict the 5-year incidence of T2DM in a Japanese population and validate them externally in an independent Japanese population.

Methods: Data from 10,986 participants (aged 46–75 years) in the development cohort of the Japan Public Health Center-based Prospective Diabetes Study and 11,345 participants (aged 46–75 years) in the validation cohort of the Japan Epidemiology Collaboration on Occupational Health Study were used to develop and validate the risk scores in logistic regression models.

Results: We considered non-invasive (sex, body mass index, family history of diabetes mellitus, and diastolic blood pressure) and invasive (glycated hemoglobin [HbA1c] and fasting plasma glucose [FPG]) predictors to predict the 5-year probability of incident diabetes. The area under the receiver operating characteristic curve was 0.643 for the non-invasive risk model, 0.786 for the invasive risk model with HbA1c but not FPG, and 0.845 for the invasive risk model with HbA1c and FPG. The optimism for the performance of all models was small by internal validation. In the internal-external cross-validation, these models tended to show similar discriminative ability across different areas. The discriminative ability of each model was confirmed using external validation datasets. The invasive risk model with only HbA1c was well-calibrated in the validation cohort.

Conclusions: Our invasive risk models are expected to discriminate between high- and low-risk individuals with T2DM in a Japanese population.

Background: Hypertension is one of the most common chronic diseases, and dietary factors play an important role in hypertension. We examined the interaction of dietary sodium-to-potassium (Na/K) ratio and dinner energy ratio on hypertension.

Methods: We conducted this study using data from the cross-sectional National Survey for Nutrition and Adult Chronic Disease in 2015 in Inner Mongolia, China. Dietary data were collected using 24-hour diet records with food weights across 3 consecutive days. Logistic regression was used to determine the interaction of dinner energy ratio and dietary Na/K ratio on hypertension.

Results: A total of 1,861 participants were included in this study, and 914 individuals were hypertensive (49.1%). Dinner energy ratio and high dietary Na/K ratio were independently related to high prevalence of hypertension. A formal test showed that dinner energy ratio interacted significantly with dietary Na/K ratio on hypertension (P < 0.001), with an adjusted odds ratio (OR) of 1.119 (95% confidence interval [CI], 1.040–1.203). Participants whose dinner energy ratio greater than 39.1% and dietary Na/K ratio of 3.625–6.053 had the highest OR of hypertension prevalence, with an adjusted OR of 2.984 (95% CI, 1.758–5.066), compared with participants with dinner energy ratio of 30.2–39.1%, and dietary Na/K ratio less than 2.348.

Conclusion: Our study highlighted the interactive effect of dinner energy ratio and dietary Na/K ratio on hypertension among adults in Inner Mongolia. We advocated a balanced diet (dinner energy ratio not small or large) and a low dietary Na/K ratio for reducing the prevalence of hypertension.

Background: No studies in Japan have examined whether dispensing by family pharmacists, who are incentivized by reimbursement to provide continuous and exclusive medication management, results in prescription changes. Our primary objective was to identify the variables affecting prescription changes, particularly to investigate dispensing by family pharmacists as a possible factor.

Methods: We identified 333,503 records of pharmacy claims data from patients aged 65 years or older who received medication instructions at outpatient pharmacies at Tsukuba, a medium-sized city near Tokyo, between April 2018 and March 2019. We extracted data on dispensing by family pharmacists, number of medicines, patient sex, patient age, and pharmacy category. A multilevel modified Poisson regression analysis was performed to analyze the correlation between dispensing by family pharmacists and pharmacist-initiated prescription change.

Results: Dispensing by family pharmacists was 1.37 times more likely to involve a record of prescription change than dispensing by non-family pharmacists. Older age, female sex, polypharmacy, and small-scale pharmacies were also found to be factors.

Conclusion: This study indicated that dispensing by family pharmacists was a potential factor for pharmacist-initiated prescription changes that may prevent excessive medication and limit pharmacological interactions. Since the likelihood of inappropriate prescriptions being issued varies from hospital to hospital, subsequent studies should take into account the quality of each institution.

Background: The association between chronic lipopolysaccharide exposure and the development of metabolic syndrome (MetS) is unclear. In this study we examined the association between serum lipopolysaccharide-binding protein (LBP) levels, an indicator of lipopolysaccharide exposure, and the development of MetS in a general Japanese population.

Methods: 1,869 community-dwelling Japanese individuals aged ≥40 years without MetS at baseline examination in 2002–2003 were followed up by repeated examination in 2007–2008. MetS was defined according to the Japanese criteria. Serum LBP levels were classified into quartiles (quartiles 1–4: 2.20–9.56, 9.57–10.78, 10.79–12.18, and 12.19–24.34 µg/mL, respectively). Odds ratios (ORs) for developing MetS were calculated using a logistic regression model.

Results: At the follow-up survey, 159 participants had developed MetS. Higher serum LBP levels were associated with greater risk of developing MetS after multivariable adjustment for age, sex, smoking, drinking, and exercise habits (OR [95% confidence interval] for quartiles 1–4: 1.00 [reference], 2.92 [1.59–5.37], 3.48 [1.91–6.35], and 3.86 [2.12–7.03], respectively; P for trend <0.001). After additional adjustment for homeostasis model assessment of insulin resistance, this association was attenuated but remained significant (P for trend = 0.007). On the other hand, no significant association was observed after additional adjustment for serum high-sensitivity C-reactive protein (P for trend = 0.07).

Conclusion: In the general Japanese population, our findings suggest that higher serum LBP levels are associated with elevated risk of developing MetS. Low-grade endotoxemia could play a role in the development of MetS through systemic chronic inflammation and insulin resistance.

Purpose: Although examining the dose-response curves of physical activity (PA) and sitting time with health-related outcomes is an important research agenda, the results for older Japanese adults are extremely limited. We examined the dose-response associations of PA and sitting time with all-cause mortality among older Japanese.

Methods: Initially, 8,069 non-disabled residents (4,073 men; 3,996 women) aged 65–84 years of Ota City, Japan, were analyzed. Moderate-to-vigorous PA (MVPA) and sitting time were evaluated using the International Physical Activity Questionnaire-Short Form. Multivariate-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) of MVPA and sitting time for all-cause mortality were calculated, and the dose-response curves were examined using restricted cubic splines (RCS).

Results: During 4.1 years of follow-up, 458 participants (5.7%; 331 men and 127 women) died. Compared with the low MVPA (<600 metabolic equivalents [METs]·minutes/week) group, HR for mortality gradually reduced in moderate (600–3,000 METs·minutes/week) and high (>3,000 METs·minutes/week) MVPA groups (moderate: HR 0.66; 95% CI, 0.54–0.82; high: HR 0.58; 95% CI, 0.45–0.75; P < 0.001 for trend). RCS showed that the HR for mortality reduced linearly up to approximately 2,000 METs·minutes/week of MVPA, and maximal risk reduction was seen at approximately 3,000–4,500 METs·minutes/week of MVPA. No significant dose-response association of sitting time with mortality was observed.

Conclusion: Higher MVPA levels reduced all-cause mortality risk, in a significant inverse non-linear dose-response manner. Sitting time was not significantly associated with all-cause mortality. It is important to disseminate the significance of even a slight increase in the MVPA for reducing mortality risk.

Background: Although fat mass index (FMI) and fat-free mass index (FFMI) affect lung function, FMI and FFMI are not independent of each other since FMI and FFMI were calculated as fat mass and fat-free mass divided by height squared, respectively. We aimed to examine the association of combined FMI and FFMI with lung function.

Methods: In this cross-sectional study, lung function was evaluated using forced expiratory volume at 1 s and forced vital capacity was measured using spirometry. Both FMI and FFMI were classified into sex-specific quartiles (16 groups). Analysis of covariance was used to assess the associations of combined FMI and FFMI with lung function. The trend test was conducted by stratifying the FMI and FFMI, scoring the categories from 1–4 (lowest–highest), and entering the number as a continuous term in the regression model.

Results: This study included 3,736 men and 8,821 women aged ≥20 years living in Miyagi Prefecture, Japan. The mean FEV₁ (standard deviation) was 3.0 (0.7) L for men and 2.3 (0.5) L for women. The mean FVC was 3.8 (0.7) L for men and 2.8 (0.5) L for women. The FMI was inversely associated with lung function among all FFMI subgroups in both sexes. Conversely, FFMI was positively associated with lung function in all FMI subgroups in both sexes.

Conclusions: Higher FMI was associated with lower lung function independent of FFMI; higher FFMI was associated with higher lung function independent of FMI. Reducing FMI and maintaining FFMI might be important for respiratory health.

Background: For therapeutic efficacy, molnupiravir and nirmatrelvir-ritonavir must be started to treat patients within 5 days of disease onset to treat patients with COVID-19. However, some patients spend more than 5 days from disease onset before reporting to the Public Health Office. This study aimed to clarify the characteristics of patients with reporting delay.

Methods: This study included data from 12,399 patients with COVID-19 who reported to the Public Health Office from March 3^rd, 2021 to June 30^th, 2021. Patients were stratified into “linked” (n=7,814) and “unlinked” (n=4,585) cases depending on whether they were linked to other patients. A long reporting delay was defined as the difference between the onset and reporting dates of 5 days or more. Univariate and multivariate analyses were performed using log-binomial regression to identify factors related to long reporting delay, and prevalence ratios with corresponding 95% confidence intervals were calculated.

Results: The proportion of long reporting delay was 24.4% (1904/7814) and 29.3% (1344/4585) in linked and unlinked cases, respectively. Risks of long reporting delay among linked cases were living alone and onset on the day with a higher 7-day daily average confirmed cases or onset on weekends; whereas, risks for unlinked cases were age over 65 years, without occupation and living alone.

Conclusion: Our results suggest the necessity to establish a Public Health Office system that is less susceptible to the rapid increase in the number of patients, promotes educational activities for people with fewer social connections, and improves access to health care.

Background: Although cigarette smoking is an established risk factor for bladder cancer, assessment of smoking impact on bladder cancer in Asian populations has been hindered by few cohort studies conducted in Asian populations. Therefore, we investigated the risk of bladder cancer associated with smoking status, cumulative smoking intensity, and smoking cessation in Japan.

Methods: We analyzed data for 157,295 men and 183,202 women in 10 population-based cohort studies in Japan. The risk associated with smoking behaviors was estimated using Cox regression models within each study, and pooled hazard ratios (HRs) and their 95% confidence intervals (CIs) for the incidence of bladder cancer were calculated.

Results: During 4,729,073 person-years of follow-up, 936 men and 325 women developed bladder cancer. In men, former smokers (HR 1.47; 95% CI, 1.18–1.82) and current smokers (HR 1.96; 95% CI, 1.62–2.38) had higher risk than never smokers. In women, current smokers had higher risk than never smokers (HR 2.35; 95% CI, 1.67–3.32). HRs in men linearly increased with increasing pack-years. Risk decreased with increasing years of smoking cessation in men, with a significant dose-response trend. Former smokers with a duration of more than 10 years after smoking cessation had no significantly increased risk compared with never smokers (HR 1.26; 95% CI, 0.97–1.63).

Conclusion: Data from a pooled analysis of 10 population-based cohort studies in Japan clearly show an association between cigarette smoking and bladder cancer risk. The risk of smokers may approximate that of never smokers following cessation for many years.

Background: This cohort study aimed to estimate incidence rates of femoral shaft fracture in patients who were treated with antiresorptive drugs.

Methods: We used data from the National Database of Health Insurance Claims of Japan from April 2009 and October 2016. All patients with new use of an antiresorptive drug, prescription-free period of ≥3 months, and no prior femoral fractures were included. Femoral shaft fractures were identified using a validated definition based on International Classification of Diseases, 10^th revision (ICD-10) codes. Incidence rate ratios were estimated using Poisson regression, with adjustment for sex, age, and the Charlson Comorbidity Index.

Results: We identified 7,958,655 patients (women: 88.4%; age ≥75 years: 51.2%). Femoral shaft fractures were identified in 22,604 patients. Incidence rates per 100,000 person-years were 74.8 for women, 30.1 for men, 30.1 for patients aged ≤64 years, 47.7 for patients aged 65–74 years, and 99.0 for patients aged ≥75 years. Adjusted incidence rate ratios in patients taking versus not taking each type of antiresorptive drug were 1.00 (95% confidence interval [CI], 0.98–1.03) for bisphosphonates, 0.46 (95% CI, 0.44–0.48) for selective estrogen receptor modulators, 0.24 (95% CI, 0.18–0.32) for estrogens, 0.75 (95% CI, 0.71–0.79) for calcitonins, and 0.93 (95% CI, 0.84–1.03) for denosumab. The adjusted incidence rate ratio for alendronate was 1.18 (95% CI, 1.14–1.22).

Conclusion: The incidence rates of femoral shaft fracture varied across patients treated with different antiresorptive drugs. Further research on a specific antiresorptive drug can increase understanding of the risk of femoral shaft fracture.

Background: The 2011 Great East Japan Earthquake has resulted in a nuclear accident, forcing residents of the surrounding areas to evacuate. To determine any association between excessive drinking and hypertension in the setting of disaster, we assessed whether the proportion of excessive drinkers increased and if post-disaster excessive drinking was a risk factor for hypertension.

Methods: This retrospective study assessed data from the Japanese National Database. Cumulative population data for Fukushima Prefecture (3,497,576 people) were analyzed by categorizing residents into four areas—evacuation, coastal, central, and mountainous—to calculate the proportion of excessive, heavy (equivalent to binge drinking), and at-risk drinkers for 2008–2017. The hazard ratios (HRs) for the incidence of hypertension for 2012–2017 were examined in association with changes in drinking status pre- and post-disaster, which included 136,404 people who received specific health checkups pre-disaster (2008–2010) and post-disaster (2011–2012).

Results: The proportion of excessive drinkers among women increased after the disaster in all areas examined. The association between excessive drinking and the incidence of hypertension was determined among men and women in all areas; it was stronger among women in the evacuation areas, with the sex- and age-adjusted HRs for the incidence of hypertension of 1.41 for pre-disaster excessive drinking, 2.34 for post-disaster excessive drinking, and 3.98 for pre- and post-disaster excessive drinking, compared with not excessive drinking pre- and post-disaster.

Conclusion: Excessive drinking post-disaster may be associated with an increased risk of hypertension among men and women, especially among women in the evacuation areas.

Background: In 2016, two consecutive moderate magnitude earthquakes occurred in Ulsan, South Korea. Therefore, we aimed to investigate the impact of earthquakes on the mental health of residents in Ulsan.

Methods: We used data from the 2015–2017 Korean Health Insurance Review & Assessment Service National Patient Sample. We conducted an interrupted time series analysis using location-based controls. Changes in the number of antidepressants, benzodiazepines, and zolpidem prescriptions in Ulsan were compared to controls. Overall changes in weekly prescriptions 1 year after the first earthquake, compared to a non-earthquake scenario, were estimated.

Results: In antidepressant prescriptions, the increase in trend after an earthquake was significantly higher than controls. However, the changes in benzodiazepines and zolpidem prescribing were not significant. Overall, the impact of the earthquake on weekly antidepressant prescriptions at 1 year was estimated as a 1.32 (95% CI, 1.18–1.56) rate ratio compared to the non-earthquake scenario. This corresponded to an increase of 1,989.7 (95% CI, 1,202.1–3,063.0) in the number of prescriptions. Among subgroups, the increase was highest among males aged 20–39 years.

Conclusion: The moderate earthquake in Ulsan was associated with an increase in antidepressant prescriptions. The increase in the male group aged 20–39 was the highest. The impact may vary according to the context of the population.

Background: The neurological prognosis of asphyxia is poor and the effect of advanced airway management (AAM) in the prehospital setting remains unclear. This study aimed to evaluate the association between AAM with adrenaline injection and prognosis in adult patients with asystole asphyxia out-of-hospital cardiac arrest (OHCA).

Methods: This study assessed all-Japan Utstein cohort registry data between January 1, 2013 and December 31, 2019. We used propensity score matching analyses before logistic regression analysis to evaluate the effect of AAM on favorable neurological outcome.

Results: There were 879,057 OHCA cases, including 70,299 cases of asphyxia OHCAs. We extracted the data of 13,642 cases provided with adrenaline injection by emergency medical service. We divided 7,945 asphyxia OHCA cases in asystole into 5,592 and 2,353 with and without AAM, respectively. After 1:1 propensity score matching, 2,338 asphyxia OHCA cases with AAM were matched with 2,338 cases without AAM. Favorable neurological outcome was not significantly different between the AAM and no AAM groups (adjusted odds ratio [OR] 1.1; 95% confidence interval [CI], 0.5–2.5). However, the return of spontaneous circulation (ROSC) (adjusted OR 1.7; 95% CI, 1.5–1.9) and 1-month survival (adjusted OR 1.5; 95% CI, 1.1–1.9) were improved in the AAM group.

Conclusion: AAM with adrenaline injection for patients with asphyxia OHCA in asystole was associated with improved ROSC and 1-month survival rate but showed no differences in neurologically favorable outcome. Further prospective studies may comprehensively evaluate the effect of AAM for patients with asphyxia.

Background: We sought to establish a prospective hospital-based cohort, featuring detailed multidimensional data of trauma patients with active follow-ups, which can be a reliable data source for all studies focusing on the effects or underlying mechanistic pathways of environmental and biological factors on multiple interested trauma-related outcomes, particularly the incidence and trajectory of trauma-related psychopathology, in a Chinese population.

Methods: The China Severe Trauma Cohort (CSTC) enrolled all traumatized individuals aged 12 to 80 years admitted to the Trauma Center of West China Hospital between March 1^st, 2020 and July 8^th, 2022. The bio-sample and detailed questionnaire data were collected at recruitment, and phone/internet follow-ups were scheduled at 1, 3, 6, and 12 months after the baseline. Long-term health outcomes are planned to be obtained from administrative databases through data linkage.

Results: A total of 2,500 trauma patients were enrolled (response rate = 87.1%) with an average age of 46.01 years, and most of the participants were males (62.6%). The proportions of participants with blood and fecal sample collected at baseline were 93.8% and 66.3%, respectively. As of August 31^st, 2022, the follow-up rate was 90.0%, 77.0%, 76.5%, and 89.0% for 1-, 3-, 6-, and 12-month follow-ups, respectively. Fall/wrench (47.6%) and traffic accident (26.2%) were the top causes of current trauma. The most common psychopathology at recruitment was sleep disturbance (39.4%), followed by depression (22.6%), anxiety (18.2%), and acute stress reaction (7.8%), all of which showed recovering trajectories during the follow-up period, particularly the first 3 months after baseline.

Conclusion: CSTC provides a platform with multidimensional data to study both short-term and long-term trauma-related health consequences, prompting early identification and intervention for individuals with high risk of health decline after trauma exposures.

Background

The possible association between cigarette smoking and breast cancer risk has been quite controversial.

Methods

We conducted a systematic review and meta-analysis of all available observational studies published on the issue up to January 2020. Random-effects models were used to compute pooled relative risks (RRs) for cigarette smoking status and dose-risk relationships were evaluated using one-stage random-effects dose-response models.

Results

A total of 169 studies were selected, providing a pooled RR for breast cancer of 1.07 (95% confidence interval, CI, 1.05-1.10) for current, 1.08 (95% CI 1.06-1.10) for former, and 1.09 (95% CI 1.07-1.11) for ever smokers, compared to never smokers. Results were consistent in case-control and cohort studies. No meaningful differences were observed across strata of most covariates considered, nor according to relevant genetic mutations and polymorphisms (i.e., BRCA mutation, N-acetyltransferase and glutathione S-transferase genotypes, and P53). Breast cancer risk increased linearly with intensity of smoking (RR 1.12, 95% CI 1.08-1.16, for 20 and 1.26, 95% CI 1.17-1.36 for 40 cigarettes/day), and with increasing duration of smoking (RR 1.05, 95% CI 1.03-1.08, for 20 and 1.11, 95% CI 1.06-1.16, for 40 years of smoking).

Conclusions

The present large and comprehensive meta-analysis – conducted using an innovative approach for study search – supports the evidence of causal role of tobacco smoking on breast cancer risk.

Backgrounds: We aimed to assess whether the U.S. developed claimed-based frailty index (CFI) can be implemented in Japanese older adults using claim data.

Methods: We used the monthly claims data and certification of long-term care (LTC) insurance data of residents from 12 municipalities from April 2014 to March 2019. The 12 months from first recording was defined as the “baseline period,” and the time thereafter as “follow-up period”. Participants aged ≥65 years and those with no certified LTC insurance or who died at baseline were included. New certification of LTC insurance and all-cause mortality during the follow-up period were defined as outcome events. CFI categorization consisted of three steps including: 1) using 12 months deficit-accumulation approach that assigned different weights to each of the 52 items; 2) the accumulated score to derive the CFI; and 3) categorizing the CFI as “robust” (<0.15), “prefrail” (0.15–0.24), and “frail” (≥0.25). Kaplan–Meier survival curves and Cox proportional hazard models were used to determine the association between CFI and outcomes. Hazard ratios (HR) and 95% confidence intervals (95%CI) were calculated.

Results: The participants were 519,941 in total. After adjusting for covariates, the severe CFI category had a high risk of certification of LTC insurance (prefrail, HR: 1.33, 95%CI:1.27-1.39; frail, HR: 1.60, 95%CI: 1.53-1.68) and all-cause mortality (prefrail, HR: 1.44, 95%CI: 1.29-1.60; frail, HR: 1.84, 95%CI: 1.66-2.05).

Conclusions: This study suggests that CFI can be implemented in Japanese claims data by predicting the certification of LTC insurance and mortality.

Background: The impact of meeting leisure-time physical activity (LTPA) recommendations and household physical activity (HPA) on all-cause mortality in the Taiwanese population is unclear. We aimed to investigate the relationship between sufficient LTPA and all-cause mortality in middle-aged and older Taiwanese adults and the role of HPA in those with insufficient LTPA.

Methods: This nationwide prospective cohort study included 4,960 participants aged ≥50 years from the Taiwan Longitudinal Study in Aging (TLSA) survey. Physical activity patterns were assessed in 2003 and then followed up until 2015 for mortality through the National Death Registration Record. Cox proportional hazards regression was conducted to evaluate hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause mortality.

Results: Of the 4,960 participants, 1,712 died of all-cause mortality. Compared to those who had insufficient LTPA, participants who engaged in sufficient LTPA showed a significantly lower risk of all-cause mortality (HR = 0.84, 95% CI, 0.73–0.97). For those with insufficient LTPA, HPA also had a significantly reduced risk of all-cause mortality (HR = 0.85, 95% CI, 0.75–0.96) among general population. Similar associations were observed in subsequent sensitivity analyses. The subgroup analysis showed that the relationship between HPA and reduced mortality risk was only found in the women with insufficient LTPA group.

Conclusion: This study confirmed that sufficient LTPA is associated with a lower risk of all-cause mortality. If sufficient LTPA cannot be performed, additional HPA is related to lower mortality.

Background: Little is known about the impacts of sleep duration and daytime napping on the risk of type 2 diabetes mellitus (T2DM).

Methods: In this study, 20,318 participants (7,597 men, 12,721 women) aged 40–79 years without a history of T2DM, stroke, coronary heart disease, or cancer at baseline (1988–1990), completed the baseline survey and the 5-year follow-up questionnaires, which included average sleep duration, napping habits, and self-reports of physician-diagnosed diabetes. The multivariable odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using a logistic regression model.

Results: During the 5-year follow-up, 531 new cases of T2DM (266 men and 265 women) were documented. Sleep duration ≥10 hours was associated with higher risk of T2DM compared to sleep duration of 7 hours (OR 1.99; 95% CI, 1.28–3.08). The excess risk was observed for both sexes and primarily found among the non-overweight; the multivariable ORs of sleeping ≥10 hours compared to 7 hours were 2.05 (95% CI, 1.26–3.35) for the non-overweight (BMI <25 kg/m²) and 1.38 (95% CI, 0.49–3.83) for the overweight (BMI ≥25 kg/m²). The respective ORs of nappers versus non-nappers were 1.30 (95% CI, 1.03–1.63) and 0.92 (95% CI, 0.65–1.29). Among the non-overweight, nappers who slept ≥10 hours had the highest risk of T2DM (OR 2.84; 95% CI, 1.57–5.14), non-nappers who slept ≥10 hours (OR 2.27; 95% CI, 1.27–4.06), and nappers who slept <10 hours (OR 1.30; 95% CI, 1.03–1.64), compared with non-nappers who slept <10 hours.

Conclusion: Long sleep duration was associated with the risk of T2DM in both sexes, which was confined to the non-overweight.

Background: Whether sleep quality and duration assessed from multiple domains, either individually or in combination, are strongly associated with mortality risk in older adults remains unelucidated. We aimed to clarify these relationships.

Methods: We enrolled 7,668 older (age ≥65 years) Japanese adults in the Kyoto-Kameoka prospective cohort study who provided valid responses to the Pittsburgh Sleep Quality Index (PSQI) in a mail-in survey. Sleep quality and duration were classified into six groups using the previously validated PSQI: short sleep duration (SSD: <360 min/day)/sleep disturbance (SD: ≥5.5 PSQI points), n = 701; SSD/non-sleep disturbance (NSD: <5.5 PSQI points), n = 100; optimal sleep duration (OSD: 360–480 min/day)/NSD, n = 1,863; OSD/SD, n = 2,113; long sleep duration (LSD: >480 min/day)/NSD, n = 1,972; LSD/SD, n = 919. Mortality data were collected from February 15, 2012, to November 30, 2016. We evaluated the relationship between all-cause mortality risk and sleep quality and duration (and their combinations) using a multivariable Cox proportional hazards model that included baseline covariates.

Results: The median follow-up period was 4.75 years (34,826 person-years), with a total of 616 deaths. After adjusting for confounders, compared with other groups, SSD/SD and LSD/SD had the highest hazard ratio (HR) of mortality (SSD/SD: HR 1.56; 95% confidence interval [CI], 1.10–2.19; SSD/NSD: HR 1.27; 95% CI, 0.47–3.48; OSD/NSD: reference; OSD/SD: HR 1.20; 95% CI, 0.91–1.59; LSD/NSD: HR 1.35; 95% CI, 1.03–1.77; LSD/SD: HR 1.83; 95% CI, 1.37–2.45). However, mortality risk was not associated with the interaction between sleep quality and duration.

Conclusion: Older adults with sleep disturbances involving SSD and LSD have a strong positive association with mortality risk, suggesting an additive effect between sleep quality and duration.