Background: Multiple tobacco product (MTP) use is a public health concern due to their combined adverse health effects. MTP use may have increased since heated tobacco products (HTPs) became more prevalent in Japan. This study aimed to (1) estimate the recent prevalence of MTP use and clarify the associated factors compared to (2) non-smokers and (3) single-product users.

Methods: We used data from an internet survey conducted in February 2022. The prevalence of MTP use in Japan was estimated using inverse probability-weighted scores from this survey and a nationwide survey by the Japanese government. Tobacco products include six types: cigarettes, HTPs, e-cigarettes, cigars, pipe/water pipes, and smokeless tobacco products. MTP use was defined using the outcome variable (no use, single-product use, and MTP use) based on these six types of use. Using multivariate logistic regression, we calculated the adjusted odds ratios and 95% confidence intervals (CI) to clarify factors associated with MTP use compared to non-smokers, adjusting demographic variables, psychological distress, self-rated health, and alcohol use. Using multivariate Poisson regression, we calculated the adjusted prevalence ratios (aPRs) and 95% CIs to clarify factors associated with MTP use among smokers, adjusting for these covariates and smoking-related factors like workplace and home smoking rules.

Results: We analyzed 30,141 participants whose mean age was 47.8 years (standard deviation, 17.9), and 14,722 participants were male (48.8%). The estimated prevalence of MTP use was 6.8%. The most common combination of MTP use was cigarettes and HTPs. Compared to non-smokers, being younger, male, alcohol drinkers, and having low education, poor psychological distress, and poor self-rated health were factors associated with MTP use. Among smokers, workplace smoking rules, such as a partial smoking ban and no smoking ban, were not associated with MTP use compared to the indoor smoking ban. However, having no home smoking ban was positively associated with MTP use compared with a ban on both cigarettes and HTPs at home (both cigarettes and HTPs allowed aPR 1.36; 95% CI, 1.15–1.61, HTPs only allowed aPR 1.73; 95% CI, 1.43–2.10).

Conclusion: MTP users may account for a high percentage of Japanese smokers.

Background: Evidence of post-COVID-19 condition (PCC) in the Alpha- and Delta-variant dominant waves is limited.

Methods: In a nationwide multicenter cohort study in collaboration with 20 hospitals, we collected data using self-administered questionnaires and electronic medical records of participants aged 20 or more diagnosed with COVID-19, hospitalized between April 1, 2021 and September 30, 2021, and discharged alive. Descriptive statistics were analyzed for PCC and mental health (HADS anxiety and depression scores), comparing Alpha- and Delta-variant dominant waves.

Results: We analyzed 1,040 patients (median age, 57 [IQR 49–66] years; men, 66.2%). Of the respondents, 45.4% had at least one PCC symptom 1 year after infection. The common symptoms included dyspnea (20.7%), fatigue/malaise (17.6%), muscle weakness (15.4%), decrease in concentration (13.4%), and sleep disorder (13.3%), followed by brain fog (8.4%). Among patients with PCC, 14.0% had anxiety (HADS-Anxiety ≥11), and 18.6% had depression (HADS-Depression ≥11), with four times higher proportions than those without PCC; only small variations by age, sex, and waves were observed. Associated factors for PCC were age 40 years or over, women, severity of COVID-19 during hospitalization, ex-smokers who quit smoking before COVID-19 infection and being infected during the Delta-variant dominant wave.

Conclusion: The study described the prevalence of PCC, associated factors, and mental health of COVID-19 survivors hospitalized during the Alpha- and Delta-variant dominant waves in Japan. Further follow-up will be conducted to examine the longer-term impact of COVID-19 on PCC, complications, daily life, and socioeconomic status.

Background: Use of novel tobacco products, such as heated tobacco products, has recently increased as a result of being promoted less harmful alternatives to cigarettes. The impact of the coronavirus disease 2019 (COVID-19) pandemic on tobacco use may differ depending on the type of tobacco.

Methods: We longitudinally investigated changes in tobacco use over a 1-year period using internet-based and self-reported questionnaires among Japanese aged 15 to 79 years. The study was conducted from 2019 to 2021, with participants before the COVID-19 pandemic in February 2020 as the pre-pandemic group and participants after that as the pandemic group. Accounting for population bias, we used sampling probability weighting referring to the nationwide data. The association between cessation and the COVID-19 pandemic was evaluated separately for each type of tobacco using logistic regression analysis.

Results: After conducting sampling probability weighting, 1,920 were in the pre-pandemic group and 2,681 were in the pandemic group. More participants in the pandemic group than in the pre-pandemic group achieved cessation after 1 year (13.8% vs 10.2%, P < 0.001). Dual users were more likely to quit during the pandemic than pre-pandemic (adjusted odds ratio [aOR] 2.56, P < 0.001), whereas exclusive novel tobacco users were less likely to quit during the pandemic (aOR 0.66, P = 0.041). Tobacco cessation was more frequently achieved among those who had intended to quit at baseline survey among conventional tobacco users (aOR 1.77, P < 0.001) and dual users (aOR 2.52, P < 0.001); however, this trend was not observed among novel tobacco users (aOR 1.49, P = 0.090).

Conclusion: Conventional and novel tobacco use patterns varied in response to the COVID-19 pandemic.

Introduction: Relative or absolute safety of heated tobacco products (HTPs) remains unknown, while independent literature suggests that these products do not favor tobacco control. We conducted a comprehensive systematic review and meta-analysis to evaluate HTP usage patterns and the effect of HTP use on conventional tobacco smoking (use transitions).

Methods: We used Pubmed/MEDLINE, Embase, and the Cochrane Library to identify all articles published up to February 2022 on HTP use. For the present review, we included all representative cross-sectional studies dealing with HTP use, and all prospective cohort studies or cross-sectional studies on conventional tobacco smoking transitions due to HTP use. From 610 non-duplicate articles, 76 were eligible (71 cross-sectional and 5 prospective cohort studies).

Results: Compared with young adults, HTP use was less frequent among middle-aged (15 studies; pooled odds ratio [OR] 0.59; 95% confidence interval [CI], 0.48–0.74) and older adults (12 studies; OR 0.17; 95% CI, 0.07–0.38). HTP use was more frequent among former (6 studies; OR 2.73; 95% CI, 1.03–7.25) and current smokers (12 studies; OR 14.53; 95% CI, 6.34–33.31). Overall, 68.3% of HTP users were dual users (n = 26). Eight studies (including 5 cohorts) showed that HTP users were more likely than non-users to start conventional cigarette smoking (2 studies; OR 6.31; 95% CI, 4.13–9.65), whereas current cigarette smokers using HTPs were less likely to quit (4 studies; OR 0.84; 95% CI, 0.80–0.89).

Conclusion: We found that HTPs are specifically popular among young generations. More than two out of three HTP users are dual users. Prospective studies consistently show that, in real life, HTPs are not effective smoking-cessation tools.

Background: Spontaneous pregnancy loss (SPL) precedes an increased risk of reduced fertility, while its etiology mechanism remains largely unknown. Liver dysfunction presenting in early pregnancy may represent a pre-existing undiagnosed liver condition affecting fetal development. Here, we investigated whether maternal abnormal liver function in early pregnancy contributed to the incidence of SPL.

Methods: Data on pregnant women were leveraged from the Maternal Health Care Information System in Shanghai City from 2017 to 2021. Liver dysfunction status was defined as having any elevated liver function biomarker levels (LFBs) at the first antenatal visit. SPL cases were defined as fetal death occurring before 28 weeks gestation. Generalized linear models were used to estimate crude and adjusted risk ratios (RRs and aRRs, respectively) and 95% confidence intervals (CIs).

Results: Among 10,175 leveraged pregnant women, 918 (9.0%) SPL cases were recorded. Maternal liver dysfunction in early pregnancy was associated with a 49% increased risk of SPL (RR 1.49; 95% CI, 1.22–1.84). This positive association persisted after adjustment for covariates (aRR 1.55; 95% CI, 1.26–1.92). Higher γ-glutamyl transferase (GGT) and alkaline phosphatase (ALP) levels were also linked with increased risk of SPL in a linear fashion (aRRs per 1 standard deviation increase: 1.13; 95% CI, 1.08–1.17 and 1.13; 95% CI, 1.07–1.20, respectively). Similar magnitudes of associations were observed between normal weight and overweight pregnant women in subgroup analysis.

Conclusion: We provide new evidence that maternal abnormal liver function in early pregnancy, as well as GGT and ALP, predisposes to an increased risk of SPL.

Background: With global aging, especially in Asia, preventing pneumonia among seniors is vital. The necessity of introducing pneumococcal vaccines among the elderly has been highlighted, but there is a paucity of community-based real-world evidence on their effect. Sera Town in Hiroshima Prefecture, a super-aged community, launched a distinctive pneumococcal vaccination support project for elderly residents and conducted a 5-year follow-up survey. This study evaluates the effectiveness of this vaccination initiative.

Methods: From October 2010 to March 2015, Sera Town recruited elderly residents for PPSV23 vaccination with partial cost subsidies. Participants were surveyed annually for 5 years post-vaccination to assess pneumonia incidence, calculated on a person-years basis. Using vital statistics from 2000 to 2016, we quantified changes in mortality rates associated with the vaccination support project through an interrupted-time-series analysis.

Results: Of approximately 7,900 residents aged 65 and older, 3,422 (43%) participated in the project (median age: 84 years; range: 70–114 years; 56.7% female). Over 14,559 person-years of observation, 295 participants developed pneumonia. The post-vaccination incidence rate was 20.3 per 1,000 person-years (95% confidence interval [CI], 18.0–22.7). Interrupted time series analysis indicated a 25% reduction in Sera Town’s pneumonia mortality rate post-project, reversing an annual increase of 0.23 per 1,000 population pre-project to an annual decrease of 0.04 per 1,000 population post-project.

Conclusion: This study provided real-world evidence on the association with PPSV23 vaccination on the general elderly through a community-based study. The results may be particularly useful for regions where PPSV23 serotypes are prevalent, offering insights for areas facing aging challenges.

Background: Japan’s stringent licensing policies for older drivers have not been questioned, possibly due to negative perceptions of older drivers potentially influenced by media coverage of their car crashes. We examined whether older drivers’ fatal crashes are over-represented in news articles.

Methods: To examine the news coverage of fatal crashes that occurred between January 2016 and December 2020, we extracted driver- and crash-related data from articles reporting fatal crashes in the two best-selling newspapers, Yomiuri and Asahi. We obtained the corresponding data of police-reported fatal crashes during the same period. We calculated the proportion of newspaper-reported fatal crashes to police-reported fatal crashes by at-fault driver’s age group and crash characteristics.

Results: Of 12,987 police-reported fatal crashes, 5,888 (45%) and 2,909 (22%) crashes were reported in Yomiuri and Asahi newspapers, respectively. Excluding 2,098 crashes where at-fault drivers or their ages were not identifiable, Yomiuri reported 39%, 35%, and 31%, and Asahi reported 20%, 16%, and 14% of fatal crashes caused by drivers aged <30 years, 30–69 years, and 70 years or older, respectively. Crashes that caused more fatalities or killed children tended to be reported regardless of at-fault drivers’ age groups. Compared with young and middle-aged drivers, older drivers’ fatal crashes involving child fatalities were more often reported, whereas their single fatal crashes ending in their own deaths were less often reported.

Conclusion: Older drivers’ at-fault fatal crashes were not over-represented in the news coverage of overall fatal crashes, and their crashes killing themselves were under-reported.

Background: The interaction and substitution effects of physical activity (PA) and sitting time (ST) living in non-western countries have not been well investigated. This study aimed to examine the association of moderate-to-vigorous physical activity (MVPA) and ST with disability and mortality in older adults.

Methods: This prospective study analyzed data from 10,164 adults over 65 who participated in the Kyoto-Kameoka study in Japan. We evaluated MVPA and ST using the validated International Physical Activity Questionnaire-Short Form. Participants were categorized into four groups based on their levels of MVPA (150 min/week) and ST (300 min/day): low MVPA/high ST, low MVPA/low ST, high MVPA/high ST, and high MVPA/low ST. Outcomes were gathered between July 30, 2011, and November 30, 2016.

Results: Over a median follow-up of 5.3 years (45,461 person-years), 2,273 disability cases were documented. The low MVPA/high ST groups were associated with higher disability risk than those in the high MVPA/low ST groups (hazard ratios [HRs], 1.52; 95% confidence interval [CI], 1.31–1.75), and the interaction between MVPA and ST accounted for 48.5% of the relative excess risk of disability in the low MVPA/high ST group (p for interaction = 0.006). Replacing daily 10 min of ST with 10 min of MVPA was associated with a reduced risk of disability (HR, 0.980; 95% CI, 0.971–0.989) and all-cause mortality (HR, 0.975; 95% CI, 0.962–0.988).

Conclusions: These findings indicate that even a small substitution of ST with MVPA could help lower both the risk of disability and mortality.

Background: Poor dietary habits are a significant changeable factor contributing to negative health effects; however, the connection between variations in dietary diversity over time and mortality remains uncertain. This study aimed to evaluate the association between longitudinal changes in the dietary diversity score (DDS) and mortality in Japanese adults.

Methods: This prospective study included 20,863 adults (13,144 women, 7,719 men) aged 40-79 years from the Japan Collaborative Cohort Study. The DDS was evaluated twice, once at baseline and again 5 years later, using a validated food frequency questionnaire that assessed 33 food items. Participants were classified into four groups based on mean DDS: baseline low DDS/5 years later low DDS (n=7,866; Low/Low group), baseline low DDS/5 years later high DDS (n=2,951; Low/High group), baseline high DDS/5 years later low DDS (n=3,000; High/Low group), and baseline high DDS/5 years later high DDS (n=7,046; High/High group). Survival data were collected until 2009, and hazard ratios (HRs) for mortality were calculated using a Cox proportional hazards model.

Results: During a median follow-up of 14.8 years (256,277 person-years), 2,995 deaths were documented. After adjusting for confounders, participants in the High/High group had a lower HR for mortality from all causes (HR:0.82; 95% confidence interval [CI]:0.74–0.91) and cardiovascular disease (HR:0.81; 95% CI:0.67–0.98) than those in the Low/Low group. Similar associations were observed with dairy, soy, and vegetables/fruits, but they were validated exclusively in women.

Conclusions: This study showed that maintaining a higher DDS may be associated with lower mortality in women.

Background: Informal caregiving of older parents adversely affects the mental health of family caregivers. However, the psychological effects of caregiving cessation and the trajectories of these effects have rarely been examined in Japan. This study addresses this gap.

Methods: Based on a 17-wave nationwide population-based survey in Japan, we analyzed longitudinal data from 8,280 individuals aged 50–59 years in 2005 who started caring for their older parents in 2006 or later and ceased caregiving by 2021. We identified the timings of caregiving onset and cessation and examined the trajectory of psychological distress (PD), defined as a Kessler score ≥5 on the 6-item Kessler scale (range 0–24). Linear mixed models were used to assess the trajectory of PD that evolved after caregiving cessation over the subsequent 3 years.

Results: After adjusting for covariates, the probability of PD decreased by 5.6 percentage points (from 40.8%; 95% confidence interval [CI], 4.1–7.0%) for female caregivers and by 1.9 percentage points (from 31.7%; 95% CI, 0.3–3.5%) for male caregivers at caregiving cessation, remaining stable in subsequent years. For women, higher PD risks related to co-residence with a care recipient diminished quickly upon cessation of caregiving, while the unfavorable impacts of no social activity, extended duration of care, and long-hour daily care persisted in subsequent years. For male caregivers, the impact was generally more limited.

Conclusion: These results suggest that changes in mental health following caregiving cessation warrant serious consideration when developing support programs for former family caregivers.

Background: As the most common chronic liver disease worldwide, the natural history of metabolic dysfunction-associated steatotic liver disease (MASLD) in the general population is barely reported.

Methods: The Shanghai Suburban Adult Cohort and Biobank study recruited 36,404 adults between 2016 and 2017, and followed up 25,085 participants between 2019 and 2023 in Songjiang District. A questionnaire survey was conducted using face-to-face interview, and physical examination and laboratory tests were conducted. MASLD was diagnosed using liver ultrasound and the cardiometabolic risk factors (CMRF).

Results: A total of 36,122 and 21,831 participants met the criteria for baseline and follow-up analyses. The prevalence of MASLD at baseline was 36.8% overall, and 73.6% among those with a body mass index (BMI) over 28 kg/m². After a median follow-up time of 4.26 years, the incidence density for MASLD was 8.4, and the recovery density was 11.4 per 100 person-years overall and was 20.0 and 8.4 per 100 person-years for those with baseline BMI over 28 kg/m². Per 1 kg/m² increase in baseline BMI was associated with a 15% increase in incidence (hazard ratio [HR] 1.15; 95% confidence interval [CI], 1.14–1.17) and an 8% decrease in recovery (HR 0.92; 95% CI, 0.90–0.93). From baseline to follow-up visit, participants who remained non-obese or remained normal cardiometabolic status always showed the lowest incidence and the highest recovery rate, followed by those with improved status.

Conclusion: The prevalence and incidence of MASLD were high among Shanghai residents, and active recovery was also observed. Obesity was the most important risk factor, and weight loss and lipid level reduction were beneficial for preventing or reversing MASLD.

In epidemiological or clinical studies with follow-ups, data tables generated and processed for statistical analysis are often of the “wide-format” type, consisting of one row per individual. However, depending on the situation and purpose of the study, they may need to be transformed into the “long-format” type, which allows for multiple rows per individual. This tutorial clarifies the typical situations wherein researchers are recommended to split follow-up times to generate long-format data tables. In such applications, the major analytical aims consist of (i) estimating the outcome incidence rates or their ratios between ≥2 groups, according to specific follow-up time periods; (ii) examining the interaction between the exposure status and follow-up time to assess the proportional hazards assumption in Cox models; (iii) dealing with time-varying exposures for descriptive or predictive purposes; (iv) estimating the causal effects of time-varying exposures while adjusting for time-varying confounders that may be affected by past exposures; and (v) comparing different time periods within the same individual in self-controlled case-series analyses. This tutorial also discusses how to split follow-up times according to their purposes in practical settings, providing example codes in Stata, R, and SAS.

Background: Coronavirus disease 2019 (COVID-19) in children is often asymptomatic, posing challenges in detecting infections. Additionally, factors contributing to infection remain poorly understood. This study aimed to investigate trends in anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid antibody seroprevalence, the relationship between seroprevalence and parental perception of child infection, and factors related to COVID-19 in children.

Methods: In December 2020, 355 children aged 6–12 years in one elementary school were enrolled in the study. The anti-SARS-CoV-2 nucleocapsid antibody seroprevalence was assessed, and questionnaires were administered annually for 3 years. Parents’ perceptions of infection and factors contributing to infection were examined.

Results: The seroprevalence was 0.6%, 2.2%, and 60.9% in the first, second, and third years, respectively. The third-year seroprevalence among children reported as ‘infected,’ ‘not tested but had symptoms,’ and ‘not infected’ by parents was 97.3%, 83.3%, and 35.7%, respectively. Increased odds of seropositivity at the third-year measurement were observed in lower grades (adjusted odds ratio [aOR] 2.79 compared with higher grades) and in children more likely to play with others (aOR 3.97 for ‘somewhat’ and aOR 2.84 for ‘often,’ compared with ‘rarely’). No significant associations with seropositivity were found for sex, siblings, body mass index, serum 25-OH vitamin D₃ concentration, or sleep duration.

Conclusion: The Omicron variant outbreak from the end of 2021 led to a sharp increase in seroprevalence among children, with many unaware of their infection. Frequent play with others may facilitate transmission in children. These data provide useful information for developing countermeasures against COVID-19 and other future pandemics.

Background: This study investigated fundamental demographic variables within the Taiwan Biobank (TWBB) and compared them with national demographic statistics. Additionally, a matched cohort analysis compared TWBB participants with nonparticipants to uncover disparities in sociodemographic and clinical characteristics.

Methods: A total of 128,663 individuals aged 30 to 70 years without cancer were recruited within the TWBB, and 514,652 nonparticipants matched by age and sex were randomly selected from the National Health Insurance claims database. Sociodemographic variables, healthcare utilization metrics, underlying medical conditions, and subsequent mortality and cancer risk were analyzed.

Results: TWBB participants were more likely to be female, older, married, higher educated, with higher incomes, and urban residency. Healthcare utilization metrics showed minimal differences. Pre-cohort entry, TWBB participants had a higher prevalence of certain medical conditions, such as peptic ulcer disease, osteoarthritis, osteoporosis, and uterine leiomyoma in females. During follow-up periods, elevated mortality rates were observed among TWBB participants but decreased cancer risk.

Conclusion: The TWBB cohort exhibits disparities in sociodemographic and health-related attributes compared to the general population, comprising participants who were older, female, married, higher educated, higher income, and predominantly resided in urban areas. While mortality rates are slightly elevated within the TWBB cohort, cancer incidence rates are lower. Despite limitations in representativeness, the TWBB’s size and exposure measures offer valuable insights into associations between exposures and health conditions.

Background: While evidence from Western countries links low-to-moderate alcohol consumption to a lower risk of type 2 diabetes mellitus (T2D), findings have been inconsistent in Asia. Since T2D in Asia involves both insulin resistance and deficient insulin secretion, both of which are differently affected by alcohol, we prospectively examined whether the association differs according to body mass index (BMI) categories among the Japanese.

Methods: Participants were 31,524 health checkup examinees (26,819 males and 4,705 females aged 20-64 years) who were free from diabetes at baseline. Self-reported data on alcohol use were used to estimate the average daily alcohol consumption at the baseline. Incident diabetes was identified at annual checkups during the follow-up period. A Cox proportional hazards model was used to estimate hazard ratios and 95% confidence intervals.

Results: During a median follow-up of 12.0 years, 3,527 male and 287 female participants developed T2D. The association between alcohol consumption and T2D risk differed markedly by BMI in both sexes. Among males, low- and moderate-level alcohol consumption was associated with a lower T2D risk in individuals with BMI ≥25.0 kg/m², whereas consumption at a level of 2 go/day (approximately 46 g ethanol) was linked to an increased T2D risk in those with BMI ≤22.0 kg/m². In females, similar patterns were observed, although confidence intervals were broad due to smaller sample size.

Conclusions: In Japan, low-to-moderate alcohol consumption may lower T2D risk in those with excess body weight, while high alcohol consumption may increase T2D risk in those with lower BMI.

Background: Although both a lower and a higher body mass index (BMI) are reportedly associated with head and neck cancer (HNC), reports from Asia are scarce. Moreover, evidence regarding the association between height and HNC is limited.

Methods: We investigated associations between BMI, height, and the incidence of HNC among 102,668 participants (49,029 men and 53,639 women) aged 40–69 years in the Japan Public Health Center-based Prospective Study. We followed participants from 1990 to 2013. We conducted a Cox proportional hazards regression analysis, which included adjustment for potential confounders, such as smoking status. Baseline weight and height information were self-reported.

Results: Over an average follow-up of 18.7 years, 311 HNC cases were newly diagnosed. Lower BMI was significantly associated with HNC, with hazard ratios (HR) of 2.75 (95% confidence interval [CI], 1.63–4.64) for <18.5 kg/m² and 1.63 (95% CI, 1.15–2.30) for 18.5–20.9 kg/m² compared to 23–24.9 kg/m². Increased risk was suggested for higher BMI, with an HR of 1.30 (95% CI, 0.84–2.00) for ≥27.5 kg/m². This trend was also observed in quadratic models. Results were similar among never-smokers. Meanwhile, only lower BMI showed a strong association with HNC risk among former and current smokers (HR 3.09; 95% CI, 1.54–6.20 for <18.5 kg/m² compared to 23–24.9 kg/m²). Height showed no association with HNC.

Conclusion: Lower BMI was significantly associated with HNC risk, while increased HNC risk was suggested in higher BMI among never-smokers. Among former and current smokers, only lower BMI was associated with HNC risk.

Background: Parents’ educational background is presumed to influence the incidence of vaccine-preventable diseases in children through their decisions about vaccinations and other family lifestyle choices. Regarding voluntary vaccination, a household’s economic situation may also be associated with non-vaccination. Therefore, this study investigated the association between parental education and vaccine-preventable diseases (varicella, mumps, influenza [flu], pertussis, measles, and rubella) in children, which currently remains elusive.

Methods: We used datasets from the Japan Environment and Children’s Study, which included 104,062 fetal records; our study population comprised 80,930 children up to the age of 3 years. The associations between parental educational background and children’s infectious diseases were examined using binomial logistic regression analysis. The mediating effects of household income, vaccination, and smoking were examined using a path analysis.

Results: For varicella, mumps, and influenza covered by voluntary vaccination, a higher education level of the father was associated with a lower incidence of infection. The association between mothers’ education and children’s infection was limited. There were both income-mediated and non-income-mediated pathways between parental education and voluntary vaccination. For pertussis, measles, and rubella, which are covered by routine vaccines, there was no association between parental education and the child’s infection.

Conclusion: An association between parental education and childhood infections was observed. Providing financial support for vaccination and communicating the benefits of vaccination in a way that parents at all levels of education can understand may help reduce the incidence of infectious diseases among children.

Background: Several studies reported an association between the number of teeth and the incidence of hip fractures in observational studies, mainly in middle-aged adults. This retrospective cohort study aimed to clarify the association between the number of teeth and the incidence of hip fractures.

Methods: In this retrospective cohort study, a total of 256,772 participants aged 75 years or older who underwent public dental checkups in Japan were evaluated. Exposure in this study was the number of teeth, with a maximum number of 28, excluding third molars. Outcome measures were the incidence of hip fractures needing surgery, using the Japanese procedure codes in medical claims.

Results: A total of 190,998 participants met the inclusion criteria and were available for analysis. Adjusted Fine and Gray models identified a significant association between the number of teeth, including sound, filled, and decayed teeth, and the incidence of hip fractures among women but not for men. The continuous net reclassification improvement (NRI) of the sound and filled teeth count model increased by 0.078 compared with that of the sound, filled, and decayed teeth count model among women.

Conclusions: The number of sound and filled teeth predicted the risk of hip fractures in women, whereas no association was observed between the number of teeth and hip fractures in men.

Background

Studies have shown that informal caregiving is associated with an increased risk of cardiovascular diseases. However, there is limited evidence on the mechanisms involved. To fill this knowledge gap, we investigated the association of informal caregiving with changes in health-related behaviors.

Methods

We analyzed a nationally representative sample aged 50–59 years as of 2005 using fifteen waves of the Longitudinal Survey of Middle-Aged and Older Adults, conducted between 2005–2019. We investigated the association between the change in informal caregiving status and the change in health-related behaviors, including (1) heavy drinking, (2) smoking, (3) no exercise habits, and (4) no attendance at annual health checkups. We used multivariable logistic regression models with correlated random effects, adjusting for individual-level time-invariant characteristics.

Results

Among 268,165 observations from 30,530 participants (median age 55 [interquartile range 52–57] at baseline; 51.6% women), 32,164 (12.0%) observations from 10,224 individuals provided informal care. After adjusting for potential confounders, informal caregiving was associated with higher probabilities of deteriorating health-related behaviors, including heavy drinking (adjusted odds ratio [aOR] 1.16; 95% confidence interval [CI] 1.03–1.32; adjusted p=0.032) and no exercise habits (aOR 1.09; 95%CI 1.04–1.15; adjusted p<0.001). We observed similar patterns for smoking (aOR 1.12; 95%CI 1.001–1.26; adjusted p=0.053) and no attendance at health checkups (aOR 1.05; 95%CI 0.999–1.10; adjusted p=0.053).

Conclusion

This study showed that the transition into informal caregiving was associated with deteriorating cardiovascular-related health behaviors in Japan. These findings highlighted the importance of continued efforts to prevent the deterioration of caregivers’ health-related behaviors.

Background: We launched the Wako Cohort Study in 2023 to identify individual and socio-environmental factors related to the extension of healthy life expectancy and the reduction of health disparities among community-dwelling adults and to develop health promotion and care prevention strategies. This study profile aims to describe the study design and participants’ profile at baseline.

Methods: The Wako Cohort Study is a prospective study of community-dwelling adults aged ≥ 40 years living in Wako City, Saitama Prefecture, Japan. The Wako Cohort Study consists of two surveys: a mail-in survey for persons aged ≥ 40 years and a face-to-face assessment (on-site survey) for those aged ≥ 65 years. The survey items were designed considering the following points: 1) life course perspective (transition from middle to old age in the life course), 2) health indifference, and 3) employment in older age.

Results: A total of 8,824 individuals participated in the mail-in survey (2,395 persons aged 40–64 years and 6,429 aged ≥ 65 years). Of those aged ≥ 65 years who returned the mail survey, 1,004 participated in the subsequent on-site survey. Men aged ≥ 65 years tended to have higher health interests than those aged 40–64 years; however, this was not true for women. In the mail-in survey, 30.4 % of those aged ≥ 65 years were employed.

Conclusions: The Wako Cohort Study is expected to provide new insights into the development of strategies to extend healthy life expectancy and reduce health disparities in Japan.

Background: Healthy life expectancy (HLE) is a population health indicator that is widely used in developed countries, but little is known about its relationships with combinations of non-communicable disease risk factors. This study was conducted to examine HLE at age 65 according to combinations of blood pressure levels, body mass index, smoking status, and diabetes mellitus (DM) in a Japanese population.

Methods: In a nationwide cohort study (NIPPON DATA90), data on these risk factors were obtained from participants in 1990 through physical examinations, blood tests, interviews, and questionnaires. Subsequently, participants aged ≥65 years underwent surveys on activities of daily living in 1995 and 2000, and multistate life tables were used to calculate combination-specific HLEs and their 95% confidence intervals (CIs).

Results: The study population comprised 6,569 participants (men: 2,797; women: 3,772) who were followed-up until 2010. HLE at age 65 in men with grade II/III hypertension, obesity, current smoker status, and DM (HLE: 12.9 years, 95% CIs: 12.9-13.0 years) was 9.7 years shorter than men without these risk factors (HLE: 22.6 years, 95% CIs: 22.4-22.8 years). Similarly, HLE at age 65 in women with grade II/III hypertension, obesity, current smoker status, and DM (HLE: 16.2 years, 95% CIs: 15.9-16.5 years) was 10.1 years shorter than women without these risk factors (HLE: 26.3 years, 95% CIs: 26.3-26.3 years).

Conclusion: The large discrepancies in HLEs underscore the impact of non-communicable disease risk factors, which should be considered when formulating health interventions to improve HLE in Japanese older adults.

Background: There is still uncertainty regarding the association between maternal serum levels of retinol-binding protein 4 (RBP4) and pregnancy outcomes. This study aimed to determine the association between RBP4 levels and incidence of small/large for gestational age (SGA/LGA) infants among the Chinese population.

Methods: This was a retrospective study of 11,854 pregnant women who delivered at Changzhou Maternal and Child Health Care Hospital between 2016 and 2017 and whose serum RBP4 levels were measured at the time of admission. The incidence of SGA/LGA deliveries was retrieved from the medical records of the participants.

Results: Maternal RBP4 levels in the second, third and fourth quartiles (28.8–34.0, 34.1–40.0, and >40.0 mg/L, respectively) were associated with lower birthweights relative to those in the first quartile (<28.8 mg/L), with estimated average decreases of 51.30 g (95% CI: -70.51, -32.10), 86.86 g (95% CI: -106.50, -67.22) and 124.08 g (95% CI: -144.51, -103.64), respectively (P for trend <0.01). Pregnant women in the fourth quartile for RBP4 levels had a greater SGA risk (OR: 2.14, 95% CI: 1.72, 2.65) and lower LGA risk (OR: 0.53, 95% CI: 0.45, 0.63) than those in the first quartile after controlling for demographic variables, gestational age, pregnancy complications and other laboratory results. The sensitivity analysis indicated the consistency of these findings.

Conclusion: High RBP4 levels in late pregnancy are associated with an increased SGA risk and decreased LGA risk, indicating that serum RBP4 levels at the time of admission for delivery could be a promising predictor of SGA/LGA delivery.

Background: Community social capital is associated with various health outcomes; however, its impact on mortality is not fully understood, particularly in non-Western settings. This study examined the association between community-level social capital and all-cause mortality among community-dwelling older Japanese adults.

Methods: The baseline data were obtained from a 2015 questionnaire survey for all 132,005 residents aged ≥65 years without long-term care insurance certification in Adachi Ward (consisting of 262 small districts) of the Tokyo metropolitan area. We measured two aspects of social capital: neighborhood cohesion as cognitive social capital and neighborhood network as structural social capital. For district-level social capital, we aggregated the individual responses of neighborhood cohesion and neighborhood network in each district.

Results: A total of 75,338 were analyzed. A multilevel survival analysis with an average follow-up of 1,656 days showed that higher district-level neighborhood cohesion was associated with a lower risk of all-cause mortality in men (hazard ratio [95% confidence interval]: 0.92 [0.84–0.99] for the highest quintile and 0.91 [0.82–0.99] for the second, compared to the lowest), not in women. This association was more pronounced in men aged 65–74 years.

Conclusions: This study provides valuable insights from the Asian population. Men, who typically have fewer social networks and support systems than women, could receive more benefits from residing in a cohesive community, which may contribute to their longevity. These findings support public health strategies that bolster community social capital as a means of archiving longevity among older men, underscoring the importance of social integration in aging societies.

Background: The Tohoku Medical Megabank Project has initiated the Birth and Three-Generation Cohort Study (TMM BirThree Cohort Study) including genomic and omics investigations, and conducted a self-administered food frequency questionnaire with the response option “constitutionally unable to eat or drink it” for individual food items (TMM-FFQ) for pregnant women. This study evaluated the validity of the TMM-FFQ among pregnant women.

Methods: Participants comprised 122 pregnant women aged ≥20 years residing in Miyagi Prefecture who completed weighed food records (WFRs) for 3 days as reference intake and the TMM-FFQ during mid-pregnancy. Correlations between nutrient or food group intakes based on the WFR and the TMM-FFQ were calculated using Spearman’s rank correlation coefficients (CCs), adjusting for energy intake and correcting for random within-individual variation of WFR. Cross-classification was also conducted according to quintiles using the WFR and TMM-FFQ data.

Results: The percentages of participants who chose the “constitutionally unable to eat or drink it” option were >3% for seven food and drink items. CCs were >0.30 for 31 nutrients; the median across energy and 44 nutrients was 0.41. CCs were >0.30 for 14 food groups; the median across 20 food groups was 0.35. The median percentages of cross-classification into exact plus adjacent quintiles and extreme quintiles were 63.1% and 3.3% for energy and nutrients and 61.9% and 4.1% for food groups, respectively.

Conclusions: The validity of the TMM-FFQ compared with the WFR was reasonable for certain nutrients and food groups among pregnant women in the TMM BirThree Cohort Study.

Background: The fecal immunochemical test (FIT) has been widely used in colorectal cancer (CRC) screening, yet the practical performance of FIT combined with questionnaire-based risk assessment (QRA) remains undetermined. Moreover, risk factors for distinct CRC precursors identified in screening have been rarely compared.

Methods: This study was based on a population-based CRC screening in China, with 2,120,340 participants completing both FIT and QRA. Those with positive FIT or high QRA scores were recommended for colonoscopy. We reported the compliance, detection rate, and colonoscopy workload according to FIT and QRA results. We also explored risk factors for conventional adenomas and serrated polyps.

Results: The compliance rate of colonoscopy in the subgroup of FIT (+) and QRA (+) was 41.4%, higher than the rates in FIT (+) and QRA (-), as well as FIT (-) and QRA (+), which were 38.7% (P<0.001) and 16.4% (P<0.001), respectively. The corresponding detection rates of advanced neoplasia were 18.2%, 13.2%, and 9.3% (all P <0.001), respectively. Moreover, the required numbers of colonoscopies to detect one advanced neoplasia in the three subgroups were 5.5, 7.6, and 10.8, respectively. Increased body mass index, smoking, alcohol consumption, red meat intake, and type 2 diabetes were associated with higher risk of advanced adenomas and advanced serrated polyps, whereas vegetable intake was inversely associated advanced adenomas.

Conclusion: FIT and QRA can synergistically identify individuals at high risk of colorectal advanced neoplasia, with those testing positive for both deserving immediate attention. Modifiable factors were identified to complement screening for preventing CRC precursors.

Background: Few have examined the condition of subjective daytime sleepiness in workers and its relation to their work productivity. This study aimed to clarify the association between the presence of subjective daytime sleepiness and work productivity measures, including presenteeism and absenteeism, as well as factors related to the presence of the symptom in daytime workers.

Methods: This cross-sectional study included 17963 daytime workers who attended the annual medical check-up. They were categorized into four groups; the daytime sleepiness group was defined as having only subjective daytime sleepiness, the insomnia group as having only insomnia symptoms, the combination group as having both subjective daytime sleepiness and insomnia symptoms, and the healthy group as having no sleep complaints. This study used demographics, health status, workplace, work productivity, and sleep items included in the self-reported medical check-up questionnaire.

Results: The combination group had significantly worse presenteeism than other groups. The daytime sleepiness and insomnia groups had significantly worse presenteeism than the healthy group. The results of absenteeism were the same as presenteeism. Factors related to the positivity for subjective daytime sleepiness were presence of psychiatric disease, the positivity for habitual snoring and/or witnessed apnea, shorter sleep duration on workdays, long working hours, female sex, living alone, the amount of social jetlag, and younger age.

Conclusions: Subjective daytime sleepiness, not just insomnia symptoms, has a significant negative impact on work productivity, and both workplace and individual approaches should not be ignored for addressing subjective daytime sleepiness among daytime workers.