Background: The association between decline in handgrip strength from midlife to late-life and dementia is unclear.

Methods: Japanese community-dwellers without dementia aged 60 to 79 (i.e., individuals in late-life; mean age, 68 years) were followed for 24 years (1988–2012) (n=1,055); 835 of them had participated in a health examination in 1973–1974 (mean age, 53 years), and these earlier data were used for the midlife analysis. Using a Cox proportional hazards model, we estimated the risk conferred by a decline in handgrip strength over a 15-year period (1973-74 to 1988) from midlife to late-life on the development of total dementia, Alzheimer’s disease (AD) and vascular dementia (VaD) over the late-life follow-up period from 1988 to 2012.

Results: During the follow-up, 368 subjects experienced total dementia. The age- and sex-adjusted incidence of total dementia increased significantly with greater decline in handgrip strength (increased or unchanged handgrip strength [≥+0%] 25.1, mildly decreased [-14 to -1%] 28.4, and severely decreased [≤-15%] 38.9 per 1,000 person-years). A greater decline in handgrip strength was significantly associated with higher risk of total dementia after adjusting for potential confounding factors; subjects with severely decreased handgrip strength had 1.51-fold (95% confidence interval=1.14-1.99, p<0.01) increased risk of total dementia compared to those with increased or unchanged handgrip strength. Similar significant findings were observed for AD, but not for VaD.

Conclusions: Our findings suggest that a greater decline in handgrip strength from midlife to late-life is an important indicator for late-life onset of dementia.

Background: Considering the rate of growth of the older population in several countries, accidental falls in older cyclists are expected to increase. However, the prevalence and correlates of bicycle-related falls (BR-falls) are unknown. The aim of the present study was to explore the characteristics of BR-falls, focusing on the risk factors.

Methods: Seven-hundred and ninety-one older adults participated in a comprehensive baseline assessment including questions on bicycle use, BR-falls, lifestyle, and physical and cognitive evaluations. A cyclist was defined as a person who cycled at least a few times per month. The incidence of BR-falls in participants who did not report BR-falls at baseline was again ascertained three years later. Logistic regression analyses examined the predictors of BR-falls incidence.

Results: At baseline, 395 older adults were cyclist and 45 (11.4%) of them had experienced BR-falls. Adjusted regression analysis showed that slower gait velocity, shorter one-leg standing time, and experience of falls (i.e., non-BR-falls) were associated with BR-falls. Among the 214 cyclists who did not report BR-falls at baseline and who participated in both baseline and follow-up assessments, 35 (16.4%) cyclists experienced BR-falls during the 3-year follow-up. Adjusted regression analysis revealed that higher body mass index and non-BR-falls were predictors of future incident of BR-falls, independent of physical function.

Conclusions: Our results showed that experience of falls, irrespective of bicycling, is an independent correlate and risk factor of BR-falls. This suggests that experience of falls and BR-falls may share the same risk factors.

Background: This study aimed to examine the contextual effects of community-level social capital on the onset of depressive symptoms using a longitudinal study design.

Methods: We used questionnaire data from the 2010 and 2013 waves of the Japan Gerontological Evaluation Study that included 14,465 men and 14,600 women aged over 65 years from 295 communities. We also used data of a three-wave panel (2006–2010–2013) to test the robustness of the findings (n = 7,424). Using sex-stratified multilevel logistic regression, we investigated the lagged associations between three scales of baseline community social capital and the development of depressive symptoms.

Results: Community civic participation was inversely associated with the onset of depressive symptoms (men: adjusted odds ratio [AOR] 0.93; 95% confidence interval [CI], 0.88–0.99 and women: AOR 0.94; 95% CI, 0.88–0.997 per 1 standard deviation unit change in the score), while no such association was found in relation to the other two scales on social cohesion and reciprocity. This association was attenuated by the adjustment of individual responses to the civic participation component. Individual-level scores corresponding to all three community social capital components were significantly associated with lower risks for depressive symptoms. The results using the three-wave data set showed statistically less clear but similar associations.

Conclusions: Promoting environment and services enhancing to community group participation might help mitigate the impact of late-life depression in an aging society.

Background: In the present study, we examined the trends of premature mortality due to kidney and bladder cancers among the Japanese population from 1980 through 2010.

Methods: Mortality data were obtained from the World Health Organization mortality database. Years of life lost (YLL) was estimated using Japanese life tables. Average lifespan shortened (ALSS) was calculated and defined as the ratio of years of life lost relative to the expected lifespan.

Results: Over the study period, the age-standardized rates to the World Standard Population for deaths from kidney and bladder cancers were stable. The average years of life lost (AYLL) measure shows decreases of about four and six years of life for kidney cancer in men and women respectively, and decreases of about two years of life for bladder cancer in both sexes. The ALSS shows that patients with kidney cancer lost 21.0% and 24.7% of their lifespan among men and women in 1980, whereas respective losses were 15.3% and 15.8% in 2010. Also, patients with bladder cancer on average lost 13.5% in men and 14.2% in women in 1980 and 10.8% in men and 11.1% in women in 2010.

Conclusions: Our study shows favorable trends in premature mortality for kidney and bladder cancers in Japan over a 30-year period; however, patients with bladder cancer on average lost a smaller proportion of their lifespan compared to those with kidney cancer. The development of a novel ALSS measure is convenient in examination of the burden of premature mortality over time.

Background: Studies on sex-specific socioeconomic gradients in objectively evaluated diabetes among older adults are scarce.

Methods: We used cross-sectional data of 9,893 adults aged 65 years and older in Aichi Prefecture without long-term care insurance from the Japan Gerontological Evaluation Study (JAGES) in 2010 (Response rate: 66.3%). We collected demographic, socioeconomic (income, years of education, and longest occupation) and behavioral information using a mail-in self-reported survey. Blood samples for the objectively evaluated diabetes and self-reported medical history were collected at annual municipal health checkups. Poisson regression analysis stratified by sex with multiple imputations was conducted to calculate prevalence ratio and 95% confidence interval.

Results: A clear income gradient in diabetes prevalence was observed among women, from 11.7% in the lowest income quartile (Q1) to 7.8% in the highest (Q4). Among men, the findings were 17.6% in Q1 to 15.1% in Q4. The prevalence ratios for diabetes with incomes Q1 to Q4 were 1.43 (95% confidence interval [CI], 1.07–1.90) for women and 1.16 (95% CI, 0.90–1.50) for men after adjusting for age and other socioeconomic factors. Even after adjusting for marital status, body mass index, other metabolic risk factors, and lifestyle factors, the income-based gradient remained among women. Education and occupation were not significantly associated with diabetes in the study population.

Conclusions: Only women showed an income-based gradient in diabetes. Monitoring income gradient in diabetes is important in public health actions, even in older populations. Future longitudinal and intervention studies should evaluate the causal link of income to diabetes onset, determine the mechanisms of the potential sex differences in the income/diabetes association, and identify ways to mitigate the income-based inequality.

Background: Although meals that combine a staple food, main dish, and side dish (balanced meals) are recommended in Japan, the health effects of such meals are unclear. We investigated the association of frequency of eating balanced meals with frailty among community-dwelling older Japanese.

Methods: We analyzed data from 912 persons aged 65 years or older who participated in the Hatoyama Cohort Study or Kusatsu Longitudinal Study. The frequency of eating two or more balanced meals daily was self-reported as ≤1 day/week, 2 or 3 days/week, 4 or 5 days/week, and daily. Frailty was defined as the presence of at least three, and pre-frailty as the presence of one or two, of the following criteria: weight loss, muscle weakness, exhaustion, slowness, and low physical activity. Adjusted logistic regression was used to study associations of frequency of balanced-meal consumption with frailty (prefrailty and frailty combined) and frailty criteria.

Results: Participants reporting a frequency of balanced-meal consumption of ≤2 or 3 days/week had a higher prevalence of frailty (odds ratio [OR], 1.79; 95% confidence interval [CI], 1.21–2.64) than did those reporting a frequency of daily. Lower frequency of balanced-meal consumption was also associated with higher prevalences of weight loss (OR, 4.10; 95% CI, 1.90–8.85), exhaustion (OR, 6.35; 95% CI, 2.49–16.17), and low physical activity (OR, 1.92; 95% CI, 1.22–3.01).

Conclusions: Our findings suggest that more frequent twice daily consumption of meals with a staple food, main dish, and side dish decreases the risks of prefrailty and frailty.

Background: Lung cancers are classified into small-cell lung cancer (SCLC) and non-small-cell lung cancer due to their different treatment and prognosis. Although many studies have reported the specific survival of SCLC patients treated at cancer hospitals, survival from population-based data has rarely been reported.

Methods: We analyzed survival of SCLC cases diagnosed from 1993 through 2006 from a population-based cancer registry of six prefectures. To assess trends in SCLC survival, we defined three periods that mirrored developments in SCLC treatment: period 1, 1993–1998; period 2, 1999–2001; and period 3, 2002–2006. Assessments were based on relative survival (RS), excess hazard, and conditional survival.

Results: A total of 10,911 SCLC patients were analyzed. Five-year RS among limited disease SCLC (LD-SCLC) in periods 1 to 3 was 16.8%, 21.1%, and 21.4%, respectively. Five-year RS among extensive disease SCLC (ED-SCLC) in periods 1 to 3 was 2.3%, 2.8%, and 2.7%, respectively. Improvement in 5-year RS in periods 2 and 3 compared with period 1 was significant among both LD- and ED-SCLC patients (all P < 0.001). Conditional 5-year RS of LD-SCLC increased from 21% at year 0 to 73% at year 5, while that of ED-SCLC was 3% at year 0 and 53% at year 5.

Conclusions: The prognosis of SCLC patients improved from 1999–2001 but plateaued in 2002–2006, after which no further significant improvement was seen. Continuous survey based on population-based data is helpful in monitoring the impact of developments in treatment.

Background: Some studies have indicated that female birth and multiple births were risk factors for nausea and vomiting during pregnancy (NVP). The results, however, were conflicting. Our study was conducted to evaluate the association of maternal NVP with fetal sex in singleton and twin pregnancies.

Methods: We used the data set from a birth cohort study, the Japan Environment and Children’s Study (JECS). In the self-administered questionnaire, participants were asked whether they experienced NVP prior to 12 gestational weeks. Main outcome measures were the presence of NVP and severity of NVP. We estimated the association of fetal sex and birth plurality with NVP using logistic regression analysis, followed by interaction analysis.

Results: Of 91,666 women, 75,828 (82.7%) experienced at least some symptoms of NVP and 10,159 (11.1%) experienced severe NVP. Women with female pregnancies and twin pregnancies had higher odds for the presence of NVP and severe NVP compared to women with male pregnancies and singleton pregnancies, respectively. Moreover, of mothers with twin pregnancies, higher odds for the presence of NVP and severe NVP were reported when one or both infants were female, compared to those in which both infants were male. There was no significant interaction between fetal sex and birth plurality.

Conclusions: Female sex birth and multiple births are risk factors for the presence of NVP, and especially for severe NVP without interaction. These findings suggest that a factor abundant in the female fetus associates with the severity of NVP.

Background: Severe pediatric cases of hand, foot, and mouth disease (HFMD), herpangina (HA), and associated complications caused by enterovirus 71 (EV71) infection have brought substantial public health impact in Asia. This study aimed to elucidate the epidemiology of these pediatric cases in Japan.

Methods: A nationwide survey was conducted using stratified random sampling of hospital pediatric departments. We estimated the number of inpatients with HFMD, HA, and associated complications between April 1 and September 30, 2010, during which EV71 was circulating predominantly. Factors associated with severe cases with ≥7 days of admission, sequelae, or outcome of death were analyzed using multivariate logistic regression.

Results: During the 6-month epidemic period, the number of pediatric inpatients aged <15 years was about 2,900 (estimated cumulative incidence of hospitalized cases: 17.0 per 100,000 population). Severe cases were significantly associated with younger age. Compared to patients ≥5 years of age, the odds ratios (ORs) for <1 year of age and 1 to <3 years of age were 5.74 (95% confidence interval [CI], 2.14–15.4) and 2.94 (95% CI, 1.02–8.51), respectively. Elevated ORs for hyperglycemia (plasma glucose level of ≥8.3 mmol/L) on admission (OR 3.60; 95% CI, 0.94–13.8) were also observed.

Conclusions: Disease burden of pediatric inpatients with HFMD, HA, and associated complications in Japan was described for the first time. During an EV71 epidemic, younger age and, suggestively, hyperglycemia may have been critical factors requiring more careful treatment.

Background: To investigate the optimal values of BMI for the lowest risk of all-cause death and whether the optimal BMI differs according to smoking status in large-scale pooled analysis of 13 Japanese cohorts.

Methods: Data from 179,987 participants of 13 well-qualified cohort studies conducted throughout Japan were used for our analysis. A cohort-stratified Cox proportional hazard model was used. P values for interactions were calculated based on the cross product of BMI and age, sex, or smoking status.

Results: In the entire study population, all-cause mortality risk were lowest when the BMI was 22.0–24.9 kg/m². This was also the case for selected healthy participants (never smoked, baseline total cholesterol level ≥4.1 mmol/L; the first 5 years of follow-up data were excluded). No effect modification of age, sex, or smoking status was observed. Regardless of their BMI, never smokers always had a lower all-cause mortality risk than did current smokers even with an ideal BMI in terms of mortality risk.

Conclusion: A BMI of 22–24.9 kg/m² correlated with the lowest risk of mortality, regardless of whether all participants or selected healthy participants were analyzed. The fact that smoking was more strongly associated with mortality than did obesity would emphasize the urgency for effective anti-smoking programs.

Background: Prolonged periods of sitting time can be adversely associated with older adults’ well-being and functional capacities. Understanding patterns and contexts of sedentary behaviors (SB) can inform approaches to prevention. This study examined Japanese older adults’ objectively-assessed patterns and reported domains of SB and their interrelationships.

Methods: Participants (n = 297; aged 65–84 years) of this cross-sectional study wore an accelerometer for 7 days and completed a survey. Five measures related to SB patterns were identified from the accelerometer data. SB from six domains, socio-demographics, and chronic conditions were identified from the survey data. Relative contributions of six domains to objectively-measured prolonged sedentary time (≥30 minutes) and the number of breaks were examined in a series of multivariate linear regressions. Covariates were socio-demographics, chronic conditions, and accelerometer wear time.

Results: On average, participants spent 8.8 hours a day sedentary (58% of accelerometer wear time), with 7.6 breaks per sedentary hour, and 3.7 hours a day through prolonged sedentary bouts (4.4 time/day). The proportions of time in the SB domains were 9.4% for car, 4.0% for public transport, 6.1% for work, 45.5% for television (TV) viewing, 9.8% for computer use, and 25.1% for other leisure. Domains of SB that contributed significantly to longer sedentary time through prolonged bouts were TV viewing and computer use. TV viewing was also associated with a lesser number of breaks.

Conclusions: For Japanese older adults, initiatives to address SB could focus on breaking-up prolonged periods of SB by encouraging more frequent breaks, especially during TV viewing.

Background: From around 2012, the use of automated equipment for fine particulate matter (PM_2.5) measurement with equivalence to a reference method has become popular nationwide in Japan. This enabled us to perform a national health effect assessment employing PM_2.5 concentrations based on the standardised measurement method. We evaluated the association between non-accidental mortality and short-term exposure to PM_2.5 and coarse particulate matter (PM), with the latter estimated as the difference between suspended particulate matter and PM_2.5, for the fiscal years 2012-2014.

Methods: This was a time-stratified case-crossover study in 100 highly-populated Japanese cities. Mortality data was obtained from the Ministry of Health, Labour and Welfare. City-specific estimates of PM-mortality association were calculated by applying a conditional logistic regression analysis, and combined with a random-effects meta-analysis.

Results: The respective averages of daily mean concentration were 14.6 μg/m³ for PM_2.5 and 6.4 μg/m³ for coarse PM. A 10 μg/m³ increase in PM_2.5 concentrations for the average of the day of death and the previous day was associated with an increase of 1.3% (95% confidence interval (CI), 0.9-1.6%) in total non-accidental mortality. For cause-specific mortality, PM_2.5 was positively associated with cardiovascular and respiratory mortality. After adjustment for PM_2.5, we observed a 1.4% (95% CI, 0.2-2.6%) increase in total mortality with a 10 μg/m³ increase in coarse PM.

Conclusion: The study revealed that short-term exposure to PM_2.5 had adverse effects on total non-accidental, cardiovascular, and respiratory mortality in Japan. Coarse PM exposure also increased the risk of total mortality.

Background: While bathing styles vary among countries, most Japanese people prefer tub bathing to showers and saunas. However, few studies have examined the relationship between tub bathing and health outcomes. Accordingly, in this prospective cohort study, we investigated the association between tub bathing frequency and the onset of functional disability among older people in Japan.

Methods: We used data from the Japan Gerontological Evaluation Study (JAGES). The baseline survey was conducted from August 2010 to January 2012 and enrolled 13,786 community-dwelling older people (6,482 men and 7,304 women) independent in activities of daily living. During a 3-year observation period, the onset of functional disability, identified by new certification for need of Long-Term Care Insurance, was recorded. Tub bathing frequencies in summer and winter at baseline were divided into 3 groups: low frequency (0-2 times/week), moderate frequency (3-6 times/week), and high frequency (≥ 7 times/week). We estimated the risks of functional disability in each group using a multivariate Cox proportional hazards model.

Results: Functional disability was observed in a total of 1,203 cases (8.7%). Compared with the low-frequency group and after adjustment for 14 potential confounders, the hazard ratios (95% confidence intervals) of the moderate- and high-frequency groups were 0.91 (0.75-1.10) and 0.72 (0.60-0.85) for summer and 0.90 (0.76-1.07) and 0.71 (0.60-0.84) for winter.

Conclusion: High tub bathing frequency is associated with lower onset of functional disability. Therefore, tub bathing might be beneficial for older people’s health.

Background: This study investigated the relationship between long-term body weight gain after maturity and the incidence of chronic kidney disease (CKD).

Methods: The participants were 303 men without a history of cardiovascular and cerebrovascular diseases, kidney dysfunction, or dialysis treatment. Their body weight gain after maturity was examined using a standardized self-administered questionnaire. The participants were divided into two groups based on the presence/absence of a body weight gain of ≥10 kg since 20 years of age.

Results: After a 6-year follow-up, the cumulative incidence of CKD was significantly higher in participants with a body weight gain of ≥10 kg than in participants without body weight a body weight gain of ≥10 kg since 20 years of age (log-rank test: P = 0.041). After adjusting for the age, body mass index, estimated glomerular filtration rate levels, smoking and drinking habits, and the presence of hypertension, dyslipidemia, and hyperglycemia at baseline, the normal body weight participants with a body weight gain of ≥10 kg since 20 years of age was significantly related to the incidence of CKD (hazard ratio 2.47; 95% confidence of interval, 1.02–6.01, P = 0.045).

Conclusions: These results suggest that long-term body weight gain after maturity in normal body weight participants may be associated with the incidence of CKD, independent of current body weight.

Background: Despite increasing evidence of an association between childhood socioeconomic disadvantage and cognitive outcomes, such as dementia and cognitive decline, in Western countries, there are no studies on this association from non-Western societies. We investigated the relationship between childhood socioeconomic status (SES) and subjective symptoms of dementia among community-dwelling older Japanese people and examined age and sex variations in this association.

Methods: Data were derived from a cross-sectional survey for all community-dwelling individuals aged 65 years and over in Adachi, Tokyo (n = 132,005). We assessed subjective dementia symptoms using a self-administered dementia checklist, which was validated by comparison with the Clinical Dementia Rating scale.

Results: Data from 75,358 questionnaires were analyzed. After adjusting for potential covariates, lower childhood SES was associated with greater likelihood of subjective dementia symptoms. We found a significant interaction between childhood SES and age on subjective dementia symptoms but no interaction between childhood SES and sex. Age-stratified analysis indicated that the association between lower childhood SES and subjective dementia symptoms was stronger in the ≥75 years subgroup than in the 65–74 years subgroup, indicating an effect modification of age on this association.

Conclusions: Our findings suggested that low SES in childhood might have a long-term influence on dementia symptoms in late life and that this influence varied by age. This differential association might be explained by the social and historical context in Japan (ie, World War II, postwar chaos, and high economic growth) that has shaped participants’ early experiences.

Background: The early life environment is now recognized as a key factor contributing to susceptibility to certain diseases in later life.

Methods: We initiated a cohort study among school children in 2011 to primarily investigate the associations between lifestyle and environmental factors and some surrogate markers of chronic diseases, such as cardiometabolic risk factors (ie, obesity, high blood pressure, high blood glucose, insulin, or lipids) and cancer risk factors (ie, height and age at menarche). A baseline questionnaire asked for information, including demographic variables, medical history and use of medication, dietary habits, physical activity, sleep habits, and behavioral and emotional problems of children. Follow-up surveys are planned for the fourth grade of elementary school and the first grade of junior high school. At these follow-up surveys, fasting blood samples will be obtained to measure cardiometabolic markers. We also checked the validity of a food frequency questionnaire, which was originally created for 6-year-olds but was modified for use in older children.

Results: A total of 3,141 first-year students at elementary schools in Hekinan City, Aichi Prefecture, participated in the study. The response rate was 87.4%. The means of age and body mass index were 6.99 (standard deviation, 0.28) years and 15.3 (standard deviation, 1.7) kg/m², respectively, in the 3,067 Japanese children (1,639 boys and 1,428 girls).

Conclusions: This cohort will reveal determinants of cardiometabolic risk factors and cancer risk factors during childhood.

Background: The lack of comprehensive food composition databases for sugar contents in Japanese foods has led to the lack of nutritional epidemiologic studies on sugar intake in Japanese population. This cross-sectional study aimed to investigate the association of free sugar intake estimated using a newly-developed food composition database with the characteristics and lifestyles of Japanese children aged 3-6 years.

Methods: The food composition database contained information on sugars in 2222 commonly consumed Japanese foods. Using this database, we estimated the sugar (total, added, and free sugars) intakes derived from a 3-day weighed dietary record of 166 boys and 166 girls aged 3-6 years living in 24 prefectures in Japan.

Results: The mean free sugar intake was 26.8 g/d (standard deviation (SD), 12.3 g/d), while the mean value for energy intake was 7.8% (SD, 3.2%). The prevalence of excessive free sugar intake (≥10% of energy intake) was 21.7%. Among the characteristics and lifestyles examined, screen time was most strongly associated with the prevalence of excessive free sugar intake: multivariate adjusted odds ratios (95% confidence intervals) for screen time <0.5, ≥0.5 to <1, and ≥1 h/d were 1.0 (reference), 3.81 (1.04, 13.98), and 4.36 (1.16, 16.35), respectively. Additionally, younger age, shorter sleep, and mothers with office work and service and sales jobs (compared with those with professional and managerial jobs) were significantly associated with a higher prevalence of excessive free sugar intake.

Conclusions: This study showed the sugar intake of Japanese children aged 3-6 years is positively associated with screen time.

Background: The Lung, hEart, sociAl, boDy (LEAD) Study (ClinicalTrials.gov; NCT01727518; http://clinicaltrials.gov) is a longitudinal, observational, population-based Austrian cohort that aims to investigate the relationship between genetic, environmental, social, developmental and ageing factors influencing respiratory health and comorbidities through life. The general working hypothesis of LEAD is the interaction of these genetic, environmental and socioeconomic factors influences lung development and ageing, the risk of occurrence of several non-communicable diseases (respiratory, cardiovascular, metabolic and neurologic), as well as their phenotypic (ie, clinical) presentation.

Methods: LEAD invited from 2011–2016 a random sample (stratified by age, gender, residential area) of Vienna inhabitants (urban cohort) and all the inhabitants of six villages from Lower Austria (rural cohort). Participants will be followed-up every four years. A number of investigations and measurements were obtained in each of the four domains of the study (Lung, hEart, sociAl, boDy) including data to screen for lung, cardiovascular and metabolic diseases, osteoporosis, and cognitive function. Blood and urine samples are stored in a biobank for future investigations.

Results: A total of 11.423 males (47.6%) and females (52.4%), aged 6–80 years have been included in the cohort. Compared to governmental statistics, the external validity of LEAD with respect to age, gender, citizenship, and smoking status was high.

Conclusions: In conclusion, the LEAD cohort has been established following high quality standards; it is representative of the Austrian population and offers a platform to understand lung development and ageing as a key mechanism of human health both in early and late adulthood.

Background: Some previous studies reported hearing ability can be reduced by impaired masticatory ability, but there has been little evidence reported of an association between hearing loss and unilateral mastication. Therefore, this study aimed to investigate the relationship between unilateral mastication (UM), estimated from individual functional tooth units (FTUs), and hearing loss in a representative sample of Korean adults.

Methods: The analyzed data were obtained from 1,773 adults aged 40–89 years who participated in Korean national survey. Hearing loss was defined as a pure-tone average of >25 dB at frequencies of 0.5, 1, 2, and 4 kHz in either ear. In each subject, UM was calculated as the difference in the sums of the FTU scores, which is an index of posterior tooth occlusion, on the two sides of the oral cavity. The scores were used to classify the UM into low, moderate, and high. The adjusted odds ratios (aORs) and their 95% confidence intervals (CIs) were calculated in multivariable logistic regression analyses.

Results: When controlling for sociodemographic factors, the aOR for hearing loss was 3.12 (95% CI, 1.21–8.03) for high UM relative to low UM. This association remained in a fully-adjusted model containing factors related to noise exposure (aOR 2.88; 95% CI, 1.12–7.46).

Conclusion: Adults with high UM as measured using FTUs showed a higher occurrence of hearing loss than those with low UM.

Background: Selection of test-negative controls takes less time and costs less than traditional control selection for evaluating vaccine effectiveness (VE). Here, rotavirus VE was evaluated using hospital controls and compared with test-negative controls to determine whether using the latter can substitute for the former.

Methods: We recorded gastroenteritis in children from 2 months to 2 years of age at six medical facilities in Saga City between January 4th and May 31st, 2014. Stools from all identified acute gastroenteritis patients were tested for rotavirus using immunochromatography. Rotavirus gastroenteritis (RVGE) cases had test-positive stool, whereas test-negative controls had gastroenteritis but no rotavirus infection; hospital controls were outpatients visiting the same facility for indications other than gastroenteritis. Vaccination status was verified by inspecting maternal and child health records, and demographic data were obtained from a questionnaire completed by the patients’ guardians or from the medical records. Unconditional logistic regression analysis was used to adjust for possible confounding factors.

Results: Sixty-four RVGE cases, 260 test-negative controls, and 589 hospital controls were enrolled. The characteristics of the two control groups, including RV vaccination history, were similar. The RVGE cases were more likely to have used daycare services than children from either of the two control groups. The VE against RVGE estimated using hospital controls was 86.6% (95% confidence interval [CI], 55.9–96.0%), very similar to the VE using test-negative controls (84.9% [95% CI, 49.6–95.5%]).

Conclusions: The estimated VE using test-negative controls and hospital controls is similar. Therefore, test-negative controls are considered appropriate for establishing VE.

Background: Although majority of survivors of the huge earthquake and tsunami evacuated to two types of temporary housings, prefabricated housing and rented housing, health effects of these different environments were unclear. We examined whether prevalent social participation in prefabricated housing brought larger health benefits than in rented housing using the largest health survey data of the disaster survivors.

Methods: This cross-sectional study used a 2012 survey by the Miyagi Prefectural Government in which almost all of evacuees were targeted (response rate = 61.6%). Self-rated health (SRH) and psychological distress measured by K6 score were the dependent variables, and social participation was the independent variable. Odds ratios of the social participation on health variables were estimated by logistic regression models. To assess the contribution of social participation, the population attributable fraction (PAF) was estimated.

Results: The participants lived in prefabricated and rented housing numbered 19,077 and 28,270, respectively. Participants in prefabricated housing had poorer SRH and K6 than those in rented housing. Social participation of prefabricated and rented housing were 38.2% and 15.4%, respectively. The absence of social participation was significantly associated with poor SRH and K6 among participants in both housing types. The PAFs of social participation with good SRH were 39.5% in prefabricated housing and 14.4% in rented housing. For K6, the PAFs were 47.1% and 19.5% in prefabricated and rented housing, respectively.

Conclusion: Compared to the residents in rented housing, residents in prefabricated housing had more frequent opportunities for social participation, which was associated with larger health benefits.

Background: In research using accelerometers to measure physical activity, the number of accelerometers that can be utilized in a study and the study duration are both constrained. It means that increasing the number of accelerometer wearing days for all subjects leads to a decrease in the total number of participants the study can recruit. We used simulations to find the optimal number of wearing days / number of participant combination given a fixed number of accelerometer days.

Methods: Two scenarios were studied here, including estimation of population physical activity level and the association between physical activity level and a health outcome. Another similar simulation was conducted by bootstrapping the National Health and Nutrition Examination Survey (NHANES) 2003-2006 accelerometer data (n=4,069).

Results: The simulation results of the first scenario showed that the error was minimized when the wearing day was one to two. Simulation results of the second scenario showed that the optimal number of wearing days increased with the total number of accelerometer days and decreased with intra-class correlation (ICC).

Conclusion: We developed a tool for researchers to determine the optimal combination of number of the accelerometer wearing days and the total number of participants, and showed that one to two accelerometer wearing day is optimal for estimation of population physical activity level.

Background: Low red blood cell folate concentrations during early pregnancy might cause neural tube defects. However, the association between folate concentrations and birth defects of other neural crest cell-derived organs remains unknown. We investigated the associations between birth defects and first-trimester serum folate concentrations in a birth-cohort study in Japan.

Methods: In total, 14,896 women who were prior to 13 weeks of gestation were enrolled from 2003 through 2012. Birth defect information was obtained from medical records and questionnaires. The association between folate levels in the first trimester and birth defects categorized as ICD-10 cord defects and neural crest cell-derived organ defects was examined. The crude and adjusted odds ratios (ORs) and 95% confidence intervals (CIs) per log-transformed folate concentration were calculated using logistic regression.

Results: Blood samples were obtained at a mean of 10.8 weeks of gestation. Median serum folate level was 16.5 (interquartile range, 13.4–21.5) nmol/L, and the deficiency level (less than 6.8 nmol/L) was 0.7%. There were 358 infants with birth defects. The adjusted odds ratio for any birth defect, ventricular septal defects, and cleft lip was 0.99 (95% CI, 0.74–1.32), 0.63 (95% CI, 0.30–1.33), and 4.10 (95% CI, 0.96–17.58), respectively. There were no significant associations between first-trimester maternal serum folate and the risk of birth defects.

Conclusions: We were unable to demonstrate a relationship between maternal serum folate in the first trimester and birth defects. Potential confounding factors may have influenced our results.

Background: Participation in leisure activities (LA) is essential for successful aging. Our aim was to investigate the cross-sectional association of types of LA with self-rated health (SRH) by gender and work status.

Methods: The target population was all residents aged ≥65 years in a municipality (n = 16,010, response rate of 62.5%). We analyzed 4,044 men and 4,617 women without disabilities. LA were categorized into 14 types. SRH was assessed through the SF-8. Excellent or very good SRH was defined as positive SRH. Covariates included age, marital status, education, subjective economic status, body mass index, chronic diseases, alcohol, smoking, walking time, depression and cognitive functioning. Multiple logistic regressions were used to calculate the odds ratio (OR) and 95% confidence interval (CI) for positive SRH, with non-participation as the reference.

Results: After adjustment for covariates and mutual adjustment for other LA, participation in the following types of LA was positively associated with positive SRH: regarding sports activities, working men (OR = 1.46, 95% CI = 1.07-2.00), non-working men (1.33, 1.04-1.69), and non-working women (1.74, 1.41-2.15); regarding cooking, non-working men (1.65, 1.18-2.33) and non-working women (1.28, 1.03-1.60); regarding musical activities, working men (1.44, 1.01-2.05) and non-working women (1.59, 1.29-1.95); and regarding technology usage, only working men (1.41, 1.01-1.96). In contrast, TV watching was negatively associated with positive SRH among non-working women (0.69, 0.56-0.85).

Conclusions: Our results suggest that encouraging older adults to participate in types of LA appropriate to their gender and work status might be a key to positive SRH.

Background: Japan became the first country where heat-not-burn tobacco products were sold. Therefore, there was no information for actual status of heat-not-burn tobacco products.

The objectives of the study profile are to inform that data can be freely available to external researchers, and to create collaborative research projects in the future.

Methods: The Japan “Society and New Tobacco” Internet Survey (JASTIS) is a longitudinal internet cohort study which investigates perception, attitude and use of heat-not-burn tobacco, electronic cigarettes (e-cigarettes) and conventional tobacco products in Japan. The survey also includes demographic, health-related and socioeconomic factors. Participants were randomly selected and invited from internet panellists. The baseline survey was closed when the target number of respondents who had answered the questionnaire was met.

Results: The study includes three cohorts (1-3) from the 2015 baseline survey and a cohort (4) from the 2017 baseline survey: cohort 1&4 were recruited based on sex and age: men and women aged 15-69 years (n=8240 for cohort 1 and n=5897 for cohort 4); cohort 2&3 were made by use status-based recruiting: e-cigarette and/or heat-not-burn tobacco ever users (n=2188; cohort 2) and combustible cigarette smokers without e-cigarette/heat-not-burn tobacco experience (n=724; cohort 3). The completion rates were 8.5 to 9.9%. All subjects were followed and assessed annually. Response rates for the follow-up survey were 65.5% in 2016, 55.3% in 2017 and 50.9% in 2018. Because Internet-based responders differ from the representative sample in Japan, we conducted the adjustment to account for “being an internet survey respondent” and reported about the products use in Japan. Recent study reported that prevalence of IQOS current-use among Japanese adults had rapidly increased to 3.6% in 2017.

Conclusion: The JASTIS study provides the first estimates for heat-not-burn tobacco use in the world and e-cigarette use in Japan. For information on collaboration, please contact the corresponding author.

Objective: Colorectal cancer (CRC) is the 4^th common site for cancer death in Republic of Korea. The aim of this study was to describe the trends of colorectal cancer mortality by regions.

Methods: CRC mortality trends in Republic of Korea by region were described using a Joinpoint regression model in both sexes. The annual percent changes (APC) were calculated for each segment. Visualization of the changes in mortality rate of colorectal cancer death rates by 16 geographic areas in both sexes between 2000-2004 and 2009-2013 were also conducted.

Results: CRC mortality rates of men showed decreasing trend after increase in Daegu, Gyeongsangnam-do and Chungcheongbuk-do between 2000 and 2013 based on the joinpoint model. While, Gwangju, Jeollabuk-do, Jeollanam-do, Gyeongsangbuk-do showed increase in CRC mortality during the same period. For women, CRC mortality of Seoul, Incheon, Daejeon and Gyeongsangnam-do started to decrease in 2005, 2003, 2007 and 2006 respectively. The mortality rate for CRC in the eastern regions, which had relatively low rates of CRC among men in 2000 to 2004, reached a level similar to that in the northwestern regions of 2009 to 2013, while the highest CRC mortality rates in women was observed in Chungcheongbuk-do.

Conclusions: Reduction in CRC mortality varied across 16 metropolitan cities and provinces in men, and the visualization pattern showed that the east side of South Korea had the least progress in mortality reduction.

Background: To examine the relationship of working history from early adulthood through old age with instrumental activities of daily living (IADL).

Methods: Analyzed participants were 5,857 community-dwelling older Japanese people aged ≥65 years. Using the Tokyo Metropolitan Institute of Gerontology Index of Competence, IADL decline was defined as individuals who had no IADL dependence at baseline but were deemed as dependent in IADL at follow-up. Work history was based on working status at baseline, total working years, and information concerning the longest held job, including occupation, employment pattern, and workplace size (number of employees). We conducted multiple logistic regression analyses and estimated the odds ratios (ORs) for IADL decline with 95% confidence intervals (CIs) by gender.

Results: At the 33-month follow-up, 428 men (16.6%) and 275 women (8.4%) developed IADL decline. After covariate adjustments, men with unstable employment reported significantly increased IADL decline (OR 1.52; 95% CI, 1.19–1.95) compared to men with stable employment, and men who worked in small workplaces with 1–49 employees had an increased risk for IADL decline (OR 1.53; 95% CI, 1.21–1.93) compared to men in large-sized workplaces with ≥50 employees. After mutual adjustment for all working history items, only the association between small workplaces and IADL decline remained significant in men (OR 1.37; 95% CI, 1.03–1.84). Among women, none of the working history items were associated with IADL decline.

Conclusion: Our results suggest that not only promoting older people’s workforce participation, but also providing workers employed at small workplaces with sufficient occupational health services, may be effective in helping men retain IADL in later life.

Background: Inherited factors and maternal behaviors are thought to play an important role in the etiology of several congenital malformations. Twin studies can offer additional evidence regarding the contribution of genetic and lifestyle factors to common birth anomalies, but few large-scale studies have been reported.

Methods: We included data from twins (20,803 pairs) from the population-based California Twin Program. We compared concordance in monozygotic (MZ) to dizygotic (DZ) twins for the following birth anomalies: clubfoot, oral cleft, spina bifida, muscular dystrophy, deafness, cerebral palsy, strabismus, and congenital heart defects. Each birth anomaly was also examined for the associations with birth characteristics (birthweight and birth order) and parental exposures (age, smoking, and parental education).

Results: The overall prevalence of any selected birth anomaly in California twins was 38 per 1,000 persons, with a slightly decreasing trend from 1957–1982. For pairwise concordance in 6,752 MZ and 7,326 like-sex DZ twin pairs, high MZ:DZ concordance ratios were observed for clubfoot (CR 5.91; P = 0.043) and strabismus (CR 2.52; P = 0.001). Among the total 20,803 pairs, parental smoking was significantly associated with risk of spina bifida (OR 3.48; 95% CI, 1.48–8.18) and strabismus (OR 1.61; 95% CI, 1.28–2.03). A significant quadratic trend of increasing risk for clubfoot, spina bifida, and strabismus was found when examining whether father smoked, mother smoked, or both parents smoked relative to non-smoking parents (P = 0.029, 0.026, and 0.0005, respectively).

Conclusions: Our results provide evidence for a multifactorial etiology underlying selected birth anomalies. Further research is needed to understand the biological mechanisms.

Background: Practical criteria for the use of serum pepsinogen (PG) values in diagnosing Helicobacter pylori infection have not yet been determined.

Methods: The results of gastric endoscopies, H. pylori infection tests, and PG values were retrospectively reviewed. Subjects were assigned to groups, including never-infected (with neither infection nor gastric mucosal atrophy), infected (with atrophy or findings indicating infection in endoscopy and positive infection tests except for antibody tests), and ex-infected (with gastric mucosal atrophy and negative infection tests, except for antibody tests). The optimal criteria with combined use of the PG II concentrations and the PG I/PG II ratio were investigated separately for PG measurements obtained with the chemiluminescent magnetic particle immunoassay (CLIA) and latex agglutination (LA) methods, such that the specificity was greater than 70% and the sensitivity was no less than 95% among the never-infected and infected subjects. Similar analyses were performed by combining the data from ex-infected and infected subjects.

Results: For the CLIA (LA) method, the optimal criterion among 349 (397) never-infected and 748 (863) infected subjects was a PG II value of at least 10 (12) ng/mL or a PG I/PG II ratio no more than 5.0 (4.0), which produced 96.3% (95.1%) sensitivity and 82.8% (72.8%) specificity. When 172 (236) ex-infected subjects were included, the optimal criterion was the same, and the sensitivity was 89.1% (86.9%).

Conclusions: The above criteria may be practical for clinical use, and PG tests using these criteria might prevent unnecessary endoscopic examinations for never-infected subjects.

Background: It is known that physical activity affects glucose metabolism. However, there have been no reports on the influence of physical activity earlier in life on subsequent glucose metabolism. Therefore, we analyzed the influence of physical activity in earlier decades of life on insulin resistance in middle aged and older residents in Japan.

Methods: The subjects were 6,883 residents of Okazaki City between the ages of 40 and 79 years who underwent physical examinations at the Okazaki City Medical Association Public Health Center from April 2007 through August 2011. They gave informed consent for participation in the study. Data on individual characteristics were collected via a questionnaire and from the health examination records. Fasting blood glucose and insulin levels were used to calculate the homeostatic model assessment of insulin resistance (HOMA-IR). HOMA-IR >1.6 was considered to indicate insulin resistance for the purpose of logistic regression models.

Results: The study sample included 3,683 men and 3,200 women for whom complete information was available. For those who exercised regularly throughout their teens to their 30s–40s, the odds ratio for having insulin resistance was 0.75 (95% confidence interval [CI], 0.58–0.96) for men and 0.76 (95% CI, 0.58–0.99) for women after adjusting for other variables, including age, body mass index, and present physical activity. A linear trend was also observed in both men and women.

Conclusions: Subjects who have exercised regularly in the early decades of life are less likely to have insulin resistance later in life.

Background: The association between daily walking and pneumonia mortality, stratified by the presence of disease conditions, such as myocardial infarction (MI) or stroke, was investigated.

Methods: The study participants were 22,280 Japanese individuals (9,067 men and 13,213 women) aged 65–79 years. Inverse propensity weighted competing risk model was used to calculate the hazard ratio (HR) and 95% confidence interval (CI) for pneumonia mortality.

Results: After a median of 11.9 years of follow-up, 1,203 participants died of pneumonia. Participants who did not have a history of MI or stroke and who walked for 1 hour/day or more were less likely to die from pneumonia (HR 0.90; 95% CI, 0.82–0.98) than those walked for 0.5 hours/day. A similar inverse association of pneumonia and walking (0.5 hours/day) was observed among participants with a history of MI (HR 0.66; 95% CI, 0.48–0.90). Among the participants with a history of stroke, those who walked for 0.6–0.9 hours/day were less likely to die because of pneumonia (HR 0.65; 95% CI, 0.43–0.98).

Conclusions: Regular walking for ≥1 hour/day may reduce the risk of pneumonia mortality in elderly individuals with or without cardiovascular disease history.

Background: The aims of the present report were to estimate the prevalence of congenital anomalies (CAs) among infants in Japan using data from the Japan Environment and Children’s Study (JECS) and to evaluate the validity of CA classification within JECS.

Methods: Data on CAs were collected at delivery and at age 1 month from the medical records of 101,825 infants at 15 regional centers. The analyses focused on 61 CAs, selected on the basis of reported associations with environmental exposure. Prevalence per 10,000 pregnancies (including miscarriages, stillbirths, and live births) was stratified according to four reporting patterns (at delivery, at age 1 month, at either, and at both). To evaluate the accuracy of observed CA prevalence, the medical records of 179 cases from a single JECS regional center underwent independent, retrospective re-evaluation.

Results: The prevalence of major CAs in four reporting patterns (at delivery, at age 1 month, at either, and at both) was 2.4, 2.6, 3.5, and 1.4 for myelomeningocele/spina bifida; 4.3, 4.2, 5.3, and 3.2 for cleft palate; 18.1, 17.4, 19.5, and 15.1 for cleft lip with or without cleft palate; 73.4, 100.3, 120.8, and 52.8 for congenital heart disease; and 10.5, 14.1, 15.0, and 9.6 for Down’s syndrome, respectively. In the subsample re-evaluation, CA diagnoses were confirmed for 92.7%, 93.3%, 90.5%, and 97.8% of cases in the four reporting patterns (at delivery, at age 1 month, at either, and at both), respectively.

Conclusions: The present report generated reliable data concerning the prevalence of major CAs in JECS.

Background: This study aimed to determine whether there are disparities in healthcare services utilization according to household income among people aged 75 years or older in Japan.

Methods: We used data on medical and long-term care (LTC) insurance claims and on LTC insurance premiums and needs levels for people aged 75 years or older in a suburban city. Data on people receiving public welfare were not available. Participants were categorized according to household income level using LTC insurance premiums data. The associations of low income with physician visit frequency, length of hospital stay (LOS), and medical and LTC expenditures were evaluated and adjusted for 5-year age groups and LTC needs level.

Results: The study analyzed 12,852 men and 18,020 women, among which 13.3% and 41.5%, respectively, were categorized as low income. Participants with low income for both genders were more likely to be functionally dependent. In the adjusted analyses, lower income was associated with fewer physician visits (incidence rate ratio [IRR] 0.90; 95% confidence interval [CI], 0.87–0.92 for men and IRR 0.97; 95% CI, 0.95–0.99 for women), longer LOS (IRR 1.98; 95% CI, 1.54–2.56 and IRR 1.42; 95% CI, 1.20–1.67, respectively), and higher total expenditures (exp(β) 1.09; 95% CI, 1.01–1.18 and exp(β) 1.09; 95% CI, 1.05–1.14, respectively).

Conclusions: This study suggests that older people with lower income had fewer consultations with physicians but an increased use of inpatient services. The income categorization used in this study may be an appropriate proxy of socioeconomic status.

Background: Understanding the area-specific resource use of inpatient psychiatric care is essential for the efficient use of the public assistance system. This study aimed to assess the geographical variation in psychiatric admissions and to identify the prefecture-level determinants of psychiatric admissions among recipients of public assistance in Japan.

Methods: We identified all recipients of public assistance who were hospitalized in a psychiatric ward in May 2014, 2015, or 2016 using the Fact-finding Survey on Medical Assistance. The age- and sex-standardized number of psychiatric admissions was calculated for each of the 47 prefectures, using direct and indirect standardization methods.

Results: A total of 46,559 psychiatric inpatients were identified in May 2016. The number of psychiatric admissions per 100,000 population was 36.6. We found a 7.1-fold difference between the prefectures with the highest (Nagasaki) and lowest (Nagano) numbers of admissions. The method of decomposing explained variance in the multiple regression model showed that the number of psychiatric beds per 100,000 population and the number of recipients of public assistance per 1,000 population were the most important determinants of the number of psychiatric admissions (R² = 28% and R² = 23%, respectively). The sensitivity analyses, using medical cost as the outcome and data from different survey years and subgroups, showed similar findings.

Conclusions: We identified a large geographical variation in the number and total medical cost of psychiatric admissions among recipients of public assistance. Our findings should encourage policy makers to assess the rationale for this variation and consider strategies for reducing it.

Background: Histological classification of lung cancer is essential for investigations of carcinogenesis and treatment selection. We examined the temporal changes of lung cancer histological subtypes.

Methods: Lung cancer cases diagnosed in the Life Span Study cohort between 1958 and 1999 were collected from tumor registries (TR), mainly consisting of population-based cancer registries. A total of 1,025 cases were histologically reviewed according to the World Health Organization 2004 Classification by a panel of pathologists (PP). Sensitivity and specificity of diagnoses in TR were calculated, assuming that the diagnosis by PP was the gold standard.

Results: Sensitivity and specificity were 0.91 and 0.92 for adenocarcinoma (AD), respectively, and 0.92 and 0.94, respectively, for squamous cell carcinoma (SQ). They were similar for AD and SQ throughout the observation period. For small cell carcinoma (SM), sensitivity was low until about 1980 (0.47 in 1958–1969, and 0.61 in 1970–1979) and then became higher thereafter (0.98 in 1980–1989, and 0.95 in 1990–1999), whereas specificity was high during the whole period (range 0.99 to 1.00). Among 45 cases that were not reported as SM in TR but diagnosed as SM by PP, 16 cases were recorded as undifferentiated carcinoma in TR.

Conclusion: Diagnosis of AD and SQ of lung cancer were generally consistent between TR records and PP review, but SMs tended to be coded as other histological types until the 1970s.

Background: A better understanding of resource use of new psychiatric admissions is important for healthcare providers and policymakers to improve psychiatric care. This study aims to describe the pattern of new psychiatric admissions and length of stay in Japan.

Methods: A retrospective cohort study was conducted using data from the National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB). All patients newly admitted to psychiatric wards from April 2014 through March 2016 were included and followed up until discharge to the community.

Results: Our sample included 605,982 admissions from 1,621 hospitals over 2 years. The average monthly number of admissions was 25,024 in fiscal year 2014 and 25,475 in fiscal year 2015. There was a seasonal trend in the number of admissions, with a peak in summer (in July). The discharge rates within 90 days and 360 days were 64.1% and 85.7%, respectively, and varied by type of hospital fee and by hospital. For example, the range of hospital-level discharge rate within 90 days in psychiatric emergency units was 46.0–75.3% in the 1st (lowest) quintile, while it was 83.6–96.0% in the 5th (highest) quintile. The prefecture-level indicators in the NDB and the 630 survey had correlations of >0.70.

Conclusions: Our study provides fundamental information on resource use of new psychiatric admissions in Japan. Although using the NDB has substantial benefits in monitoring resource use, the results should be interpreted with some caution owing to methodological issues inherent in the database.

Background: It is unclear whether either neighborhood collective efficacy or school collective efficacy is associated with adolescent alcohol use. This study aimed to examine the relative contributions of collective efficacy, both in school and in the neighborhood contexts, to alcohol use among Japanese adolescents.

Methods: A cross-sectional study was conducted in public high schools across Okinawa and Ibaraki Prefectures in Japan in 2016. The study participants consisted of 3,291 students in grades 10 through 12 cross-nested in 51 schools and 107 neighborhoods. Alcohol use was measured as current alcohol drinking, which was defined as self-reported drinking on at least 1 day in the past 30 days. Collective efficacy was measured using scales of social cohesion and informal social control in school and the neighborhood. Contextual-level collective efficacy was measured using aggregated school-level and neighborhood-level individual responses, respectively. We used non-hierarchical multilevel models to fit the cross-nested data.

Results: Significant variation in alcohol use was shown between schools but not between neighborhoods. After adjusting for covariates, school collective efficacy at individual- and contextual-levels was protectively associated with alcohol drinking (odds ratio [OR] for the increase of one standard deviation from the mean 0.72; 95% confidence interval [CI], 0.63–0.82 and OR 0.61; 95% CI, 0.49–0.75, respectively), whereas neighborhood collective efficacy at individual- and contextual-levels was not associated with alcohol consumption.

Conclusion: The school-level associations of collective efficacy with adolescent alcohol use may have the greater impact than the neighborhood-level associations. Adolescent drinking prevention efforts should include enhancing school collective efficacy.

Background: The different profiles of e-cigarette users in different age groups have seldom been investigated, particularly in populations facing a high prevalence of cigarette smoking. This study aims to examine the prevalence and correlates of e-cigarette use separately for adolescents and adults in nationally representative samples in Taiwan.

Methods: Among 17,837 participants in the 2014 National Survey of Substance Use in Taiwan, 4445 were aged 12 to 17 years and 13,392 were aged 18 to 64 years. Individuals’ lifetime tobacco use was divided into four groups: non-use, exclusive e-cigarette use, exclusive cigarette use, and dual use. Questions on sociodemographic features, use and problematic use of tobacco, alcohol, and other drugs, and psychosocial distress, among others, were administered using a computer-assisted self-interview on tablet computers.

Results: Among lifetime users of e-cigarette (2.2% for adults and 0.8% for adolescents), 4.5% for adults and 36.6% for adolescents were exclusive e-cigarette users. From use of exclusive e-cigarettes to use of exclusive cigarettes to dual use, those usage groups were related to an increasing trend of adjusted odds ratios for use of other psychoactive substances, particularly problematic use of alcohol or drugs, and with more depressive symptoms. Two correlates were specific to e-cigarette use: alcohol use had stronger relationships with e-cigarette use among adolescents, and younger adults (18–34) were more likely to try e-cigarettes compared to older adults.

Conclusions: These results provide essential information regarding e-cigarette use in the general population, and future prevention strategies should account for its specific correlates in young people.

Background: We aimed to report the prevalence and correlates of high-risk alcohol consumption and types of alcoholic beverages.

Methods: The baseline data of the Health Examinees-Gem (HEXA-G) study participants, including 43,927 men and 85,897 women enrolled from 2005 through 2013, were used for analysis. Joinpoint regression was performed to estimate trends in the age-standardized prevalence of alcohol consumption. Associations of demographic and behavioral factors, perceived health-related effects, social relationships, and the diagnostic history of diseases with alcohol consumption were assessed using multinomial logistic regression.

Results: The prevalence of alcohol consumption remained higher in men during the study period and increased in women. The amount of alcohol consumed has increased in women, especially that from beer and makgeolli, a traditional Korean fermented rice wine. Older participants were less likely to be high-risk drinkers (men and women who drink more than 40 or 20 g/day of alcohol, respectively) and drink Soju, a distilled liquor, and beer, and more likely to drink makgeolli. Educational level was negatively associated with high-risk drinking. However, it was positively associated with the consumption of strong spirits and wine. Smoking was associated with high-risk drinking and the consumption of soju and strong spirits. Engaging in regular exercise and having stress were associated with drinking all types of beverages except for soju.

Conclusions: Sex-specific trends in alcohol consumption were influenced by demographic, behavioral, and perceived health-related factors. The findings will help improve the understanding of alcohol-related problems and provide evidence for establishing country-specific policies and campaigns in Korea.

Background: Childhood constipation is prevalent and negatively affects quality of life. Although psychological stress and family environment have been identified as risk factors, few epidemiological studies have examined this issue. We aimed to clarify associations of psychological stress and family environment with childhood constipation in a large-scale epidemiological study.

Methods: In total, 7,998 children aged 9–10 years from the Toyama Birth Cohort Study completed questionnaires. Constipation was defined as bowel movements “less frequently than once every 2 days”. Children’s lifestyles, including food frequency, psychological stress, family environment, frequency of irritability, unwillingness to attend school, and frequency of interaction with their parents, were analyzed via multivariate logistic regression analysis. Parental employment status and presence at dinner were also examined.

Results: In total, 312 children (3.9%) experienced constipation. Girls were more likely to experience constipation than boys (5.1% vs 2.8%). In addition, constipation was significantly associated with girl (odds ratio [OR] 1.97; 95% confidence interval [CI], 1.55–2.51), physical inactivity (OR 1.41; 95% CI, 1.01–1.95), overweight (OR 0.58; 95% CI, 0.40–0.85), infrequent fruit (OR 1.94; 95% CI, 1.42–2.66) and vegetable (OR 1.46; 95% CI, 1.03–2.05) consumption, frequent irritability (OR 1.76; 95% CI, 1.24–2.50), unwillingness to attend school (OR 1.66; 95% CI, 1.13–2.43), and infrequent interaction with parents (OR 1.48; 95% CI, 1.06–2.07). Children whose parents were absent at dinner were more likely to experience constipation compared to those whose parents were present at dinner; however, this differences were not statistically significant.

Conclusion: Psychological stress and infrequent interaction with parents were as strongly associated with childhood constipation as conventional risk factors. Psychological stress and family environment should be more prioritized in caring childhood constipation.

Background: Previous studies have reported an additive effect of moderate-to-vigorous physical activity (MVPA) and sedentary time (ST) on depressive symptoms. However, no studies have been conducted in rural community settings. This cross-sectional study investigated whether the additive effect of MVPA and ST was associated with depressive symptoms in rural Japanese adults.

Methods: We identified 2,814 participants from health examinations conducted in Shimane, rural Japan, in 2012 and analyzed data from 1,958 participants. We assessed depressive symptoms using the Zung Self-Rating Depression Scale and measured the total time spent on MVPA and ST using a Japanese short version of the International Physical Activity Questionnaire. Poisson regression analysis examined the prevalence ratios (PR) of depressive symptoms in nine category combinations of MVPA level (no, insufficient, or sufficient MVPA) and ST level (high, moderate, or low ST).

Results: A total of 117 (6.0%) participants had depressive symptoms. Compared with the reference category (no MVPA/high ST), multivariate analysis showed that the likelihood of depressive symptoms was significantly lower in the sufficient MVPA/low ST category (PR 0.23; 95% confidence intervals [CI], 0.08–0.66), insufficient MVPA/low ST category (PR 0.37; 95% CI, 0.16–0.86), and insufficient MVPA/moderate ST category (PR 0.39; 95% CI, 0.17–0.90).

Conclusion: Analysis of the additive effect of MVPA and ST showed that the combinational category of sufficient MVPA and low ST had the lowest prevalence of depressive symptoms in rural Japanese adults. Moderate ST and low ST showed significantly lower likelihoods of depressive symptoms, regardless of insufficient MVPA.

Background: The effects, in terms of bias and precision, of omitting non-confounding predictive covariates from generalized linear models have been well studied, and it is known that such omission results in attenuation bias but increased precision with logistic regression. However, many epidemiologic risk analyses utilize alternative models that are not based on a linear predictor, and the effect of omitting non-confounding predictive covariates from such models has not been characterized.

Methods: We employed simulation to study the effects on risk estimation of omitting non-confounding predictive covariates from an excess relative risk (ERR) model and a general additive-multiplicative relative-risk mixture model for binary outcome data in a case-control setting. We also compared the results to the effects with ordinary logistic regression.

Results: For these commonly employed alternative relative-risk models, the bias was similar to that with logistic regression when the risk was small. More generally, the bias and standard error of the risk-parameter estimates demonstrated patterns that are similar to those with logistic regression, but with greater magnitude depending on the true value of the risk. The magnitude of bias and standard error had little relation to study size or underlying disease prevalence.

Conclusions: Prior conclusions regarding omitted covariates in logistic regression models can be qualitatively applied to the ERR and the general additive-multiplicative relative-risk mixture model without substantial change. Quantitatively, however, these alternative models may have slightly greater omitted-covariate bias, depending on the magnitude of the true risk being estimated.

Background: The association between induced abortion and birth control methods (including oral contraceptives and intrauterine devices) and breast cancer may vary among countries, due to the different usage and frequency of birth control methods and induced abortion among countries. A better understanding of this association may help in determining safer birth control methods for Chinese women.

Methods: A case-control study was conducted with a total of 794 cases and 805 controls. Standardized questionnaires were used to collect information on demographic characteristics, exposure to induced abortion, birth control methods, and other risk factors for breast cancer. Multivariate logistic regression was conducted to explore the association between birth control methods and breast cancer.

Results: Multivariate logistic regression analyses showed that having a history of medical abortions, ≥3 surgical abortions, or both medical and surgical abortions was associated with an increased risk of breast cancer in post-menopausal women (odds ratio [OR] 2.48; 95% confidence interval [CI], 1.14–5.40). Pre-menopausal women who had used intra-uterine devices (IUDs) for more than 20 years tended to have a lower breast cancer risk than other age-matched pre-menopausal women (OR 0.41; 95% CI, 0.25–0.68). Both pre-menopausal and post-menopausal women who had <20 years exposure to IUDs and those who had used two or more birth control methods (with the exception of women who used IUDs for more than 20 years) tended to have much higher breast cancer risk.

Conclusion: The relationship between induced abortion and birth control methods and breast cancer was complex, though being exposed to induced abortion and two or more birth control methods in one’s lifetime appeared to be risk factors for breast cancer in Chinese women.

Background: Limited evidence is available on the association of insulin-like growth factors (IGFs) and risk of heart failure in population-based samples. We investigated whether serum IGFs concentrations can predict mortality from heart failure.

Methods: We conducted a nested case-control study of 39,242 subjects aged 40–79 years who participated in the JACC study, a large Japanese prospective cohort study; participants provided serum samples and were followed up for 9 years. In heart failure cases and age-, sex-, community-, and year of blood withdrawal-matched controls, we measured serum concentrations of IGF-I, IGF-II, and IGF binding protein 3 (IGFBP3) and transforming growth factor (TGF-β1).

Results: During the follow-up, there were 88 heart failure deaths (44 men and 44 women). Each increment of 1 standard deviation [SD] of IGF-II (120.0 ng/mL in women and 143.7 ng/mL in men) was associated with a 47% reduced risk of mortality from heart failure; multivariable odds ratio was 0.53 (95% confidence interval [CI], 0.30–0.94, P-trend = 0.03). The multivariable odds ratio in the highest quartile of IGFBP3 serum concentrations (≥3.29 µg/mL in women and ≥3.31 µg/mL in men) compared with the lowest (<2.11 µg/mL in women and <2.56 µg/mL in men) was 0.24 (95% CI, 0.05–1.11; P-trend = 0.12). No association was found between serum concentrations of IGF-I or TGF-β1 and risk of heart failure.

Conclusions: Higher serum concentrations of IGF-II were associated with lower mortality from heart failure, which might suggest a possible role of IGF-II in the occurrence or prognosis of heart failure.

Background: In Japan, mean maternal age at first childbirth is increasing. The aim of this study was to investigate whether maternal age at the first childbirth is a risk factor for preterm birth (PTB), low birth weight (LBW), and small for gestational age (SGA).

Methods: We used the results of Japan Environment and Children’s Study (JECS) who gave birth in 2011–2014. Cases of primiparous singleton pregnancies where the subject was ≥20 years and delivered after 22 weeks were included. All subjects were categorized into five groups according to maternal age: 20–24, 25–29, 30–34, 35–39, and ≥40 years. Adjusted odds ratios (aORs) for PTB (before 37 and 34 weeks), LBW (<2,500 g and <1,500 g), and SGA were calculated using a logistic regression model, with the 20–24-year age group as reference.

Results: We analyzed 38,412 singleton primiparous pregnancies. The aORs of all outcomes increased in parallel with each maternal age group >30 years. The aORs of PTB before 37 and 34 weeks, LBW <2,500 g, LBW <1,500 g, and SGA in the 30–34-year age group were 1.39 (95% confidence interval [CI], 1.16–1.67), 2.23 (95% CI, 1.45–3.41), 1.34 (95% CI, 1.18–1.53), 2.30 (95% CI, 1.35–3.94), and 1.24 (95% CI, 1.05–1.46), respectively.

Conclusion: The present study showed that higher maternal age (>30 years) at the first childbirth was an independent risk factor for PTB, LBW, and SGA.

Background: Cholangiocarcinoma (CCA) is a common malignancy in northeastern Thailand. Over the last 4 decades, several policies have been implemented for its prevention, but there has been no update on the trends and relative survival (RS). Our aim was (a) to perform a statistical assessment of the incidence trends of CCA and project future trends, and (b) to estimate relative survival.

Methods: All cases of CCA diagnosed from 1989 through 2013 were abstracted from the Khon Kaen Cancer Registry (KKCR). A jointpoint regression model was used to estimate the annual percentage change (APC) and to project future trends. We also calculated RS.

Results: There were 11,711 cases of CCA. The incidence rate increased with an APC of 1.79% (95% confidence interval [CI], −0.2 to 3.8) from 1989 through 2002, and decreased with an APC of −6.09% (95% CI, −8.2 to −3.9) from 2002 through 2013. The projected incidence of CCA should stable over the next 10 years, albeit higher than the world rate. The respective 5-year RS for both sexes for age groups of 30–40, 41–45, 51–60, and 61–98 years was 22.3% (95% CI, 16.8–29.5), 14.3% (95% CI, 12.0–17.0), 8.6% (95% CI, 7.8–10.0), and 7.2% (95% CI, 6.4–8.0).

Conclusion: The incidence rate of CCA has decreased since 2002, representing a real decline in the risk of CCA. The incidence of CCA is projected to stabilize by 2025. The survival of patients with CCA remains poor.

Background: Simple physical fitness test can be a useful potential predictor of type 2 diabetes (T2DM). We examined the association between performances on simple physical fitness tests and the incidence of T2DM.

Methods: This longitudinal study was conducted in 21,802 nondiabetic Japanese (6,649 women) aged 20 to 92 years, who underwent all physical fitness tests at baseline (April 2001 to March 2002). From April 2001 to March 2008, physical fitness tests, including grip strength, vertical jump, single-leg balance with eyes closed, forward bending, whole-body reaction time, and supine legs-up, were performed every year. Participants had physical fitness tests at least two times during the period. T2DM was also annually determined based on fasting blood glucose, glycated hemoglobin, and self-reported diabetes during the period. Discrete-time logit models were used to examine the influence of the serial level of each physical fitness test on the incidence of T2DM.

Results: During the entire study period, 972 participants developed diabetes. Lower relative grip strength (grip strength/body weight) and single-leg balance performance were associated with a higher incidence of T2DM. For relative grip strength, as compared with the fourth quartile group, the odds ratios for other groups ranged from 1.16 to 1.56 (P for trend < 0.001). For single-leg balance, the odds ratios ranged from 1.03 to 1.49 (P for trend < 0.001).

Conclusion: The performance of a simple single-leg balance test as well as that of a grip strength test were negatively associated with the risk of T2DM among Japanese.