Journal of Epidemiology最新文献

Background: This study aimed to assess the clinical relevance of three-dimensional occupational stress (job stressor score [A score], psychological and physical stress response score [B score], and social support for workers score [C score]) of the Brief Job Stress Questionnaire (BJSQ) in the national stress check program in Japan to irregular menstruation.

Methods: The present retrospective cohort study included 2,078 female employees aged 19-45 years who had both annual health checkups and the BJSQ between April 2019 and March 2022 in a national university in Japan. The outcome was self-reported irregular menstruation measured at annual health checkups until March 2023. A dose-dependent association between BJSQ scores and incidence of irregular menstruation was examined using Cox proportional hazards models to calculate multivariable-adjusted hazard ratios (HRs) of four quantile (0-49% [Q_0-49], 50-74% [Q_50-74], 75-89% [Q_75-89], and 90-100% [Q_90-100]) of the BJSQ scores.

Results: During 2.0 years of the median observational period, 257 (12.4%) women reported irregular menstruation. B score, not A or C scores, was identified as a significant predictor of irregular menstruation (adjusted HR of A, B, and C scores per 1 standard deviation: 1.06 [95% confidence interval {CI}, 0.89-1.27], 1.35 [95% CI, 1.15-1.57], and 0.93 [95% CI, 0.80-1.08], respectively). Women with higher B score had a significantly higher risk of irregular menstruation in a dose-dependent manner (adjusted HR of Q_0-49, Q_50-74, Q_75-89, and Q_90-100: 1.00 [reference], 1.38 [95% CI, 1.00-1.90], 1.48 [95% CI, 1.00-2.18], and 2.18 [95% CI, 1.38-3.43], respectively).

Conclusion: Psychological and physical stress response predicted irregular menstruation.

Background: Long-term sickness absence (LTSA) is an important public health challenge, yet limited data exist on its incidence in Japan. We aimed to describe the incidence of all-cause and cause-specific LTSA by sex and age using 10-year data from a large Japanese working population, with a focus on sex differences.

Methods: The study participants were employees from 16 worksites in the Japan Epidemiology Collaboration on Occupational Health Study between April 2012 and March 2022. LTSA, defined as sickness absence from work lasting 30 days or more, was recorded at each worksite. The causes of LTSA were classified using the International Classification of Diseases, 10th Revision. Incidence rates for all-cause and cause-specific LTSA were calculated based on sex and age.

Results: During 730,391 and 161,513 person-years of follow-up, 6,518 and 1,866 spells of LTSA were recorded in males and females, respectively. Females had higher incidence rates of all-cause LTSA than males (115.5 vs 89.2 per 10,000 person-years), especially among females in their 20s and 30s. This was partly attributed to younger females experiencing higher LTSA incidence rates due to mental disorders, neoplasms, and pregnancy-related illnesses. In older age, females had higher LTSA incidence rates than males for musculoskeletal diseases and injuries/external causes, whereas LTSA incidence rates due to circulatory diseases were lower than those in males.

Conclusion: The incidence of total and cause-specific LTSA varied greatly by sex and age, highlighting the need to consider employees' characteristics in the prevention and management of LTSA.

Background: Socioeconomic inequalities in cancer screening participation remain a public health issue worldwide. We assessed trends in cancer screening participation according to socioeconomic status in Japan between 2013 and 2022, considering the potential impact of the coronavirus disease 2019 (COVID-19) pandemic.

Methods: Data from the nationally representative Comprehensive Survey of Living Conditions (2013-2022: approximately 500,000 persons per survey) were analyzed for age-standardized self-reported cancer screening rates for stomach, lung, colon, breast (aged 40-69 years), and cervical (aged 20-69 years) cancers, stratified by education levels. An age-adjusted Poisson model was used to assess the statistical significance of changes between the survey years.

Results: A clear socioeconomic gradient was observed, particularly in stomach cancer screening, where the 2022 rates ranged from 28.3% (low education) to 58.2% (high education) for men and 20.2% to 43.2% for women, depending on education level. Between 2019 and 2022, screening rates for stomach, lung, and colorectal cancers changed by -1.2%, -0.9%, and +0.6% for men and -1.0%, +0.1%, and +1.4% for women, respectively. Breast and cervical cancer screening rates declined by 0.5% and 0.4%, respectively. The COVID-19 pandemic worsened inequalities, with a 3.1% decline in breast cancer screening among individuals with low education level, compared to a 1.0% decline among those with higher education level.

Conclusion: The COVID-19 pandemic had a minor impact on screening rates (counteracting increasing trends of screening rates), except for colorectal cancer screening rates; however, the impact was relatively severe for individuals with lower socioeconomic status, especially for women.

Background: Policy decisions should be guided by measures that capture the impact of exposures on outcomes and that explicitly account for present-day exposure distribution. Both the preventable and attributable fractions have been used for this purpose; however, exposure effects can vary across subpopulations, and when this occurs, appropriate interpretation of these measures should be facilitated by a discussion of the contributions of different subpopulations.

Methods: We analyze preventable and attributable fractions in the presence of effect modification. In particular, we use potential outcomes to formally define these quantities and to clarify the weighting of different strata in the total population measures.

Results: Our derivations show that stratum-specific preventable and attributable fractions are weighted in proportion to the relative frequencies of effect modifiers among individuals with the outcome of interest. We also demonstrate that these weights are valid for the related quantities, preventable and attributable proportions. Finally, we present an example that illustrates how effect modification affects interpretation of these measures.

Conclusions: In sum, when effect modification is present, investigators should consider reporting these measures by the relevant population strata, and information that would allow quantification of their implicit weights in the total population estimate. Our study provides a formal justification for this approach.

BackgroundA World Health Organization guideline recommends that adults engage in moderate-to-vigorous physical activity (MVPA). We aimed to clarify associations of total MVPA in any domain with overall and site-specific cancer incidence using Japanese population-based cohort data.MethodThis study evaluated 84,054 participants (39,053 males and 45,001 females aged 50-79 years) of the 10-year survey of the Japan Public Health Center-based Prospective Study over a median follow-up of 13.0 years. Total MVPA was calculated based on a self-reported physical questionnaire, and 7.5 metabolic equivalent-hours/week (MET-h/wk) was defined as the minimum amount recommended by the guideline. Associations of categorized total MVPA with overall and site-specific cancer incidences were examined using multivariable-adjusted Cox proportional hazard models by sex.ResultsAmong males, the risk reduction was non-significant even in the highest MVPA category compared with no total MVPA. Among females, in contrast, risk of total cancer was reduced even when they engaged in lower total MVPA than the recommended amount (0.1-7.4 MET-h/wk) compared with no total MVPA (hazard ratio 0.79 [95% confidence interval: 0.65-0.97]), and no further risk reduction was observed with increasing MVPA. Regarding site-specific cancers, engaging in higher total MVPA was inversely associated with risks of colon cancer (males) and bladder and endometrial cancers (females).ConclusionTotal MVPA was associated with reduced risk of overall cancer incidence in females, but not in males.

Background: Cardiovascular disease (CVD) remains a leading cause of death in Japan. Although several CVD risk scores tailored for Japanese individuals have been developed, no tools are available to estimate these scores at the population level. We developed the "Jcvrisk" R package, which integrates four major Japanese CVD risk models recommended by the clinical guideline. As a showcase, we applied the Jcvrisk package to longitudinal population-based study to evaluate trends in estimated different risk scores.

Methods: We used longitudinal data from the Yakumo Study, an annual health checkup for residents in Yakumo, Hokkaido. This package includes four risk models with 14 risk scores from representative cardiovascular cohort studies, including three EPOCH scores, one Hisayama score, two Suita scores, and eight JALS scores. For temporal comparisons of CVD risk scores, we summarized scores from 2000 to 2020 every five years.

Results: The mean age of participants throughout all study years was around 60 years old. Most risk factors did not change remarkably over the 20 years, with only a decrease in smoking prevalence and an increase in high density lipoprotein cholesterol (HDL-C). However, all CVD risk scores consistently indicated an upward trend in 10-year CVD risk.

Conclusions: Jcvrisk package includes functions to calculate CVD risk scores for Japanese adults. The package serves as a valuable tool for researchers and policymakers aiming to assess and monitor cardiovascular risk at both individual and population levels in Japan.

Background: Encouraging older drivers to display the older drivers' sign is one of the unique traffic safety policies for older drivers in Japan. The sign was discussed in light of ageism, but the potential merit of displaying it has not been investigated.

Methods: Using nationwide police-reported traffic crash data, we conducted a case-control study to examine whether displaying the sign is associated with reduced rear-end collision risk among drivers aged 70 years or older who were involved in car-to-car collisions from 2014 to 2023. The cases were those involved in rear-end collisions, the controls were those involved in angle collisions, and the exposure of interest was the sign display, which should be less often observed in the cases if the sign display is effective. The association was assessed with odds ratios adjusted for the time of crash and drivers' sex and age group.

Results: Among 74,433 cases and 13,885 controls, the proportion of those displaying older drivers' signs was 38% and 39%, respectively. By the time of crash and drivers' sex and age group, the proportion tended to be slightly higher in the cases than in the controls. In both cases and controls, the proportion was higher among women, in older age groups, and during daytime. The crude and adjusted odds ratios were 0.99 (95% confidence interval [CI]: 0.95-1.02) and 1.08 (95% CI: 1.04-1.12).

Conclusion: Displaying the older drivers' sign was not associated with reduced rear-end collision risk. Alternative interventions are needed to ensure their traffic safety.

Background: Health status in old age can be influenced by financial disadvantages both at present and in earlier life stages; however, few studies have focused on the long-term individual patterns of financial disadvantage over the life course. This study examined the relationship between trajectories of financial disadvantage over the life course and depressive mood among community-dwelling older Japanese adults.

Methods: Data were obtained from the 2012 National Survey of the Japanese Elderly using a two-stage stratified random sampling method. The sample consisted of 1,324 adults aged ≥60 years. We retrospectively assessed financial disadvantage at four life-course benchmark periods: ≤18 years old, 25-35 years old, 35-50 years old, and current age. Depressive mood was measured using the 8-item Center for Epidemiologic Studies Depression Scale.

Results: We identified five distinct life-course financial disadvantage trajectories using group-based mixture modeling: "persistently affluent" (22.1%), "increasing affluence" (21.7%), "consistently modest" (28.0%), "decreasing affluence" (11.3%), and "persistently poor" (17.0%). A logistic regression analysis showed that people in the "increasing affluence" subgroup were less likely to have a depressive mood than those in the "persistently poor" subgroup, after adjusting for potential covariates, including current income and parental educational attainment. This association was more prominent in women than in men.

Conclusion: The experience of escaping from financial disadvantages may bolster the mental health of older adults, regardless of sociodemographic characteristics, health behaviors, and health conditions. The mental health benefits of increasing affluence throughout the life course may be even stronger than the benefits of experiencing persistent affluence.

Background: More research is needed to clarify the health effects of dietary carotenoid intakes, and this requires the use of high-quality assessments of habitual dietary intake. Cohort studies from the Tohoku Medical Megabank Organization included a self-administered food frequency questionnaire (TMM-FFQ) for community-dwelling adults. This study evaluated the validity of carotenoid intakes derived from the TMM-FFQ using serum carotenoid concentrations as the gold standard.

Methods: In Miyagi Prefecture, 88 men and 124 women aged ≥20 years voluntarily agreed to participate in the study and provided completed TMM-FFQs and blood samples in 2019 and 2021. Carotenoids examined included α-carotene, β-carotene, β-cryptoxanthin, and lycopene. Intraclass correlation coefficients (ICCs) were calculated to assess correlations between serum concentrations in 2019 and 2021. Spearman's rank correlation coefficients were calculated to evaluate the correlations between energy-adjusted dietary carotenoid intakes from the TMM-FFQ in 2021 and the average serum carotenoid concentrations in 2019 and 2021, with correction for the attenuating effect of random within-individual variation.

Results: The ICCs between serum concentrations over the 2 years were >0.50 for all carotenoids. Among men, correlation coefficients were 0.33 for α-carotene, 0.42 for β-carotene, 0.50 for β-cryptoxanthin, and -0.09 for lycopene. Among women, the coefficients were lower than those for men, except for lycopene: 0.11 for α-carotene, 0.23 for β-carotene, 0.21 for β-cryptoxanthin, and 0.28 for lycopene.

Conclusions: The TMM-FFQ demonstrated reasonable validity for assessing intakes of α-carotene, β-carotene, and β-cryptoxanthin among men, but not among women, in the TMM cohort studies when using serum concentrations as the gold standard.