Background: Preventable behavioral risk factors account for approximately one third of mortality, morbidity, and disability worldwide. This study aims to quantify the interest in behavioral risk factors within major medical journals in 2022 and to derive trends over the past 30 years in the entire medical literature.

Methods: We analyzed the proportion of publications dealing with tobacco smoking, alcohol drinking, use of illicit drugs, excess body weight and physical activity among all the 1,128 articles published in the Journal of the American Medical Association, the British Medical Journal, the Lancet, and New England Journal of Medicine in 2022. A joinpoint analysis was conducted running in PubMed/MEDLINE specific search strings to evaluate trends over the last 30 years in the four journals and in the whole medical literature.

Results: In 2022, of all publications from the four considered medical journals, 2.8% dealt with tobacco smoking, 1.6% alcohol drinking, 1.1% use of illicit drugs, 3.8% excess body weight, 2.7% physical activity and 8.0% dealt with any behaviors. The joinpoint analysis on the whole medical literature showed that papers on modifiable risk factors significantly increased from 3.9% in 1993 to 6.2% in 2014 (annual percent change [APC]: between +1.83% and +4.09%), and subsequently decreased between 2014 and 2019 (APC −0.31%), with an acceleration thereafter (APC −2.41% in 2019–2022).

Conclusion: For the first time we quantified the volume of medical research focused on preventable behavioral risk factors. This appears to be limited and declining over the last decade. Research on primary prevention should be a priority to face the emergence of associated non-communicable diseases globally.

Background: Despite Japan’s universal health insurance system, health disparities have increased since the 1990s. However, the impact of area deprivation on various aspects of child health remains understudied.

Methods: This population-based cohort study followed 38,554 children born in Japan (May 10–24, 2010) from birth to age 5.5 years. Using an outcome-wide approach, Bayesian three-level logistic regression models (individuals in municipalities within eight major regions) assessed associations between municipality-level Area Deprivation Index (ADI) at birth and multiple preschool health outcomes (hospitalizations for all causes; respiratory infections; gastrointestinal diseases; Kawasaki disease; medical visits for asthma, allergic rhinitis, atopic dermatitis, food allergy, injury, intussusception; prevalence of overweight/obesity), adjusting for individual-level factors.

Results: Higher ADI was associated with increased risk of all-cause hospitalization (adjusted odds ratio [aOR] per 1-standard-deviation increase in ADI, 1.04; 95% credible interval [CrI], 1.01–1.07), respiratory infections (aOR, 1.08; 95% CrI, 1.04–1.13), gastrointestinal diseases (aOR, 1.11; 95% CrI, 1.03–1.20), asthma (aOR, 1.10; 95% CrI, 1.01–1.19). Overweight/obesity at age 5.5 years also increased with higher ADI (aOR, 1.11; 95% CrI, 1.06–1.16). Higher ADI was inversely associated with Kawasaki disease (aOR, 0.86; 95% CrI, 0.77–0.96), though not robust in sensitivity analysis. Geographic clustering was observed for all outcomes, particularly at municipality level.

Conclusion: We found persistent municipal-level health inequalities across various childhood health outcomes in Japan, despite its universal health insurance system. These findings suggest that policymakers should address health inequalities through comprehensive strategies targeting broader social determinants beyond health care access.

Background: Older Japanese adults have the highest drowning mortality rates globally, likely due to in-home bathing customs. However, epidemiological evidence of preventive strategies based on national data is lacking. We aimed to describe the trends in bathtub drowning deaths (International Classification of Diseases, Tenth Revision code: W65) across Japan and explore factors that may reduce W65-coded deaths.

Methods: We collected the data of all W65-coded deaths that occurred at home from 1995 to 2020 using death certificates from the Ministry of Health, Labour and Welfare. The national age-adjusted mortality rates (AMRs) and prefecture-specific age-standardized mortality ratios (SMRs) were calculated. Data on demographic, socioeconomic, environmental factors, and nursing care services were obtained from the Japan Portal Site of Official Statistics. Mixed-effects analysis was used to examine the association between SMR and potential contributing factors at the prefecture level.

Results: We identified 99,930 W65-coded deaths at home, with the highest incidence among individuals aged 80–84 years, peaking in January. Since 2010, AMRs have consistently exceeded 3.0 per 100,000. An inverse association was found between SMR and the number of geriatric health service facilities and senior welfare centers per capita (coefficients per 1 standard deviation increase, −0.09; 95% confidence interval (CI), −0.13 to −0.05, P < 0.001 and −0.07; 95% CI, −0.11 to −0.02, P = 0.004, respectively), after adjusting for demographic, socioeconomic, and environmental factors.

Conclusion: Sustained high AMRs suggest that the rising death toll was not solely due to aging. Increased access to nursing care facilities may help prevent W65-coded deaths.

Background: Menarche timing may affect female health. While previous studies evaluated self-reported age at menarche reproducibility, they did not assess types of respondents. This study compared the reproducibility of age at menarche among self-responders and proxy respondents and assessed proxy-respondent reproducibility by relationship and survey age.

Methods: Data on age at menarche reported in both the 1969 and 1978 mail questionnaires among 9,043 females from the Life Span Study cohort of atomic bomb survivors were analyzed. The reproducibility of menarcheal age was assessed by the type of respondents, by proxy’s relationship to participant, and by age at the 1969 survey using Bland-Altman’s method and the intraclass correlation coefficient (ICC).

Results: Reproducibility was moderate (95% limits of agreement, −2.3 to 2.4 years; ICC 0.72; 95% confidence interval, 0.71–0.73). Both self-respondents (N = 6,664) and the total study population (N = 9,043) maintained moderate reproducibility even at older ages. Groups with proxy reports showed lower reproducibility than self-respondents, with spouse proxy reports showing highest reproducibility and parent proxy reports showing lowest reproducibility among proxy reports, although the comparisons are based on different survey ages in 1969.

Conclusion: This is the first study to evaluate menarcheal-age reproducibility between self- and proxy-reports using appropriate measures. Mail questionnaires at 9-year interval showed moderate reproducibility across all ages, including elderly self-respondents. Reproducibility varied by the respondent–target relationship, with spouse proxies showing highest and parent proxies showing lowest reproducibility among proxy reports. Additional data are required to establish appropriate methods for handling specific proxy responses.