Meningococcal infection remains a life-threatening disease despite advances in early recognition and therapy. While the incidence of meningococcal infection is extremely low in Japan, nationwide data on its clinical outcomes have been lacking.

BackgroundMedical corporations (Iryohoujin) are central to Japan's healthcare delivery, yet their financial conditions have not been comprehensively assessed nationwide. This study aimed to describe financial trends and structural characteristics of hospital-operating corporations from fiscal year (FY) 2016 to FY2022 and examine fluctuations, including during the FY2020-FY2021 COVID-19 pandemic.MethodsA longitudinal analysis was conducted using financial data covering 95% of all hospital-operating medical corporations. Financial indicators, including total assets, medical revenue, and profit margin, were tracked from FY2016 to FY2022. Subgroup analyses were based on organizational size and integration. A linear mixed-effects model examined factors associated with profitability.ResultsThe number of hospital-operating medical corporations declined from 4,631 in FY2016 to 4,469 in FY2022. By FY2022, total assets and medical revenue reached 15.9 trillion JPY and 12.5 trillion JPY. Median medical profit margin declined from 1.8% (interquartile range [IQR], -1.2% to 5.3%) in FY2016 to 0.6% (IQR, -3.4% to 4.3%) in FY2021, then recovered to 1.6% (IQR, -2.5% to 5.5%) in FY2022. Smaller corporations, with fewer hospitals and beds, were more financially unstable, especially during the COVID-19 pandemic. A linear mixed-effects model showed that medical profit margin was negatively associated with hospital number and positively associated with long-term care and psychiatric beds.ConclusionsThis study highlights the structural scale and financial dynamics of Japanese medical corporations, revealing a large but unevenly resilient sector in which not only hospital size but also bed composition significantly influences profitability. These findings may inform policy discussions on healthcare system sustainability and financial support.

BackgroundThe Shanghai University of Sport (SUS) Longitudinal Cohort Study (SUS Cohort) was established to investigate the influence of lifestyle and modifiable behavioural factors in early adulthood on the development of non-communicable diseases (NCDs) later in life. The cohort aims to identify novel biomarkers and explore mechanisms underlying chronic diseases using a multi-omics approach.MethodsThe SUS Cohort study is a prospective cohort study of undergraduate students between 2018 and 2019, with follow-ups conducted every two years during early adulthood and every ten years thereafter. Comprehensive data collection includes body composition measurements, lifestyle surveys, physical fitness tests, and clinical laboratory tests. Multi-omics analysis, including genome-wide genotyping, gut microbiome and serum metabolome, is integrated to provide insights into disease pathophysiology.ResultsA total of 1,758 participants aged 18 to 22(mean age: 18.64 ± 3.15) were conducted from baseline surveys, with a follow-up period between September 2021 and September 2022. The median age at baseline was 18 years, and the proportion of female participants was about 871(49.5%). Of the initial participants, 1,055 individuals (60%) completed the follow-up.ConclusionThe SUS Cohort provides multidimensional data to study how early-life factors influence long-term health outcomes.

Researchers widely use the Diagnosis Procedure Combination (DPC) database for studies on acute-care hospitalization in Japan. However, the validity of acute kidney injury (AKI) diagnostic codes among patients who underwent surgery under general anesthesia is unclear.

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.

Evidence is scarce on cumulative SARS-CoV-2 infections among healthcare workers during the pandemic. This study aimed to describe cumulative infections, including undiagnosed cases, and identify factors associated with infection in healthcare workers in Japan.

In observational studies estimating the association between treatment and time-to-event outcomes, time-related biases can substantially impact results. Immortal time bias is one of such biases, and two types are known: misclassified immortal time bias and excluded immortal time bias. These biases often arise from incorrect time-zero definition, especially with non-user controls. This study aims to illustrate immortal time bias in non-user controls using formulas, simulations, and real-world data.

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.

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.

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.

BackgroundIn 2023, a collaborative UNICEF-WHO group introduced the concept of small vulnerable newborns (SVNs) to improve the identification of newborns at increased risk of adverse outcomes and to guide more effective preventive strategies. However, global data on the prevalence of SVNs remains scarce. This study aimed to examine secular trends in the prevalence of SVNs and their three subgroups, namely term small for gestational age (SGA), preterm SGA, and preterm non-SGA, in the Japanese population.MethodsWe analyzed data from vital statistics including livebirths and stillbirths between 1997 and 2021. Secular trends in the prevalence of SVNs and their subgroups were assessed. In addition, we conducted regional analyses to explore associations with the distribution of medical resources.ResultsA total of 26,172,760 newborns were included. The overall prevalence of SVNs was 7.8% in 1997, peaked at 8.7% in 2005, and declined to 7.7% by 2021. This decline was primarily attributed to a reduction in term SGA births. In contrast, the prevalence of preterm SGA and preterm non-SGA remained largely unchanged. In 2021, the prevalence of term SGA, preterm SGA, and preterm non-SGA was 2.0%, 0.44%, and 5.3%, respectively. No significant association was found between the regional variation in the prevalence of SVNs and the distribution of medical resources.ConclusionThe prevalence of SVNs in Japan has declined since 2005, mainly due to reduced term SGA births. Persistent rates of preterm subgroups highlight the ongoing burden of prematurity, underscoring the need for targeted strategies to improve neonatal outcomes.

Brief measures of 24-hour movement behaviors are needed to easily evaluate their durations. The present study investigated the criterion validity and test-retest reliability of a brief self-report instrument to assess 24-hour movement behaviors.

The potential impacts of polygenic scores (PGS) on health-behavior changes are not fully understood. The Iwate PGS Assessment and Risk Communication Study aims to investigate the effects of reporting PGS-based risk for ischemic stroke on health behaviors.

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.

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.

We aimed to investigate the association between women's birth weight and their reproductive characteristics.