Journal of Epidemiology最新文献

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.

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.

Background: 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.

Methods: Under the Japanese Next-Generation Healthcare Infrastructure Act, we obtained DPC data linked with the laboratory data of adult surgical patients with baseline and follow-up serum creatinine measurements from three hospitals (2021- 2024). Recorded diagnoses of AKI were identified using the International Classification of Diseases-10^th Revision codes (N17.x). The reference standard was the diagnosis of AKI per the creatinine-based Kidney Disease: Improving Global Outcomes (KDIGO) criteria. The sensitivity, specificity, likelihood ratios, and predictive values were calculated. We evaluated the coding validity for identifying AKI stages 2 and 3. Subgroup analyses were conducted according to baseline estimated glomerular filtration rates (eGFR) (≥60.0, 30.0-59.9, 15.0-29.9 mL/min/1.73 m²), type of admission (planned/emergent), and surgery type (cardiovascular/non-cardiovascular).

Results: Among 7,374 eligible patients, 663 (9.0%) met the KDIGO-defined AKI criteria, while 35 (0.5%) patients had the AKI codes. The sensitivity was 4.1% (95% CI, 2.7-5.9%), and specificity was 99.9% (95% CI, 99.8-99.9%). The sensitivity increased for patients with stages 2 and 3 AKI, lower eGFR, emergent admission, or cardiovascular surgery.

Conclusions: Among surgical patients, AKI coding in the DPC exhibited high specificity and positive predictive value, albeit low sensitivity. Incorporating laboratory data is important for more accurate identification of patients with AKI for use in clinical studies.

Background: 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.

Methods: We conducted a retrospective cohort study using the Japanese Diagnosis Procedure Combination (DPC) inpatient database from July 2010 to March 2023. Patients with a main diagnosis of meningococcal infection (ICD-10 code A39) were included. The primary outcome was in-hospital mortality. Secondary outcomes included impaired consciousness at discharge and functional status, assessed by the Barthel Index. Multivariable logistic regression was performed to identify prognostic factors.

Results: A total of 465 patients were analyzed. The median age was 55 years, and 57.0% were male. The in-hospital mortality rate was 8.2%, and 40.2% of survivors had a Barthel Index ≤90 at discharge. Early antibiotic administration did not significantly reduce mortality but was associated with improved neurological outcomes. Baseline impaired consciousness was the strongest predictor of mortality and poor functional status, while chronic comorbidities also contributed to worse outcomes. Notably, older age itself was not independently associated with mortality after adjustment for severity and comorbidities.

Conclusion: Meningococcal infection outcomes in Japan are predominantly determined by the severity of illness at presentation and comorbid health conditions rather than age alone. Early antibiotic therapy improves neurological recovery but may not prevent death once critical illness is established. These findings underscore the importance of prevention through vaccination and early recognition strategies to reduce the burden of this devastating infection.

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.