Journal of Epidemiology最新文献

Background: This study aimed to validate self-reported medical conditions in the Taiwan Biobank (TWBB), in which participants were inquired about 30 disease conditions, by comparing them with claims records from Taiwan's National Health Insurance (NHI) claims database.

Methods: We identified 30 clinical diagnoses using ICD-CM codes from ambulatory and hospital claims within the NHI claims database, matching diseases included in the TWBB. The concordance between self-reports and claims records was evaluated using tetrachoric correlation to assess the correlation between binary variables.

Results: A total of 131,834 participants aged 30-70 years with data from the TWBB and NHI records were included. Concordance analysis revealed tetrachoric correlations ranged from 0.420 (chronic obstructive pulmonary disease) to 0.970 (multiple sclerosis). However, several disorders exhibited lower tetrachoric correlations. The concordance was higher among those with higher education attainment, and lower among married individuals.

Conclusion: The concordance between self-reports in the TWBB and NHI claims records varied across clinical diagnoses, showing inconsistencies depending on participant characteristics. These findings underscore the need for further investigation, especially when these variables are crucial to research objectives. Integrating complementary databases such as clinical diagnoses, prescription records, and medical procedures can enhance accuracy through customized algorithms based on disease categories and participant characteristics and optimize sensitivity or positive predictive values to align with specific research objectives.

Background: A recent systematic review showed Japan's mortality from chronic obstructive pulmonary disease (COPD) is the lowest among 204 countries, despite notably higher smoking rates in men in Japan than in the US. This study aims to compare (1) trends in smoking rates, (2) trends in COPD mortality, and (3) the spirometry-based COPD prevalence in the general adult population between Japan and the US.

Methods: Age- and sex-specific smoking rates from the 1980s through 2010s and COPD mortality from 1999 through 2019 were obtained from national surveys and official statistics (International Classification of Diseases-10^th codes J40-44), respectively. A systematic review and meta-analysis was performed to estimate COPD prevalence in Japan, while the National Health and Nutrition Examination Survey 2007-2012 was used for the US. A fixed ratio of 0.7 of forced expiratory volume in the first second of forced vital capacity was used to define COPD.

Results: Over the past four decades, men in Japan consistently had 20-30% higher smoking rates than their US counterparts. From 1999-2019, age-adjusted COPD mortality in men in Japan was only a third of the US, whereas that in women was less than a tenth in 2019. Synthesizing data from 11 studies, involving 89,955 participants, Japan's COPD prevalence was more than 10% lower than in the US in almost all age groups for both sexes.

Conclusions: This study showed markedly lower rates of COPD in Japan than in the US. Investigating factors contributing to the paradoxical observations could lead to advancing COPD risk reduction strategies.

Introduction: This study aimed to determine the association between cumulative maternal physical activity level and their children's physical activity in early childhood. We also compared the influence of each maternal physical activity on children's physical activity in early childhood.

Methods: We analyzed the data from 1,067 Japanese mother-child pairs. Maternal physical activity was assessed using the International Physical Activity Questionnaire. Cumulative physical activity level in mothers was computed based on the categories (low, moderate, and high) of physical activity from 5 time points (pre-pregnancy, during pregnancy, 1.5, 3.5, and 5.5 years postpartum). Children's physical activity level was measured at age 5.5 years using the WHO Health Behaviour School-aged Children questionnaire and defined as engaging in physical activity for at least 60 minutes per day for more than 5 days. Logistic regression analysis was used to determine the association between maternal and children's physical activity levels.

Results: The results showed the positive association between cumulative maternal physical activity and children's physical activity level (P for trend < 0.001). Furthermore, maternal physical activity during pregnancy (P for trend = 0.031) and 5.5 years postpartum (P for trend < 0.001) was positively associated with children's physical activity.

Conclusion: A positive association was observed between the cumulative maternal physical activity level and the physical activity level of their children at 5.5 years of age. Furthermore, maternal physical activity during pregnancy and at 5.5 years postpartum were positively associated with the level of children's physical activity.

Background: The decline in measles vaccination coverage is a global concern. In Japan, coverage of the first-dose of measles vaccine, which had exceeded the target of 95.0% since fiscal year (FY) 2010, fell to 93.5% in FY 2021. Vaccination coverage increased to 95.4% in FY 2022 but varied by municipality. Few studies have focused on regional disparities in measles vaccination coverage. This study aimed to clarify the regional disparities in measles vaccination coverage by municipality in Japan and their associated factors.

Methods: In this ecological study, the measles vaccination coverage in FY 2022; population density; area deprivation index (ADI, an indicator of socioeconomic status); proportion of foreign nationals, single-father households, single-mother households, and mothers aged ≥30 years; and number of medical facilities, pediatricians, and non-pediatric medical doctors in 1,698 municipalities were extracted from Japanese government statistics. Negative binomial regression was performed with the number of children vaccinated against measles as the dependent variable, number of children eligible for measles vaccination as the offset term, and other factors as independent variables.

Results: Vaccination coverage was less than 95.0% in 54.3% of municipalities. Vaccination coverage was significantly positively associated with population density and negatively associated with the proportion of single-father households, mothers aged ≥30 years, and the ADI (incidence rate ratio [IRR]: 1.004, 0.976, 0.999, 0.970, respectively).

Conclusion: This study showed regional disparities in measles vaccination coverage in Japan. Single-father households, age of mothers, and socioeconomic status may be key factors when municipalities consider strategies to improve vaccination coverage.

Background: Currently, awareness about platelet count (PC) and its consequences for perinatal outcome have increased, but there is little reliable evidence on fecundability.

Methods: Based on the National Free Pre-conception Check-up Projects supported by the Chinese government, 5,524,886 couples met the inclusion criteria and were included in this cohort study. Cox regression models were adopted to estimate fecundability ratios (FRs) and their 95% confidence intervals (CIs) for pre-pregnancy PC quintiles. Restricted cubic splines were used to flexibly model and visualize the relationship of PC with FRs. Microsoft SQL server and R software were used for data management and analysis.

Results: The median of pre-pregnancy PC among women was 221.00 × 10⁹/L. The first (<177.00 × 10⁹/L) and second quintile (177.00-207.99 × 10⁹/L) of PC showed slightly increased fecundability (Q1: adjusted FR 1.05; 95% CI, 1.04-1.06; Q2: adjusted FR 1.04; 95% CI, 1.03-1.05), while higher quintals (Q4: 236.00-271.99 × 10⁹/L; Q5: ≥272.00 × 10⁹/L) were related to reduction of fecundability, when compared with the third quintile of PC (208.00-235.99 × 10⁹/L) (Q4: adjusted FR 0.96; 95% CI, 0.95-0.97; Q5: adjusted FR 0.88; 95% CI, 0.87-0.89). In the first quintiles (<177.00 × 10⁹/L), only 20.93% women had PC below 129.94 × 10⁹/L. An inverse-U-shaped association was consistently observed among women such that the lower PC within the normal range (<118.03 × 10⁹/L) and higher PC (>223.06 × 10⁹/L) were associated with the risk of reduced female fecundability (P for non-linearity < 0.01).

Conclusion: PC is associated with female fecundability. Further classification of PC levels may deepen our understanding of the early warnings and significance of female fecundability.

Background: The coronavirus disease 2019 (COVID-19) pandemic has affected cancer care. The aim of this study was to clarify the trend of colorectal cancer (CRC) stage distribution in Japan during the COVID-19 pandemic.

Methods: In this retrospective study, we used an inpatient medical claims database established at approximately 400 acute care hospitals. From the database, we searched patients who were identified as having the main disease (using International Classification of Diseases, 10^th revision codes [C18.0-C20]) between January 2018 and December 2020. A multivariate logistic regression analysis was used to determine the impact of the pandemic on CRC stage distribution each month, and the odds ratio (OR) for late-stage cancer was calculated.

Results: We analyzed 99,992 CRC patients. Logistic regression analysis, including the interaction term between increased late-stage CRC effect during the pandemic period and by each individual month, showed that the OR for late-stage CRC was highest in July during the pandemic, at 1.31 (95% confidence interval [CI], 1.13-1.52) and also significantly higher in September at 1.16 (95% CI, 1.00-1.35).

Conclusion: We investigated the trend of CRC stage distribution during the COVID-19 pandemic using a nationwide hospital-claims database in Japan and found that the proportion of early-stage cancers tended to decrease temporarily after the state of emergency declaration due to the COVID-19 pandemic, but the effect was only temporary.

Background: We prospectively examined the associations of total fat and fatty acid intake with type 2 diabetes (T2D) among Japanese adults.

Methods: This study was conducted using data from the Japan Collaborative Cohort Study for Evaluation of Cancer Risk (JACC). A validated food frequency questionnaire evaluated the intake of total fat and fatty acids. Diabetes was assessed using self-reported data. Multivariable logistic regression analysis was performed to calculate the odds ratios (ORs) and 95% confidence intervals (CIs) of incident T2D across quintiles of total fat and fatty acid intake after adjusting for potential confounders.

Results: A total of 19,088 non-diabetic participants (age range, 40-79 years) enrolled in the JACC between 1988 and 1990 were included in this study. During the 5-year study period, 494 the participants developed T2D. The OR of T2D for the highest versus lowest quintiles was 0.58 (95% CI, 0.37-0.90) for total fat, 0.78 (95% CI, 0.51-1.20) for saturated fatty acid (SFA), 0.55 (95% CI, 0.35-0.86) for monounsaturated fatty acids (MUFA), 0.61 (95% CI, 0.39-0.96) for polyunsaturated fatty acids (PUFA), 0.64 (95% CI, 0.42-0.99) for n-3 PUFA, and 0.70 (95% CI, 0.45-1.09) for n-6 PUFA. Total fat and fatty acid (except SFA and n-6 PUFA) intake were inversely associated with T2D in men. Total fat and fatty acid intake were not associated with T2D in women.

Conclusion: Higher intakes of total fats, MUFA, PUFA, and n-3 PUFA were inversely associated with T2D among Japanese men.

Background: In regions with a high prevalence of peanut allergy (PA), there is a consensus that the introduction of peanuts in early infancy is preventive against the development of PA. However, few studies have investigated whether the introduction of peanuts to infants is associated with PA in regions with a low prevalence of PA, including Japan.

Methods: We used data from 74,240 mother-child pairs who participated in the Japan Environment and Children's Study, a prospective birth cohort recruited between January 2011 and March 2014. A logistic regression model was used to analyze the association between infantile peanut introduction and PA at the age of 4 years with non-infantile peanut introduction as the reference group, adjusted for potential confounders.

Results: The percentage of infantile peanut introduction was 4.9% (n = 3,294), and 286 (0.4%) participants had allergic symptoms to peanuts at 4 years of age. Of all participants, 129 (0.2%) had PA at 4 years of age, which was defined as allergic symptoms and sensitization to peanuts. Those with infantile peanut introduction had a lower prevalence of PA than those without infantile peanut introduction, although this did not reach statistical significance (adjusted odds ratio 0.53; 95% confidence interval, 0.17-1.68). Sensitivity analysis using IgE-mediated symptoms caused by peanuts as the outcome showed a similar result in relation to infantile peanut introduction.

Conclusion: In countries with a low prevalence of PA, the effect of infantile peanut introduction on PA prevention was unclear.

Background: Studies on the association between preserved ratio impaired spirometry (PRISm) and dementia are limited. Indeed, PRISm has often been overlooked or ignored as an index of lung function impairment. Therefore, we investigated the association of PRISm with the risk for the development of dementia in an older Japanese population.

Methods: A total of 1,202 community-dwelling, older Japanese participants aged ≥65 years without dementia were followed up for a median of 5.0 years. Participants were categorized by spirometry as follows: normal spirometry (FEV₁/FVC ≥0.70 and FEV₁ ≥80% predicted), PRISm (≥0.70 and <80%), airflow limitation (AFL) Global Initiative for Chronic Obstructive Lung Disease (GOLD) 1 (<0.70 and ≥80%), and AFL GOLD 2 to 4 (<0.70 and <80%). Hazard ratios (HRs) and their 95% confidence intervals (CIs) were computed using a Cox proportional hazards model.

Results: During the follow-up period, 122 participants developed dementia. The age- and sex-adjusted incidences of dementia in the participants with normal spirometry, PRISm, AFL GOLD 1, and AFL GOLD 2 to 4 were 20.5, 37.0, 18.4, and 28.6 per 1,000 person-years, respectively. Participants with PRISm had a higher risk of dementia (HR 2.04; 95% CI, 1.19-3.49) than those with normal spirometry after adjusting for confounders. Moreover, both reduced FEV₁% predicted values and FVC% predicted values were associated with the risk of dementia.

Conclusion: PRISm was associated with an increased risk of dementia in a general older Japanese population.

Background: The novel coronavirus disease 2019 (COVID-19) pandemic has significantly impacted end-of-life decisions for cancer patients in Japan, with disparities existing between preferred and actual care settings. Our study investigates the potential shifts in cancer death locations during the pandemic and if there were excess cancer deaths.

Methods: Utilizing national mortality data from the Ministry of Health, Labour and Welfare from January 2012 to February 2023, we identified cancer deaths using International Classification of Disease, 10^th revision codes. We assessed death locations, including medical institutions, nursing facilities, and homes. The Farrington algorithm was employed to estimate expected death counts, and the differences between observed and expected counts were denoted as excess deaths.

Results: From January 2018 to February 2023, there was consistently increase in the weekly observed cancer deaths. The presence of a definitive excess during the pandemic period remains uncertain. The percentage of deaths in medical institutions declined from 83.3% to 70.1%, while home deaths increased from 12.1% to 22.9%. Between April 2020 and February 2023, deaths in medical institutions frequently fell below the 95% prediction lower limit. Home deaths consistently exceeded the 95% prediction upper limit, with significant excess deaths reported annually.

Conclusion: Our study found a shift in cancer death locations from medical institutions to homes in Japan during the COVID-19 pandemic. Our study did not confirm an overall increase in cancer deaths during this period. As with global trends, the profound shift from hospitals to homes in Japan calls for a comprehensive exploration to grasp the pandemic's multifaceted impact on end-of-life cancer care decisions.