International journal of epidemiology最新文献

Background: Observational studies have reported lower ovarian cancer risk among individuals taking aspirin frequently (i.e. daily/near daily). However, most studies relied on a single assessment of aspirin use, which may have led to misclassification and precluded the examination of patterns of use over time. We examined the association between aspirin use, assessed at multiple time points, and ovarian cancer risk.

Methods: Data were pooled from 10 prospective cohort studies from the Ovarian Cancer Cohort Consortium (n = 675 901 participants; 5528 cases; median follow-up = 13 years). Frequent aspirin use was self-reported via repeat questionnaires. We examined multiple time-updated, lagged aspirin-exposure metrics and risk of ovarian cancer by using pooled logistic regression adjusted for time-updated confounders.

Results: While ever frequent aspirin use was not associated with ovarian cancer [odds ratio (OR) 0.97; 95% confidence interval (CI): 0.91-1.03], individuals who reported long-term use experienced a 14% reduction in ovarian cancer risk (>6 years; OR 0.86; 95% CI: 0.77-0.97). This risk reduction was evident among individuals with at least three ovarian cancer risk factors (OR 0.65; 95% CI: 0.50-0.85) but not among individuals with fewer than three ovarian cancer risk factors (OR 0.94; 95% CI: 0.82-1.08), P-interaction = .02). Reduced ovarian cancer risks were also observed for low-dose aspirin use (OR 0.90; 95% CI: 0.80-1.01 for ever low-dose use; OR 0.75; 95% CI: 0.56-0.99 for long-term low-dose use) but not ever regular-dose use (OR 1.09; 95% CI: 0.94-1.27).

Conclusion: Long-term use of aspirin, and particularly low-dose aspirin, is associated with lower ovarian cancer risk, especially among individuals with other established risk factors for ovarian cancer. Research should continue to explore the potential role of long-term, low-dose aspirin use for ovarian cancer primary prevention.

Background: A wildfire occurred in the Gyeongpo district of Gangneung city, South Korea, on 11 April 2023, lasting for 8 h and burning 300 acres. While previous studies have examined the health effects of major wildfires, research on short-lasting, small-scale wildfires remains scarce. By capitalizing on the timing of the wildfire as a natural experiment, we investigated the health effects of the Gangneung wildfire on residents living near the wildfire site.

Methods: The wildfire-exposed and control districts were determined based on satellite images of land damage. The weekly number of district-level cause-specific hospital visits was extracted from the National Health Insurance Database. The number of hospital visits for residents living in the exposed district was compared with that in 20 control districts by using the Generalized Synthetic Control Method. The excess number of visits attributable to the wildfire was estimated for periods of 0-3 and 0-7 weeks following the wildfire.

Results: Over 8 weeks following the wildfire, excess respiratory disease hospital visits {308.7 cases [95% confidence interval (CI): 119.7, 603.6]} were observed in residents of the exposed district, including cases of upper respiratory infections, influenza and pneumonia, and chronic lower respiratory diseases. Cardiovascular disease visits [83.3 cases (95% CI: 32.4, 136.0)] of the exposed district, notably for hypertensive disorders and ischemic heart diseases, increased for ≤4 weeks post-wildfire.

Conclusion: Excess respiratory and cardiovascular disease-related hospital visits were observed among residents living near the wildfire site. Even a small-scale wildfire may have health impacts on residents for >2 months.

Background: In the USA, racial disparities in blood pressure have persisted, with Black people experiencing a greater risk of hypertension compared with White people. While disparities in lead exposure may be related to some of this disparity, little is known about the mediating role of lead in racial disparities in blood pressure.

Methods: We used national-level, cross-sectional data of non-institutionalized US adults aged ≥20 years from the National Health and Nutrition Examination Survey (NHANES): NHANES-III (1988-1994) (n = 10 570) and NHANES 2017-2020 (n = 4536). We examined the extent to which racial disparities in blood pressure were mediated by disparities in blood lead levels between these two NHANES cycles by using causal mediation analysis. We estimated natural direct and indirect effects, and considered potential interaction between race and blood lead levels by using four-way decomposition.

Results: In NHANES-III, the Black participants would have a 5.74-mmHg (95% confidence interval: 4.94, 6.54) higher mean systolic blood pressure compared with White participants if all adjusted covariates were held equal to that of the White population; 10% of this disparity was mediated by differences in blood lead levels between Black and White participants. Similar trends were observed for hypertension. In NHANES 2017-2020, similar overall trends were observed. However, the proportion of racial disparities mediated by differences in blood lead levels between Black and White individuals reduced from 10% to 5%.

Conclusion: These findings suggest that racial differences in lead exposure may be related to racial disparities in blood pressure, but the mediating role of blood lead levels has decreased since the 1980s.

Background: Diagnostic self-testing for SARS-CoV-2 may lead to selection bias in test-negative case-control designs (TND) for COVID-19 vaccine effectiveness (VE) at the primary care level. We investigated whether SARS-CoV-2 self-testing among those with acute respiratory infection (ARI) after the acute pandemic phase was associated with primary care healthcare seeking in the general Dutch population.

Methods: We pooled questionnaire data from three study rounds (June 2022, November 2022, and April 2023) of the nationwide PIENTER Corona cohort study. Among 3152 participants aged ≥18 years, we selected the first self-reported ARI episode with cough, sore throat, dyspnoea, and/or coryza since March 2022. We performed log-binomial regression analyses adjusted for age, sex, education, and comorbidities to assess the associations between COVID-19 vaccination, SARS-CoV-2 self-testing, and general practitioner (GP) consultation, and between GP consultation and the prior self-test result.

Results: Vaccinated (vs. unvaccinated) participants with an ARI episode more often self-tested [adjusted risk ratio (RR) 1.13, 95% confidence interval (CI) 1.04-1.27]. Vaccination (RR 0.78, 95% CI 0.48-1.44) and the self-test result overall (RR 0.86, 95% CI 0.69-1.08) were both not associated with GP consultation. However, with point estimates in opposite directions, vaccinated individuals seemed less likely (RR 0.86, 95% CI 0.68-1.08) and unvaccinated seemed more likely (RR 1.57, 95% CI 0.36-6.28) to consult a GP after a positive self-test.

Conclusion: Findings from this Dutch-population-based cohort suggest that GP consultations between March 2022 and May 2023 may have differed by self-test result and vaccination status, indicating that selection bias in the TND COVID-19 VE estimates from testing before GP consultation could be a valid concern. More research in various settings is needed.

Background: Evidence of gastric cancer (GC) screening's impact on GC incidence remains limited. In 2002, South Korea started a nationwide GC screening program. This study uses a quasi-experimental design to evaluate the effect of the program on GC incidence in Seoul.

Methods: Using a flexible synthetic control method (SCM), we estimated the impact of GC screening on age-standardized GC incidence in Seoul. Annual age-specific GC incidence data were obtained from the Seoul Cancer Registry and Cancer Incidence in Five Continents Plus database. Post-intervention trends in GC incidence between Seoul and the synthetic control were compared to estimate average rate ratios (RRs) with 95% confidence intervals (CIs). Several sensitivity and alternative analyses were performed, including a modified age-period-cohort (APC) analysis.

Results: The screening program was associated with a higher GC incidence in Seoul compared to the synthetic control, with an average post-intervention RR of 1.11 (95% CI: 0.99-1.24). After 2002, the start of the screening program, there was a noticeable increase in the post-intervention differences between Seoul and the synthetic control, which peaked in 2011 (RR 1.26), and then began to fall. The results were robust across sensitivity analyses and alternative analyses. The modified APC analysis indicated that after initially expanding and then diminishing, the effect eventually reversed, resulting in a reduction in incidence.

Conclusions: These findings suggest that healthcare sectors should anticipate an immediate increase in care demands following GC screening implementation. While a subsequent reduction in GC incidence is expected, the potential preventive impact remains inconclusive.