International journal of epidemiology最新文献

Background: Colorectal cancer remains a major global public health challenge. Its incidence is shaped by a complex interplay of screening programmes and age, period and cohort factors.

Methods: We introduce a novel Age-Period-Cohort-Screening (APCS) model to analyse trends in colorectal cancer incidence in Taiwan from 2000 to 2019.

Results: In 2010, the incidence of colorectal cancer in Taiwan increased by 19.2% (95% CI: 13.5%, 25.3%) for men and 15.6% (95% CI: 9.2%, 22.4%) for women. This was followed by annual declines of 3.4% (95% CI: 2.8%, 4.1%) and 3.1% (95% CI: 2.4%, 3.9%), respectively. By 2015 for men and 2014 for women, the age-standardized incidence had fallen below the levels projected in a no-screening scenario. By 2019, the incidence had further declined by 12.4% (95% CI: 11.8%, 13.1%) for men and 11.6% (95% CI: 10.7%, 12.6%) for women, compared with the no-screening scenario. Cohort effects have shown a persistent rise from 1920 to 1980: incidence increased 5.8-fold for men and 3.1-fold for women. The trend began to plateau after 1980, with a noticeable decline in women.

Conclusion: Through its screening programme, Taiwan has successfully reduced colorectal cancer incidence by 10% as of 2019. Furthermore, the incidence due to cohort effects has plateaued and even begun to decline. However, continued monitoring remains crucial. The advanced APCS model could serve as a robust analytical tool for other researchers and policy makers evaluating the impacts of cancer screening programmes on incidence trends.

Background: Published analyses of prostate cancer nested case-control and survival data in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study cohort suggested that men with higher baseline vitamin D [25(OH)D] concentrations have both (i) increased prostate cancer risk and (ii) decreased prostate cancer-specific fatality.

Methods: To investigate possible factors responsible for a spurious association with prostate cancer fatality, we reanalysed baseline serum vitamin D associations with prostate cancer risk and prostate cancer-specific fatality in case-control data nested within the ATBC Study (1000 controls and 1000 incident prostate cancer cases). Conditional logistic regression and Cox proportion hazard models were used, respectively, to estimate odds ratios for risk and hazard ratios for prostate cancer-specific fatality, overall and by disease aggressiveness. We replicated these case-control analyses using baseline serum measurements of alpha-tocopherol (vitamin E), beta-carotene and retinol (vitamin A), and used the entire ATBC Study cohort (n = 29 085) to estimate marginal associations between these baseline vitamins and prostate cancer incidence and fatality following blood collection.

Results: Vitamin D analyses agreed closely with those originally published, with opposite risk and fatality associations. By contrast, the analyses of alpha-tocopherol, beta-carotene and retinol yielded concordant associations for prostate cancer incidence and prostate cancer-specific fatality.

Conclusions: We found evidence of neither artefacts in the nested prostate cancer case-control data set nor detection or collider biases in the fatality analyses. The present findings therefore support a valid inverse (i.e. beneficial) association between vitamin D and prostate cancer-specific survival that warrants further evaluation, including possibly in controlled trials.

Background: Higher body mass index (BMI) is associated with higher incidence of cardiovascular and some non-cardiovascular diseases (CVDs/non-CVDs). However, uncertainty remains about its associations with mortality, particularly at lower BMI levels.

Methods: The prospective China Kadoorie Biobank recruited >512 000 adults aged 30-79 years in 2004-08 and genotyped a random subset of 76 000 participants. In conventional and Mendelian randomization (MR) analyses, Cox regression yielded adjusted hazard ratios (HRs) associating measured and genetically predicted BMI levels with incident risks of major vascular events (MVEs; conventional/MR 68 431/23 621), ischaemic heart disease (IHD; 50 698/12 177), ischaemic stroke (IS; 42 427/11 897) and intracerebral haemorrhage (ICH; 7644/4712), and with mortality risks of CVD (15 427/6781), non-CVD (26 915/4355) and all causes (42 342/6784), recorded during ∼12 years of follow-up.

Results: Overall, the mean BMI was 23.8 (standard deviation: 3.2) kg/m2 and 13% had BMIs of <20 kg/m2. Measured and genetically predicted BMI showed positive log-linear associations with MVE, IHD and IS, but a shallower positive association with ICH in conventional analyses. Adjusted HRs per 5 kg/m2 higher genetically predicted BMI were 1.50 (95% CI 1.41-1.58), 1.49 (1.38-1.61), 1.42 (1.31-1.54) and 1.64 (1.58-1.69) for MVE, IHD, IS and ICH, respectively. These were stronger than associations in conventional analyses [1.21 (1.20-1.23), 1.28 (1.26-1.29), 1.31 (1.29-1.33) and 1.14 (1.10-1.18), respectively]. At BMIs of ≥20 kg/m2, there were stronger positive log-linear associations of BMI with CVD, non-CVD and all-cause mortality in MR than in conventional analyses.

Conclusions: Among relatively lean Chinese adults, higher genetically predicted BMI was associated with higher risks of incident CVDs. Excess mortality risks at lower BMI in conventional analyses are likely not causal and may reflect residual reverse causality.

Background: The impact of migration on HIV risk among non-migrating household members is poorly understood. We measured HIV incidence among non-migrants living in households with and without migrants in Uganda.

Methods: We used four survey rounds of data collected from July 2011 to May 2018 from non-migrant participants aged 15-49 years in the Rakai Community Cohort Study. Non-migrants were individuals with no-migration between surveys or at the prior survey. Household migration was defined as ≥1 household member migrating into or out of the house from another community between surveys (∼18 months). Incident HIV was defined as testing HIV seropositive following a negative result. Incidence rate ratios (IRRs) were estimated using Poisson regression with generalized estimating equations. Analyses were stratified by gender, migration into or out of the household and the relationship between non-migrants and migrants (e.g. spouse, child).

Results: About 11 318 non-migrants (5674 women) were followed for 37 320 person-years. Twenty-eight percent (6059/21 370) of non-migrant person-visits had recent migration into or out of the household, and 240 HIV incident cases were identified. Overall, non-migrants in migrant households were not at greater risk of acquiring HIV than non-migrants in households without any migration. However, men were significantly more likely to acquire HIV if their spouse had recently migrated in [adjusted IRR: 2.12; 95% confidence interval (CI): 1.05-4.27] or out (adjusted IRR: 4.01; 95% CI, 2.16-7.44) compared with men with no spousal migration.

Conclusions: HIV incidence is higher among non-migrant men with migrant spouses. Targeted HIV testing and prevention interventions like pre-exposure prophylaxis could be considered for men with migrant spouses.

Background: The healthy worker effect may distort the association between exposure and health effects in workers. However, few studies have investigated both the healthy worker hire and survival effects simultaneously, and they are limited to mortality studies in male workers.

Methods: We utilized a data set comprising South Korean diagnostic medical radiation workers registered in the National Dose Registry between 1996 and 2011, and merged it with mortality and cancer incidence data. Standardized mortality ratios (SMRs) and standardized incidence ratios (SIRs) were computed for comparison with the general population. To account for time-varying confounders influenced by prior occupational radiation exposure, we applied g-estimation using structural nested accelerated failure time models and compared the outcomes with those from Weibull regression.

Results: A total of 1831 deaths and 3759 first primary cancer cases were identified among 93 918 workers. Both male (SMR = 0.44; 95% CI: 0.42, 0.46) and female workers (SMR = 0.53; 95% CI: 0.46, 0.60) showed lower mortality rates compared with national rates. In the SIR analysis, male workers exhibited reduced risks of solid cancer whereas female workers had increased risks. The g-estimation-derived hazard ratios (HRs) from radiation exposure exceeded those from Weibull regression estimates for all-cause death (HR = 2.55; 95% CI: 1.97, 3.23) and all-cancer incidence (HR = 1.96; 95% CI: 1.52, 2.55) in male workers whereas female workers showed the opposite results.

Conclusions: Comprehensive consideration of the healthy worker effect by sex is essential for estimating the unbiased impact of occupational exposure on health outcomes, notably in studies focusing on male mortality.

Background: This study aimed to estimate population-level and state-level lead-attributable mortality burdens stratified by socioeconomic status (SES) class in the USA.

Methods: Based on the National Health and Nutrition Examination Survey (NHANES), we constructed individual-level SES scores from income, employment, education and insurance data. We assessed the association between the blood lead levels (BLL) and all-cause mortality by Cox regression in the NHANES cohort (n = 31 311, 4467 deaths). With estimated hazard ratios (HR) and prevalences of medium (2-5 μg/dL) and high (≥ 5 μg/dL) BLL, we computed SES-stratified population-attributable fractions (PAFs) of all-cause mortality from lead exposure across 1999-2019. We additionally conducted a systematic review to estimate the lead-attributable mortality burden at state-level.

Results: The HR for every 2-fold increase in the BLL decreased from 1.23 (1.10-1.38) for the lowest SES class to 1.05 (0.90-1.23) for the highest SES class. Across all SES quintiles, medium BLL exhibited a greater mortality burden. Individuals with lower SES had higher lead-attributable burdens, and such disparities haver persisted over the past two decades. In 2017-19, annually 67 000 (32 000-112 000) deaths in the USA were attributable to lead exposure, with 18 000 (2000-41 000) of these deaths occurring in the lowest SES class. Substantial disparities in the state-level mortality burden attributable to lead exposure were also highlighted.

Conclusions: These findings suggested that disparities in lead-attributable mortality burden persisted within US adults, due to heterogeneities in the effect sizes of lead exposure as well as in the BLL among different SES classes.