Healthcare workers may have different risk for severe outcomes compared with the general population during diverse crises. This paper introduces the concept of healthcare worker versus population hazard (HPH), the risk of an outcome of interest in active healthcare workers compared with the general population they serve. HPH can be expressed with relative risk (HPH(r)) and absolute risk difference

The Jiangsu Biobank for the Prevention and Control of Diabetes (JBPCD) is a community-based prospective cohort study initiated in Jiangsu province, to examine the burden of complications associated with type 2 diabetes mellitus (T2DM). This study aims to better understand the incidence, risk factors, and long-term outcomes of T2DM complications to inform prevention and control strategies. From October

Non-response to surveys is a common problem; even more so during the COVID-19 pandemic with social distancing measures challenging data collection. As respondents often differ from non-respondents, this can introduce bias. The goal of the current study was to see if we can reduce bias and restore sample representativeness in a series of COVID-19 surveys embedded within five UK cohort studies by using

The China Prospective Multi-Center Birth Cohort Study was launched in 2022. In collaboration with medical centers in 12 cities, it aims to establish a high-quality, multidimensional cohort comprising 20,000 natural pregnancy and assisted reproductive families. As of June 26, 2024, 12,911 pregnant women have participated in this study, and 161,122 biological samples have been collected. These samples

In causal inference, parametric models are usually employed to address causal questions estimating the effect of interest. However, parametric models rely on the correct model specification assumption that, if not met, leads to biased effect estimates. Correct model specification is challenging, especially in high-dimensional settings. Incorporating Machine Learning (ML) into causal analyses may reduce

This study evaluated the relationship between Covid-19 vaccination and menstrual bleeding disturbances using a large national registry linkage including 666,467 women between 20 and 40 years of age residing in Norway on January 1st, 2019. Information on vaccination—BNT162b2 and mRNA-1273 — was obtained from the Norwegian vaccination registry. Diagnoses of menstrual disturbances (absent/scanty, excessive

Results from studies investigating the association between maternal or child epilepsy, use of anticonvulsants in pregnancy, and childhood cancer are inconsistent and at times contradictory. Linking Danish national databases, we obtained epilepsy and childhood cancer diagnoses, and anticonvulsant use data. We estimated adjusted odds ratios of all or specific childhood cancers in relation to maternal

Emerging evidence has shown the association between female reproductive histories (e.g., menarche age, parity, premature and early menopause) and the risk of dementia. However, little attention has been given to infertility and pregnancy loss. To examine the associations of infertility, recurrent miscarriages, and stillbirth with the risk of dementia, this study used data from four cohorts in the International

Trial emulations in observational data analyses can complement findings from randomized clinical trials, inform future trial designs, or generate evidence when randomized studies are not feasible due to resource constraints and ethical or practical limitations. Importantly, trial emulation designs facilitate causal inference in observational data analyses by enhancing counterfactual thinking and comparisons

Investigators often believe that relative effect measures conditional on covariates, such as risk ratios and mean ratios, are “transportable” across populations. Here, we examine the identification of causal effects in a target population using an assumption that conditional relative effect measures are transportable from a trial to the target population. We show that transportability for relative