Abstract Background Epidemiological studies have shown inconsistent results regarding the link between smoking and breast cancer risk, despite the biological plausibility of a positive association. Methods Participants were 166 611 women from nine prospective cohort studies in Japan which launched in 1984–1994 and followed for 8–22 years. Information on smoking and secondhand smoke was obtained through self-administered baseline questionnaires. Breast cancer was defined as code C50 according to the International Classification of Diseases for Oncology, 3rd Edition or the International Classifi ..read more

Mendelian randomizationassumptionsinstrumental variableindependence assumptionpopulation stratificationassortative mating ..read more

Australiahousehold panel studylongitudinal surveyspublic health ..read more

Abstract Background Over 120 million people in the USA live in areas with unsafe ozone (O3) levels. Studies among adults have linked exposure to worse lung function and higher risk of asthma and chronic obstructive pulmonary disease (COPD). However, few studies have examined the effects of O3 in children, and existing studies are limited in terms of their geographic scope or outcomes considered. Methods We leveraged a dataset of encounters at 42 US children’s hospitals from 2004–2015. We used a one-stage case-crossover design to quantify the association between daily maximum 8-hour O3 in the c ..read more

Abstract Background Studying the causes of death among deceased spouses and surviving partners may provide insights into the underlying mechanisms of the association between widowhood and mortality. This study investigated the mortality risk of widowhood in Taiwan, examined the association of the cause of death between widowed individuals and their deceased spouses and explored potential modifying effects by age, gender and duration after widowhood. Methods This matched cohort study utilized Taiwan's National Health Insurance claims database and National Death Registry. In total, 204 010 widow ..read more

Early childhood exposurematernal and child healthmedicationsperinatal exposurereal-world data linkageeducation and social services ..read more

Causal inferencemediationraceethnicityinequity ..read more

Sri Lankaageingcohortbiobanknon-communicable diseasemental healthhealth care usepublic opinion ..read more

Abstract Background A growing body of evidence has reported positive associations between long-term exposure to air pollution and poor COVID-19 outcomes. Inconsistent findings have been reported for short-term air pollution, mostly from ecological study designs. Using individual-level data, we studied the association between short-term variation in air pollutants [nitrogen dioxide (NO2), particulate matter with a diameter of <2.5 µm (PM2.5) and a diameter of <10 µm (PM10) and ozone (O3)] and hospital admission among individuals diagnosed with COVID-19. Methods The COVAIR-CAT (Air polluti ..read more

Abstract Background Rising midlife mortality in the USA has raised concerns, particularly the increase in ‘deaths of despair’ (due to drugs, alcohol and suicide). Life expectancy is also stalling in other countries such as the UK, but how trends in midlife mortality are evolving outside the USA is less understood. We provide a synthesis of cause-specific mortality trends in midlife (25–64 years of age) for the USA and the UK as well as other high-income and Central and Eastern European (CEE) countries. Methods We document trends in midlife mortality in the USA, UK and a group of 13 high-i ..read more