Showing papers by "Frank E. Speizer published in 2016"

Origin, Methods, and Evolution of the Three Nurses’ Health Studies

Abstract: We have summarized the evolution of the Nurses’ Health Study (NHS), a prospective cohort study of 121 700 married registered nurses launched in 1976; NHS II, which began in 1989 and enrolled 116 430 nurses; and NHS3, which began in 2010 and has ongoing enrollment.Over 40 years, these studies have generated long-term, multidimensional data, including lifestyle- and health-related information across the life course and an extensive repository of various biological specimens. We have described the questionnaire data collection, disease follow-up methods, biorepository resources, and data management and statistical procedures.Through integrative analyses, these studies have sustained a high level of scientific productivity and substantially influenced public health recommendations. We have highlighted recent interdisciplinary research projects and discussed future directions for collaboration and innovation.

Association Between Rotating Night Shift Work and Risk of Coronary Heart Disease Among Women

Abstract: Importance Prospective studies linking shift work to coronary heart disease (CHD) have been inconsistent and limited by short follow-up. Objective To determine whether rotating night shift work is associated with CHD risk. Design, Setting, and Participants Prospective cohort study of 189 158 initially healthy women followed up over 24 years in the Nurses’ Health Studies (NHS [1988-2012]: N = 73 623 and NHS2 [1989-2013]: N = 115 535). Exposures Lifetime history of rotating night shift work (≥3 night shifts per month in addition to day and evening shifts) at baseline (updated every 2 to 4 years in the NHS2). Main Outcomes and Measures Incident CHD; ie, nonfatal myocardial infarction, CHD death, angiogram-confirmed angina pectoris, coronary artery bypass graft surgery, stents, and angioplasty. Results During follow-up, 7303 incident CHD cases occurred in the NHS (mean age at baseline, 54.5 years) and 3519 cases in the NHS2 (mean age, 34.8 years). In multivariable-adjusted Cox proportional hazards models, increasing years of baseline rotating night shift work were associated with a significantly higher CHD risk in both cohorts. In the NHS, the age-standardized incidence rate (IR) for less than 5 years of rotating night shift work per 100 000 person-years was 435.1 (hazard ratio [HR], 1.02; 95% CI, 0.97-1.08); the IR for 5 to 9 years of rotating night shift work was 525.7 (HR, 1.12; 95% CI, 1.02-1.22); and the IR for 10 years or more of rotating night shift work was 596.9 (HR, 1.18; 95% CI, 1.10-1.26; P P = .01 for trend) vs an IR of 122.6 in women who never worked rotating night shifts. In the NHS, the association between duration of rotating night shift work and CHD was stronger in the first half of follow-up (IR for P P = .004 for trend; P = .02 for interaction), suggestive of waning risk after cessation of shift work. Longer time since quitting shift work was associated with decreased CHD risk among ever shift workers in the NHS2 ( P Conclusions and Relevance Among women who worked as registered nurses, longer duration of rotating night shift work was associated with a statistically significant but small absolute increase in CHD risk. Further research is needed to explore whether the association is related to specific work hours and individual characteristics.