G D Batty1, C R Gale. 1. Medical Research Council Social and Public Health Sciences Unit, University of Glasgow, Glasgow, UK. david-b@sphsu.mrc.ac.uk
Abstract
BACKGROUND: Selection bias in observational epidemiology--the notion that people who participate in a study are fundamentally different from those who do not--is a perennial concern. In cohort studies, a potentially important but little investigated manifestation of selection bias is the distortion of the exposure-disease relationship according to participation status. METHODS: Seven years after the original UK Health and Lifestyle Survey (HALS1; N = 6484), attempts were made to resurvey participants (HALS2). The baseline characteristics, mortality experience following the completion of HALS2 and, finally, the baseline risk factor-cardiovascular disease (CVD) mortality gradients in HALS2 non-participants (N = 1894) and participants (N = 4590) were compared. RESULTS: Resurvey non-participants, based on data from HALS1, were younger, were of lower social class and had a lower prevalence of hypertension or self-reported limiting long-standing illness, but a higher prevalence of psychological distress (p < or = 0.027). The risk of death from future CVD was significantly higher in those baseline study members who did not participate in HALS2. However, the magnitude of the association between a series of risk factors and CVD mortality was essentially the same in the HALS2 non-participants and participants (p value for interaction > or = 0.108). CONCLUSION: In the present cohort study, non-response at resurvey did not bias the observed associations between baseline risk factors and later CVD mortality. Future studies should also examine the impact of non-response to baseline surveys on these relationships.
BACKGROUND: Selection bias in observational epidemiology--the notion that people who participate in a study are fundamentally different from those who do not--is a perennial concern. In cohort studies, a potentially important but little investigated manifestation of selection bias is the distortion of the exposure-disease relationship according to participation status. METHODS: Seven years after the original UK Health and Lifestyle Survey (HALS1; N = 6484), attempts were made to resurvey participants (HALS2). The baseline characteristics, mortality experience following the completion of HALS2 and, finally, the baseline risk factor-cardiovascular disease (CVD) mortality gradients in HALS2 non-participants (N = 1894) and participants (N = 4590) were compared. RESULTS: Resurvey non-participants, based on data from HALS1, were younger, were of lower social class and had a lower prevalence of hypertension or self-reported limiting long-standing illness, but a higher prevalence of psychological distress (p < or = 0.027). The risk of death from future CVD was significantly higher in those baseline study members who did not participate in HALS2. However, the magnitude of the association between a series of risk factors and CVD mortality was essentially the same in the HALS2 non-participants and participants (p value for interaction > or = 0.108). CONCLUSION: In the present cohort study, non-response at resurvey did not bias the observed associations between baseline risk factors and later CVD mortality. Future studies should also examine the impact of non-response to baseline surveys on these relationships.
Authors: Zihe Zheng; Casey M Rebholz; Kunihiro Matsushita; Judith Hoffman-Bolton; Michael J Blaha; Elizabeth Selvin; Lisa Wruck; A Richey Sharrett; Josef Coresh Journal: Ann Epidemiol Date: 2020-04-03 Impact factor: 3.797
Authors: Alyson J Littman; Edward J Boyko; Isabel G Jacobson; Jaime Horton; Gary D Gackstetter; Besa Smith; Tomoko Hooper; Timothy S Wells; Paul J Amoroso; Tyler C Smith Journal: BMC Med Res Methodol Date: 2010-10-21 Impact factor: 4.615
Authors: Léopold K Fezeu; G David Batty; David G Batty; Catharine R Gale; Mika Kivimaki; Serge Hercberg; Sebastien Czernichow Journal: PLoS One Date: 2015-05-18 Impact factor: 3.240
Authors: Beverly A Roberts; G David Batty; Catharine R Gale; Ian J Deary; Louise Parker; Mark S Pearce Journal: Atherosclerosis Date: 2013-10-02 Impact factor: 5.162