title: The importance of post hoc approaches for overcoming non-response and attrition bias in population-sampled studies.
abstract: Population-based health studies are critical resources for monitoring population health and related factors such as substance use, but reliable inference can be compromised in various ways. Non-response and attrition are major methodological problems which reduce power and can hamper the generalizability of findings if individuals who participate and who remain in a study differ systematically from those who do not. In this issue of SPPE, McCabe et al. studied participants of the 2001-2002 National Epidemiologic Survey on Alcohol and Related Conditions, comparing attrition in Wave 2 across participants with different patterns of substance use at Wave 1. The implications of differential follow-up and further possibilities for addressing selective participation are discussed.
authors.affiliation: MRC/CSO Social and Public Health Sciences Unit, University of Glasgow, 200 Renfield Street, Glasgow, G2 3QB, UK. Linsay.Gray@glasgow.ac.uk.
authors.forename: Linsay
authors.initials: L
authors.lastname: Gray
mesh_terms: D015982:Bias; D015340:Epidemiologic Research Design; D005500:Follow-Up Studies; D006801:Humans; D019966:Substance-Related Disorders / Q000453:epidemiology*
keywords: Attrition; Bias; Non-response; Population based; Substance use