title: Sources of bias in retrospective cohort mortality studies: a note on treatment of subjects lost to follow-up.
abstract: The three important sources of bias in retrospective cohort mortality studies are: the healthy worker confounding bias, the lost to follow-up bias, and bias due to methods of follow-up that result in underascertainment of deaths. This paper presents how the treatment of the lost to follow-up impacts ultimately on the apparent forces of mortality in a cohort. The findings are discussed in the context of the other sources of bias. The treatment of subjects lost to follow-up as lost at the time of loss offers the best estimate of expected mortality and should be the preferred approach.
mesh_terms: D000367:Age Factors; D004812:Epidemiologic Methods; D005500:Follow-Up Studies; D006801:Humans; D009111:Local Government; D008297:Male; D009518:New York; D009784:Occupational Diseases / Q000401:mortality*; D012189:Retrospective Studies; D013997:Time Factors