POPM 3240 Lecture Notes - Lecture 18: Cohort Study, Recall Bias
27 Mar 2018
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Document Summary
Cohort = a group of subjects that has a defined characteristic in common. Selection depends on the exposure status (classified as e- and e+) All subjects must be d- at the beginning of the study. Follow groups over a predetermined time period to estimate incidence of disease in each exposure. Compare development of disease in e- and e+ Observational because investigator does not determine or allocate the exposure status. Select defined population prior to identifying exposure history. Different from cross-sectional that cs examining just a snapshot, has both d- and d+ individuals, and doesn"t necessarily need to have something in common. Follow e- and e+ forward in time from present to a predetermined endpoint in future. Follow-up can be to present say or more recent past records. Positive association between e and o meaning that we would expect the incidence of disease among the e+ group to be greater than the incidence of disease in the e- group.
