EPI 390 Study Guide - Final Guide: Cohort Study, Odds Ratio, Relative Risk
Document Summary
Circumstance in which researchers lose contact with study participants, resulting in unavailable outcome data on those people. In a way based on theoretical deduction rather than empirical observation. Less time, money and size, yields the odds ratio. Nondiseased persons from whom the controls are selected may not be representative of the original cohort because of death or loss to follow up among cases. Establishes time sequence, avoids bias, several outcomes can be asssessed. Weaknesses of cohort study large samples often required, limited to one risk factor, not feasible with rare outcomes. Selecting people from the general population to act as controls. Hospitals, general population, special groups (family, relatives, friends). Differ from healthy people such that they do not accurately represent the exposure distribution in the population where cases were obtained. Represent the population from which cases were selected. More costly and time consuming, may be difficult to contact healhty people busy with work, pooreer recall than hospital controls, less motivated.
