EPI 320 Lecture Notes - Lecture 18: Social Desirability Bias, Occupational Safety And Health, Recall Bias
Document Summary
Major categories and consequences of bias: selection bias, participant selection, participant retention, information bias and misclassification, interviewer bias, recall bias, reporting bias/social desirability bias. Information bias (aka observation: when exposure, outcome or confounder info is collected incorrectly, can come from interviewer, participant or test, results in misclassification = participants in wrong category for exposure, outcome or confounder impacts analysis. Differential vs. non-differential misclassification: non-diff: amount of misclassification is same between groups, differential: differs between groups, groups depend on study design: better/worse data on outcomes among the exposed (cohort/experimental) and exposure among cases (case control) Effects of exposure misclassification: non-diff misclassification of exposure bias towards the null, differential misclassification of exposure bias toward or away from null. Effects of outcome misclassification: non-diff undercounting of outcome = not affect assoc. 2: non-diff over counting will attenuate assoc, diff can bias toward or away from null.
