Objectives Lecture 7 · p.2 Understand the major systematic errors in clinical (and preclinical research)
Topics 0 of 12 done Study designs primerp.3–8, 70–71 · First look done example progress, not yours What is systematic errorp.9–12, 72–73 · Not started Confoundingp.13–21, 74–75 · Not started Confounder, mediator, moderatorp.22–29, 76–77 · Not started Selection biasp.30–33, 78–79 · Not started Classification of interventionsp.34–37, 80–81 · Not started Deviations from intended interventionsp.38–46, 82–85 · Not started Missing datap.47–53 · Not started Measurement of outcomesp.54–60, 86–87 · Not started Selection of the reported resultp.61–64, 88–89 · Not started Decision flowchartsp.65–66 · Not started Risk-of-bias toolsp.67–68 · Not started
Slide errata 3 L7 p.66 · Slide error
The flowchart diamond has a double negative ('Not because the participant did not receive the intervention as planned'), so its branches read inverted.
How the app teaches it: Use the RC8-consistent logic: excluded because the intervention wasn't received as planned → bias due to deviations from intended interventions; otherwise → bias due to missing data.
Decision flowcharts · Deviations from intended interventions · Missing data
L7 p.53 vs p.65 vs p.47 · Tension with standard theory
Is excluding early deaths after treatment starts missing data (p.47's near-identical example) or selection bias (p.32 definition and the p.65 flowchart branch 'initial follow-up period is missing')?
what the exam expects:Bias due to missing data.
How the app teaches it: Follow p.47: bias due to missing data. This matches Mock Q4, where selection bias isn't offered.
Missing data · Selection bias · Decision flowcharts
L7 Reality Check 6 (p.81) · Slide error
The answer slide reads 'Bias in measurement of intervention', which isn't among the options.
what the exam expects:Bias in classification of interventions.
How the app teaches it: It means bias in classification of interventions (recall of past exposure in a case-control design, as on L7 p.35).
Classification of interventions