34:40Selection Bias | Understanding Medical Research
From the creator
Selection bias is what happens when the people in a study are no longer the people you actually want to know about, and unlike confounding it cannot be adjusted away. This video covers online polls, low response rates, the healthy worker effect, loss to follow-up, and why intention to treat is the standard for randomized trials. Chapters: 00:00 Bias in the statistical sense 01:40 Bias versus confounding 02:46 Toward or away from the null 03:51 What selection bias is 04:45 Polls and survey response rates 07:25 The healthy worker effect 08:25 Loss to follow-up 11:52 Per-protocol versus intention to treat 14:47 Take-home points Learning objectives: After watching, you'll be able to: - Distinguish bias from confounding and explain why bias cannot be adjusted away once the data are collected - Identify selection bias in online polls, low-response surveys, and studies with differential loss to follow-up - Explain why intention-to-treat analysis, not per-protocol analysis, is the standard for randomized trials 📺 Watch the full playlist on YouTube: https://www.youtube.com/playlist?list=PLh9mgdi4rNewVyTec_MVGxIbNSEeMhEsZ 🎓 Enroll on Coursera for assessments and a certificate: https://www.coursera.org/learn/medical-research 🌐 Explore more learning opportunities on Yale Online: https://online.yale.edu/courses/understanding-medical-research-your-facebook-friend-wrong
Published 2020-07-31 · Watch on YouTube ↗
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