Lesson 1 · Randomized Controlled Trials · Step 1 of 7
Why randomize?
In the 1970s, diarrheal disease killed an estimated 4 to 5 million children a year, and the treatment that worked needed a hospital. Randomized trials in Dhaka showed that a solution of salt, sugar and clean water could replace IV fluids for most children, and oral rehydration therapy is now credited with more than 50 million lives. Randomization is what made that evidence trustworthy. Assigning by chance balances the groups, on average, on everything, including factors nobody thought to measure. Matching can only balance the variables you know about.
Also covered: random assignment · confounding · oral rehydration therapy · history of the RCT
Alongside this step
- Slides and transcript — the whole video
- Read the chapter — Randomized Controlled Trials
Lesson 1 · 7 steps
1Why randomize?6:482Designing a trial: the question, the participants, and the allocation7:213Blinding, and what the control group receives6:054When is it ethical to randomize?6:075Running the trial: fidelity, monitoring, and reporting7:156After randomization: attrition, non-compliance, and spillover7:487From a trial result to policy8:38
Research Designs · lesson 1 of 5