Table 1 Sample Size Calculation
From: Physical activity as a treatment for depression: the TREAD randomised trial protocol
total N randomised | N for primary analysis | power for 60% vs. 73% (OR = 1.80) 1 | power for 20% vs. 33% (OR = 1.97) 2 | detectable difference with 80% power 3 | power to detect 3 BDI point difference |
|---|---|---|---|---|---|
360 | 306 | 63% | 69% | 15% | 82% |