Table 1 Sample size per group n(S, T) for ANCOVA model under \(\alpha =0.05\) and \(1-\beta =0.8\) with different number of pre-treatment and post-treatment measurements
From: The optimal pre-post allocation for randomized clinical trials
S, T | n(S, T) | Sample size reduction percentage (%) \(1-n(S,T)/n(1,1)\) |
|---|---|---|
\(S=1, T=1\) | \(n(1,1)=46\) | - |
\(S=2, T=1\) | \(n(2,1)=44\) | 4.3% |
\(S=1, T=2\) | \(n(1,2)=39\) | 15.2% |
\(S=1, T=4\) | \(n(1,4)=36\) | 21.7% |
\(S=2, T=3\) | \(n(2,3)=35\) | 23.9% |
\(S=2, T=4\) | \(n(2,4)=33\) | 28.3% |
\(S=4, T=2\) | \(n(4,2)=36\) | 21.7% |