From: How many repeated measures in repeated measures designs? Statistical issues for comparative trials
pre | post | mix | Change from | Change to | Sample size reduction | ||
 |  |  | No. of baseline measures (p) | No. of follow-up measures (r) | No. of baseline measures (p) | No. of follow-up measures (r) |  |
0.7 | 0.7 | 0.5 | 1 | 1 | 1 | 4 | 30% |
 |  |  |  |  | 4 | 1 | 10% |
 |  |  |  |  | 4 | 4 | 40% |
 |  |  | 4 | 4 | 4 | 7 | 7% |
 |  |  |  |  | 7 | 4 | 3% |
 |  |  |  |  | 7 | 7 | 10% |
 |  |  | 7 | 7 | 7 | 14 | 5% |
 |  |  |  |  | 14 | 7 | 2% |
 |  |  |  |  | 14 | 14 | 8% |
 |  |  | 14 | 14 | 28 | 28 | 4% |
0.5 | 0.5 | 0.5 | 1 | 1 | 1 | 4 | 50% |
 |  |  |  |  | 4 | 1 | 20% |
 |  |  |  |  | 4 | 4 | 70% |
 |  |  | 4 | 4 | 4 | 7 | 24% |
 |  |  |  |  | 7 | 4 | 17% |
 |  |  |  |  | 7 | 7 | 40% |
 |  |  | 7 | 7 | 7 | 14 | 27% |
 |  |  |  |  | 14 | 7 | 22% |
 |  |  |  |  | 14 | 14 | 48% |
 |  |  | 14 | 14 | 28 | 28 | 49% |
0.9 | 0.9 | 0.8 | 1 | 1 | 1 | 4 | 21% |
 |  |  |  |  | 4 | 1 | 14% |
 |  |  |  |  | 4 | 4 | 35% |
 |  |  | 4 | 4 | 4 | 7 | 5% |
 |  |  |  |  | 7 | 4 | 3% |
 |  |  |  |  | 7 | 7 | 8% |
 |  |  | 7 | 7 | 7 | 14 | 3% |
 |  |  |  |  | 14 | 7 | 3% |
 |  |  |  |  | 14 | 14 | 6% |
 |  |  | 14 | 14 | 28 | 28 | 3% |