I had a hard time finding autocorrelation published for mortality, so I used a conservative estimate. But there is some literature showing mortality highly autocorrelated, as much as .8-.95 depending on diagnosis. I ran a grid of more numbers for the exercise
| 80% power effect size | t-test sample size | Autocorrelation | ratio (indep design/ITS) | ITS sample size |
| 0.03 | 4524 | 0.95 | 1.38 | 3278 |
| 0.03 | 4524 | 0.8 | 0.55 | 8225 |
| 0.03 | 4524 | 0.5 | 0.54 | 8378 |
| 0.03 | 4524 | 0.25 | 0.71 | 6372 |
| 0.03 | 4524 | 0.05 | 0.93 | 4865 |
| 0.05 | 1630 | 0.95 | 1.38 | 1181 |
| 0.05 | 1630 | 0.8 | 0.55 | 2964 |
| 0.05 | 1630 | 0.5 | 0.54 | 3019 |
| 0.05 | 1630 | 0.25 | 0.71 | 2296 |
| 0.05 | 1630 | 0.05 | 0.93 | 1753 |