Table 1:
Summary of simulation parameters; all parameter sets use an error standard deviation of one with 10,000 simulations.
| Mean difference between groups (τ) | Percentage censored | N per Arma | R2: Median (IQR)b |
|---|---|---|---|
| 0.00 | 10 | 300 | 0.0008 (0.0002, 0.0022) |
| 0.00 | 30 | 300 | 0.00 (0.00, 0.00) |
| 0.00 | 50 | 300 | 0.00 (0.00, 0.00) |
| 0.00 | 70 | 300 | 0.00 (0.00, 0.00) |
| 0.00 | 90 | 300 | 0.00 (0.00, 0.00) |
| −0.25 | 10 | 250 | 0.02 (0.01, 0.02) |
| −0.25 | 30 | 244 | 0.02 (0.01, 0.02) |
| −0.25 | 50 | 274 | 0.02 (0.01, 0.02) |
| −0.25 | 70 | 357 | 0.02 (0.01, 0.02) |
| −0.25 | 90 | 717 | 0.02 (0.01, 0.02) |
| −0.50 | 10 | 64 | 0.06 (0.04, 0.09) |
| −0.50 | 30 | 62 | 0.06 (0.04, 0.09) |
| −0.50 | 50 | 70 | 0.06 (0.04, 0.09) |
| −0.50 | 70 | 93 | 0.06 (0.04, 0.08) |
| −0.50 | 90 | 195 | 0.06 (0.04, 0.08) |
| −0.75 | 10 | 30 | 0.13 (0.08, 0.18) |
| −0.75 | 30 | 29 | 0.13 (0.08, 0.19) |
| −0.75 | 50 | 33 | 0.13 (0.08, 0.18) |
| −0.75 | 70 | 44 | 0.13 (0.09, 0.17) |
| −0.75 | 90 | 100 | 0.13 (0.10, 0.15) |
| −1.00 | 10 | 17 | 0.21 (0.14, 0.30) |
| −1.00 | 30 | 17 | 0.21 (0.14, 0.30) |
| −1.00 | 50 | 20 | 0.21 (0.14, 0.29) |
| −1.00 | 70 | 27 | 0.21 (0.15, 0.27) |
| −1.00 | 90 | 68 | 0.20 (0.17, 0.24) |
a
Sample sizes for each value of τ > 0 and rate of censoring were determined using Lachenbruch’s62 formula. When τ = 0, the expected power is the type I error rate of 0.05 and the sample size was set at 300.
b
R2 calculated by using simulated data prior to censoring with standard R2 formula of simple linear regression.