Table IV.
Simulation comparing BDOGS, O’Brien–Fleming (OF*), and generalized gamma (GG*) designs in a clinical trial with five analyses, size=0.05, and power=0.80. OF* decision boundaries were obtained using East assuming a piece-wise constant hazard. GG* assumes a GG likelihood and has one set of decision boundaries.
| True hazard |
Method | False pos. |
Power | Sample size, δ =0 (δ=3)
|
|||||
|---|---|---|---|---|---|---|---|---|---|
| Mean | 2.5 per cent | 25 per cent | 50 per cent | 75 per cent | 97.5 per cent | ||||
| Proportional hazards assumption met | |||||||||
| Exp | BDOGS | 0.05 | 0.80 | 603 (671) | 285 (300) | 320 (334) | 624 (651) | 646 (865) | 1167 (1204) |
| OF* | 0.05 | 0.99 | 1399 (1220) | 836 (842) | 1159 (902) | 1650 (1187) | 1650 (1650) | 1650 (1650) | |
| GG* | 0.01 | 0.65 | 806 (1465) | 593 (633) | 623 (1216) | 645 (1650) | 857 (1650) | 1650 (1650) | |
| Robustness study—proportional hazards assumption not met | |||||||||
| WI | BDOGS | 0.05 | 0.80 | 310 (336) | 275 (292) | 291 (308) | 300 (317) | 309 (328) | 578 (609) |
| OF* | 0.05 | 0.99 | 1378 (731) | 787 (582) | 1106 (605) | 1650 (794) | 1650 (818) | 1650 (1128) | |
| GG* | 0.01 | 0.65 | 381 (1400) | 276 (314) | 294 (1132) | 305 (1650) | 570 (1650) | 606 (1650) | |
| PI | BDOGS | 0.02 | 0.80 | 288 (329) | 266 (281) | 279 (297) | 287 (307) | 295 (318) | 314 (506) |
| OF* | 0.05 | 0.99 | 1371 (593) | 773 (562) | 1090 (579) | 1650 (587) | 1650 (596) | 1650 (785) | |
| GG* | 0.01 | 0.56 | 301 (1406) | 264 (301) | 280 (1119) | 288 (1650) | 297 (1650) | 570 (1650) | |
| VS | BDOGS | 0.05 | 0.96 | 365 (322) | 264 (281) | 280 (297) | 291 (306) | 556 (316) | 585 (593) |
| OF* | 0.05 | 0.99 | 1378 (671) | 773 (567) | 1091 (586) | 1650 (600) | 1650 (794) | 1650 (828) | |
| GG* | 0.00 | 0.94 | 461 (1181) | 267 (306) | 288 (804) | 558 (1120) | 572 (1650) | 599 (1650) | |
| LN2 | BDOGS | 0.05 | 0.80 | 1311 (1463) | 646 (319) | 949 (1337) | 1307 (1650) | 1650 (1650) | 1650 (1650) |
| OF* | 0.04 | 0.68 | 1459 (1515) | 927 (949) | 1292 (1335) | 1650 (1650) | 1650 (1650) | 1650 (1650) | |
| GG* | 0.05 | 0.80 | 1333 (1507) | 669 (710) | 954 (1350) | 1310 (1650) | 1650 (1650) | 1650 (1650) | |
| WD | BDOGS | 0.05 | 0.80 | 1028 (1050) | 315 (302) | 665 (667) | 895 (915) | 1230 (1650) | 1650 (1650) |
| OF* | 0.05 | 0.92 | 1409 (1350) | 850 (860) | 1176 (1188) | 1650 (1217) | 1650 (1650) | 1650 (1650) | |
| GG* | 0.01 | 0.67 | 911 (1468) | 610 (643) | 638 (1219) | 850 (1650) | 1166 (1650) | 1650 (1650) | |
| PD | BDOGS | 0.05 | 0.80 | 1005 (1165) | 298 (309) | 666 (703) | 905 (1273) | 1248 (1650) | 1650 (1650) |
| OF* | 0.05 | 0.98 | 1438 (1392) | 891 (917) | 1239 (1270) | 1650 (1299) | 1650 (1650) | 1650 (1650) | |
| GG* | 0.01 | 0.76 | 1124 (1480) | 639 (679) | 888 (1294) | 1199 (1650) | 1272 (1650) | 1650 (1650) | |