Table 1.
Trial HRs vs. EC HRs
| Analysis | RCT | EC analysis | RCT HR (95% CI) | EC adjusted HR (95% CI) | Difference ln(HR) | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Exp. arm | Control arm | Exp. arm (RCT) | Control arm (EHR) | ||||||||
| N | E | N | E | N | E | N | E | ||||
| [1] NCT02008227 | 425 | 271 | 425 | 298 | 396 | 259 | 482 | 398 | 0.73 (0.62−0.86) | 0.71 (0.59−0.84) | 0.028 (−0.132, 0.188) |
| [2] NCT01903993 | 144 | 78 | 143 | 95 | 129 | 74 | 401 | 314 | 0.72 (0.54−0.98) | 0.66 (0.50−0.88) | 0.087 (−0.176, 0.350) |
| [3] NCT02366143 | 356 | 144 | 336 | 166 | 319 | 135 | 556 | 365 | 0.77 (0.61−0.96) | 0.75 (0.59−0.94) | 0.026 (−0.179, 0.231) |
| [4] NCT01351415 | 245 | 194 | 240 | 193 | 229 | 182 | 363 | 295 | 0.88 (0.74−1.04) | 0.89 (0.75−1.05) | −0.011 (−0.202, 0.179) |
| [5] NCT01493843: Arm A vs. B | 126 | 79 | 125 | 60 | 104 | 63 | 847 | 612 | 1.03 (0.75−1.41) | 0.95 (0.68−1.33) | 0.081 (−0.175, 0.337) |
| [6] NCT01493843: Arm C vs. D | 79 | 59 | 79 | 43 | 62 | 47 | 785 | 592 | 1.04 (0.72−1.50) | 1.07 (0.78−1.49) | −0.028 (−0.319, 0.262) |
| [7] NCT01493843: Arm E vs. F | 62 | 42 | 30 | 13 | 39 | 30 | 616 | 470 | 1.27 (0.75−2.15) | 1.32 (0.90−1.93) | −0.039 (−0.389, 0.312) |
| [8] NCT01519804 | 55 | 36 | 54 | 33 | 47 | 28 | 1,375 | 735 | 0.89 (0.55−1.46) | 1.43 (0.97−2.09) | −0.474 (−0.835, −0.114) |
| [9] NCT01496742: Cohort 1 | 69 | 32 | 70 | 29 | 59 | 21 | 834 | 464 | 1.38 (0.75−2.56) | 1.26 (0.80−1.97) | 0.091 (−0.310, 0.492) |
| [10] NCT01496742: Cohort 2 | 59 | 37 | 61 | 36 | 47 | 22 | 2,899 | 1,619 | 1.15 (0.68−2.56) | 1.11 (0.73−1.70) | 0.035 (−0.332, 0.403) |
| [11] NCT01366131 | 52 | 24 | 52 | 18 | 46 | 15 | 761 | 577 | 1.08 (0.52−2.21) | 0.90 (0.53−1.51) | 0.182 (−0.276, 0.640) |
CI, confidence interval; E, number of events (deaths); EC, external control; EHR, electronic health record; Exp., experimental; HR, hazard ratio; ln(HR), natural log hazard ratio; N, number of patients at risk; RCT, randomized controlled trial.