Table 3 Reported and recalculated NNTs with 95% confidence intervals (CIs) from 17 studies using inappropriate methods to calculate NNTs for time-to-event data
From: Calculation of NNTs in RCTs with time-to-event outcomes: A literature review
No. | Reported NNT | Reported 95% CI | Recalculated NNT | Recalculated 95% CI | Absolute difference (reported NNT – recalculated NNT) |
|---|---|---|---|---|---|
1 | 14 | - | 17.5 | 9.2 – 171.9 | -3.5 |
2 | 23 | - | 18.2 | 11.1 – 49.6 | +4.8 |
3 | 10 | - | 14.7 | 7.8 – 117.6 | -4.7 |
4 | 40 | - | 57.1 | NNTB 24.2 to ∞ to NNTH 156.6 | -17.1 |
5 | O1: 2.2 O2: 6.1 | - | O1: 2.0 O2: 4.5 | O1: 1.7 – 2.7 O2: 2.8 – 15 | O1: +0.2 O2: +1.6 |
6 | TP1: 5–6 TP2: 12 | TP1: 3.6 – 11.1 TP2: 6.3 – 74.6 | * | - | - |
7 | 138 | 77 – 641 | * | - | - |
8 | 38 | - | * | - | - |
9 | 9 | 6 – 14 | * | - | - |
10 | O1: 40 O2: 118 | - | O1: 33.3 O2: 100.0 | O1: 19.3 – 123 O2: NNTB 46.8 to ∞ to NNTH 741.3 | O1: +6.7 O2: +18.0 |
11 | 7.5 | 4.8 – 14.7 | 7.1 | 4.5 – 16.9 | +0.4 |
12 | 39 | - | 38.2 | 21.7 – 158.1 | +0.8 |
13 | 4.3 | - | 4.5 | 2.6 – 17.9 | -0.2 |
14 | 5 | - | 4.9 | 3.7 – 7.1 | +0.1 |
15 | 30 | - | * | - | - |
16 | "Slightly more than 6" | - | * | - | - |
17 | NNS = 352 | - | 325.7 | 185.4 – 1337.5 | +26.3 |