Table 2:

All-cause mortality outcomes in landmark randomized controlled trials with statistically significant results

Study Treatment, no. * Control, no. Treatment duration Outcome time, yr § Death risk ARR ‡‡ p value §§ NNT-outcome time ¶¶ 1-year-death NNT (95% CI) ***
Treatment ** Control ††
Liggins and Howie 2 126 100 1 d 0.0192 0.063 0.18 0.117 0.02 8.6 0.16 (0.09 to 0.64)
Guérin et al. 3 237 229 4 d 0.0767 0.236 0.41 0.174 <0.001 5.7 0.4 (1.0 to 2.7)
Ramond et al. 4 32 29 28 d 0.4932 0.125 0.552 0.427 0.001 2.3 1.2 (0.8 to 2.3)
Rivers et al. 5 130 133 6 h 0.1644 0.385 0.526 0.142 0.03 7.1 1.2 (0.6 to 7.3)
Sort et al. 6 63 63 3 d 0.2466 0.222 0.413 0.19 0.03 5.3 1.3 (0.7 to 7.9)
Herbrecht et al. 7 144 133 12 wk 0.2308 0.292 0.414 0.122 0.02 8.2 1.9 (1.0 to 23)
de Gans and van de Beek 8 157 144 4 d 0.1538 0.07 0.146 0.076 0.04 13.2 2.0 (1.1 to 27)
Hypothermia after Cardiac Arrest Study Group 9 137 138 1 d 0.5 0.409 0.551 0.142 0.02 7 3.5 (1.9 to 20)
García-Pagán et al. 10 32 31 1.3333 0.125 0.387 0.262 0.01 3.8 5.1 (2.1 to 18)
Williams-Johnson et al. 11 10 060 10 067 8 h 0.0769 0.145 0.16 0.015 0.0035 67.6 5.2 (3.1 to 16)
CONSENSUS Trial Study Group 12 127 126 0.9863 0.362 0.524 0.162 0.003 6.2 6.1 (3.5 to 24)
Finfer et al. 13 3010 3012 4.2 d 0.2466 0.275 0.249 −0.026 0.02 −38.3 −9.5 (−64 to −5.1)
Rose et al. 14 61 61 2.1667 0.672 0.885 0.213 <0.001 4.7 10 (2.8 to 14)
Malmberg et al. 15 306 314 ≥ 3 min 1 0.186 0.261 0.075 0.027 13.4 13 (7.1 to 104)
Chen et al. 16 22 961 22 891 15 d 0.0767 0.075 0.081 0.005 0.03 184.2 14 (7.4 to 147)
Pitt et al. 17 822 841 2 0.345 0.459 0.113 0.001 8.8 18 (12 to 30)
MERIT-HF Study Group 19 1990 2001 1 0.073 0.108 0.036 <0.001 28.1 28 (19 to 56)
Moss et al. 20 742 490 1.6667 0.142 0.198 0.056 0.016 17.7 30 (17 to 127)
Chimowitz et al. 21 289 280 1.85 0.097 0.043 −0.054 0.02 −18.5 −34 (−148 to −19)
Bardy et al. 22 829 847 3.7917 0.22 0.288 0.069 0.007 14.6 55 (45 to 185)
Yusuf et al. 23 1,285 1,284 3.45 0.352 0.397 0.045 0.0036 22 76 (42 to 428)
β-Blocker Heart Attack Trial 24 1916 1921 2.0833 0.072 0.098 0.026 <0.005 38.7 81 (69 to 365)
Pfeffer et al. 25 1115 1116 3.5 0.204 0.246 0.042 0.019 23.8 83 (46 to 480)
Wallentin et al. 26 9333 9291 1 0.043 0.054 0.012 <0.001 85.4 85 (56 to 181)
Farkouh et al. 27 947 953 5 0.088 0.12 0.032 0.049 31.3 156 (84 to 1084)
Yusuf et al. 29 4645 4652 3.5 0.104 0.122 0.019 0.005 53.9 270 (159 to 881)
Gerstein et al. 30 5128 5123 1.9 0.05 0.04 −0.01 0.04 −95.3 −334 (∞ to −54)
Ridker et al. 31 8901 8901 7.6 0.022 0.028 0.006 0.02 181.7 345 (99 to ∞)
Davies et al. 32 6454 6440 5 yr 7.6 0.214 0.227 0.014 0.04 73.2 556 (272 to ∞)
  • Note: ARR = absolute risk reduction, CI = confidence interval, NNT = number needed to treat, – = 1 procedure or surgery, ∞ = ongoing treatment throughout observation.

  • * Number of people randomly assigned to intervention group.

  • Number of people randomly assigned to control group.

  • Duration of active treatment for the intervention group.

  • § Outcome time is the time from randomization at which death count or risk was measured. In closed studies, it equals the time patients received active treatment plus subsequent observation time required to achieve observed death risk.

  • In open studies (i.e., outcome time varies between patients in study), the average follow-up time was used.

  • Neonatal (not maternal) death risk.

  • ** Proportion dead in intervention group (no. dead ÷ no. randomly assigned).

  • †† Proportion dead in control group (no. dead ÷ no. randomly assigned).

  • ‡‡ Absolute risk reduction for death, calculated as death risk for control group – death risk for intervention group.

  • §§ Two-sided p value for comparison of death risk in groups.

  • ¶¶ Number needed to treat to prevent 1 death by outcome time.

  • *** Number needed to treat to prevent 1 death by 1 year. If negative, this is the number needed to treat to cause 1 death by 1 year (the 1-year-death number needed to harm).