Coronary heart disease (CHD) event prevention for statins v placebo*
| Individual trials (combined trials)† | Patient group | Mean or median follow up | RRR (95% CI) | NNT (CI) | NNT/year (CI) |
|---|---|---|---|---|---|
| *AFCAPS/TexCAPS = AirForce/Texas Coronary Atherosclerosis Prevention Study; WOSCOPS = West of Scotland Coronary Prevention Study; CARE = Cholesterol and Recurrent Events; LIPID = Long-term Intervention with Pravastatin in Ischaemic Disease trial; 4S = Scandinavian Simvastatin Survival Study. Abbreviations defined in glossary. Data adapted from Kumana et al,1 which contains references for these trials. The combined NNT/year for secondary prevention trials was lower than that for primary prevention and for individual trials only that for 4S was lower than the others (p<0.05). | |||||
| †Results are weighted for combined trials. | |||||
| a) AFCAPS/TexCAPS | No CHD, normal cholesterol | 5.4 years | 37% (21 to 50) | 49 (33 to 99) | 256 (170 to 514) |
| b) WOSCOPS | No CHD, high cholesterol | 4.9 years | 31% (17 to 43) | 44 (29 to 95) | 217 (141 to 463) |
| c) CARE | CHD, normal cholesterol | 5.0 years | 24% (9 to 36) | 33 (20 to 99) | 167 (100 to 496) |
| d) LIPID | CHD, normal cholesterol | 6.1 years | 24% (12 to 35) | 28 (20 to 48) | 172 (122 to 294) |
| e) 4S | CHD, high cholesterol | 5.2 years | 34% (25 to 41) | 12 (9 to 17) | 63 (49 to 89) |
| (a + b) | No CHD | 5.2 years | 33% (22 to 42) | 47 (34 to 74) | 237 (177 to 382) |
| (c + d + e) | CHD | 5.4 years | 26% (20 to 31) | 23 (19 to 31) | 129 (103 to 172) |
| (a + c + d) | Normal cholesterol | 5.5 years | 25% (18 to 31) | 39 (30 to 55) | 209 (163 to 398) |
| (b + e) | High cholesterol | 5.2 years | 30% (23 to 37) | 29 (22 to 43) | 151 (114 to 221) |