Observed 15-year ARRs and numbers needed to treat/harm for aspirin
| Total study population | Women <65 years | Women ≥65 years | ||||
|---|---|---|---|---|---|---|
| ARR (95% CI) | NNT* or NNH† (95% CI) | ARR (95% CI) | NNT* or NNH† (95% CI) | ARR (95% CI) | NNT* or NNH† (95% CI) | |
| Major cardiovascular event | 0.27 (0.06 to 0.86) | 371 (116 to >1000)* | −0.06 (−0.39 to 0.26) | >1000† (259† to 382*) | 3.11 (1.67 to 5.27) | 32 (19 to 60)* |
| Colorectal cancer | 0.14 (0.02 to 0.59) | 709 (170 to >1000)* | 0.17 (0.04 to 0.55) | 581 (181 to >1000)* | −0.11 (−1.15 to 0.93) | 924† (87† to 107*) |
| Non-colorectal cancer | −0.08 (−0.80 to 0.64) | >1000† (124† to 156*) | −0.32 (−1.06 to 0.42) | 312† (94† to 237*) | 2.05 (0.43 to 6.28) | 49 (16 to 235)* |
| Major gastrointestinal bleeding | −0.75 (−0.50 to −1.00) | 133 (100 to 198)† | −0.64 (−0.40 to −0.87) | 157 (114 to 251)† | −1.66 (−0.50 to −2.82) | 60 (35 to 199)† |
| Total | −0.42 (−1.29 to 0.45) | 238† (78† to 223*) | −0.85 (−1.72 to 0.03) | 118† (58† to >1000*) | 3.39 (0.98 to 8.42) | 29 (12 to 102)* |
| Total, adjusted weight of 0.5 for gastrointestinal bleeding | −0.05 (−0.92 to 0.82) | >1000† (109† to 121*) | −0.53 (−1.40 to 0.34) | 189† (71† to 291*) | 4.22 (1.59 to 8.90) | 24 (11 to 63)* |
| Total, adjusted weight of 0.25 for gastrointestinal bleeding | 0.14 (0.00 to 7.59) | 703 (13 to >1000)* | −0.37 (−1.24 to 0.50) | 271† (81† to 199*) | 4.64 (1.92 to 9.19) | 22 (11 to 52)* |
| Total, adjusted weight of 0.1 for gastrointestinal bleeding | 0.25 (0.00 to 3.43) | 393 (29 to >1000)* | −0.27 (−1.15 to 0.60) | 365† (87† to 167*) | 4.89 (2.13 to 9.38) | 20 (11 to 47)* |
Risks were estimated based on the cumulative incidence function, accounting for competing risk.
*NNT, number needed to treat.
†NNH, number needed to harm.
ARR, absolute risk reduction (in %).