Various analgesics v placebo for dysmenorrhoea*

Weighted event rates
Analgesic (number of trials)AnalgesicPlaceboRBI (95% CI)NNT (95% CI)
Outcome: pain relief
Naproxen (13)59%17%217% (172 to 265) 3 (2 to 4)
Ibuprofen (9)70%31%141% (58 to 268) 3 (2 to 4)
Mefenamic acid (3)64%31%103% (65 to 148) 3 (2 to 5)
Aspirin (5)29%18% 60% (12 to 129)10 (6 to 50)
Weighted event rates
Analgesic (number of trials)AnalgesicPlaceboRRR (95% CI)NNT (95% CI)
Outcome: use of rescue analgesics
Naproxen (10)18%51%62% (56 to 68)4 (3 to 5)
Ibuprofen (2)13%57%77% (59 to 87)3 (2 to 4)
Aspirin (3)39%70%21% (−8 to 42)Not significant
Weighted event rates
Analgesic (number of trials)AnalgesicPlaceboRRR (95% CI)NNT (95% CI)
* Abbreviations defined in glossary. Data provided by author.
Outcome: restrictions in daily life
Naproxen (7)60%86%29% (15 to 40)5 (3 to 8)
Ibuprofen (3)12%55%74% (58 to 84)3 (2 to 5)
Aspirin (3)50%62%18% (−4 to 36)Not significant