de Mello 2004.

Methods	Allocation concealment: unclear Method of randomisation: unclear Double‐blinded parallel design 337 patients randomised and 337 analysed
Participants	Included: women with primary dysmenorrhoea for previous 3 cycles, aged 18 to 10 Excluded: use of oral contraceptives or intrauterine contraception within previous 3 months, secondary dysmenorrhoea, concomitant use of analgesics, other medical conditions (listed in study) Age: mean 28 (range 17 to 40) years Location: Mexico and Brazil
Interventions	Meloxicam 7.5 or 15 mg Mefenamic acid 500 mg Medicate 3 times daily over 3 to 5 days 3 cycles
Outcomes	Ratings for pain and tolerability
Notes	—
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Method not described
Allocation concealment (selection bias)	Unclear risk	Method not described
Blinding (performance bias and detection bias) All outcomes	Low risk	Double‐blinded, "matching" placebo
Selective reporting (reporting bias)	High risk	Adverse effects data not solicited prospectively, "no primary endpoints with regard to safety were defined"
Complete follow‐up?	Low risk	337/337 in safety analyses
Potential bias related to study funding	Unclear risk	Boehringer‐Ingelheim sponsored and conducted