| Study characteristics |
| Methods |
Randomised controlled trial |
| Participants |
Women aged 16 to 30 years with primary dysmenorrhoea (n = 40) |
| Interventions |
Nifedipine 10 mg sublingual 8 hourly as needed versus placebo |
| Outcomes |
Improvement in pain, duration of menstruation, amount of bleeding, menstrual symptoms/side‐effects |
| Notes |
|
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
Low risk |
Used random number table with double‐blind technique |
| Allocation concealment (selection bias) |
Unclear risk |
Not described |
| Blinding of participants and personnel (performance bias)
All outcomes |
Low risk |
Stated used double‐blind technique |
| Blinding of outcome assessment (detection bias)
All outcomes |
Low risk |
Stated used double‐blind technique |
| Incomplete outcome data (attrition bias)
All outcomes |
Unclear risk |
Unclear if all participants accounted for |
| Selective reporting (reporting bias) |
Low risk |
Questionnaire used for all participants to collect data |
| Other bias |
Low risk |
Nil identified |
