| Methods |
Randomisation was done statistically by the pharmaceutical company, allocation concealment was via a secure code not broken until after all data was collected.
Double blind
322 women initially randomised, 23 drop outs (5 pregnancies, 6 disappeared, 4 somatic complaints such as bleeding skin troubles or nausea, 3 interfering illness, 4 change of mind).
213 of the initial group randomised had dysmenorrhoea, with 203 women with dysmenorrhoea analysed. |
| Participants |
Inclusion: women aged between 18 to 45, absence of actual known disease, normal menstrual cycle, no actual or planned pregnancy.
Exclusion: use of oral contraceptive in last 3 months
Age: 27.5 (7.7)
Source: female personnel from the general post office, the general telephone company, 4 nursing schools, 2 hospitals, the psychological institute at the local university
Location: Stockholm, Sweden. |
| Interventions |
1. norgestrel 1mg, ethinyl oestradiol 0.05mg
2. norgestrel 0.5mg, ethinyl oestradiol 0.05mg (Ovral)
3. norgestrel 0.06mg, ethinyl oestradiol 0.05mg
4. placebo
Treatment was for 2 months and 1 tablet free month follow up. |
| Outcomes |
Dysmenorrhoea (improved, worse, unchanged, none prior to treatment) |
| Notes |
|
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Adequate sequence generation? |
Unclear risk |
Pharmaceutical company provided the sequence |
| Allocation concealment? |
Low risk |
A ‐ Adequate, via a secure code not broken until after all data was collected. |
| Blinding?
All outcomes |
Low risk |
Double |
| Incomplete outcome data addressed?
All outcomes |
High risk |
|
| Free of selective reporting? |
Unclear risk |
No data provided |
| Power calculations |
High risk |
|
| Dropouts reported |
High risk |
|
| Baseline comparability |
Low risk |
|
