| Methods |
Random ‐ unstated in published trial. Correspondence with authors showed randomisation was done by flipping a coin for the first person and alternate assignment for other participants
No blinding
Parallel design
21 participants randomised and analysed (pain data estimated for two participants for last two recordings, 180min and next morning) |
| Participants |
Inclusion: primary dysmenorrhoea, pelvic exam in previous two years that showed no pathology
Age: 20‐38, mean 25.9 years
Location: USA |
| Interventions |
1. Low‐frequency TENS ‐ low rate 1 pulse/sec, highest intensity tolerable, pulse duration low, 40 msec
2. Placebo pill
Location: 4 points, bladder 21 and 29 (back), spleen 6 and stomach 36 (legs)
Duration: 30 min, 1 cycle |
| Outcomes |
Pain scales ‐ VAS and the pain rating index from McGill measured pre, post, 30, 60, 120, 180 min, next morning upon awakening |
| Notes |
No information on the baseline similarities of the randomised groups
Immediately after collection of baseline measurements all women received auricular acupressure, as part of another study prior to the intervention. |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Adequate sequence generation? |
High risk |
"Subjects were assigned randomly". No further details in paper. Correspondence with authors showed randomisation was done by flipping a coin for the first person and alternate assignment for other participants. |
| Allocation concealment? |
Unclear risk |
No details provided. |
| Blinding?
All outcomes |
High risk |
No blinding. |
| Incomplete outcome data addressed?
All outcomes |
Low risk |
Two participants in the experimental group did not complete posttreatment measures as they were asleep and needing to take additional medication, therefore used last value carried forward. |
| Free of selective reporting? |
Low risk |
Main outcome measures were reported. |
