Smith 1995.

Methods	Randomized active controlled parallel trial
Participants	Women diagnosed with PMS and who showed a statistically significant PMS trend in 3 or more symptoms on a daily symptoms rating scale (PDQ) kept prospectively for a 4 to 8 week period of time
Interventions	100 µg versus 200 µg transdermal oestradiol patches 56 women were allocated to treatment with estraderm TTS 100 µg twice weekly continuously (El00 group), 56 women to treatment with Estraderm TTS 200 µg twice weekly continuously (E200 group). In both the El00 and E200 groups half of the women were allocated to take dydrogesterone 10 mg daily from day 17 to 26 of the cycle and half to take medroxyprogesterone acetate 5 mg daily from day 17 to 26 Duration: follow‐up visits were scheduled at the end of the 4th and 8th months of treatment.
Outcomes	Symptom score VAS for pain score Drop‐outs Adverse effects (e.g. skin irritation, menstruation problems, bloating) Participants' satisfaction Serum oestradiol levels
Notes	Trial conducted in the UK, funding source unknown.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No details provided on implementation of envelope method
Allocation concealment (selection bias)	Low risk	Opaque sealed envelope
Blinding of participants and personnel (performance bias) All outcomes	High risk	Non‐blinded trial
Blinding of outcome assessment (detection bias) All outcomes	High risk	Non‐blinded trial
Incomplete outcome data (attrition bias) All outcomes	High risk	21% dropout and 8% lost to follow‐up
Selective reporting (reporting bias)	Low risk	All expected outcomes were reported
Other bias	Low risk	No specific reasons to suspect other bias