Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Premenstrual symptoms
RCT	68 women, aged 25–45 years with regular periods, premenstrual distress for at least 6 months, diagnosis confirmed by prospective daily symptom rating assessment	Mean improvement in daily total Menstrual Distress Questionnaire scores from 0–2 months 0.252 with subcutaneous estradiol implant plus oral norethisterone 0.115 with placebo implant plus oral placebo	Reported as P <0.2 Further details not reported		Not significant
RCT	68 women, aged 25–45 years with regular periods, premenstrual distress for at least 6 months, diagnosis confirmed by prospective daily symptom rating assessment	Mean improvement in daily total Menstrual Distress Questionnaire scores from 0–4 months 0.206 with subcutaneous estradiol implant plus oral norethisterone 0.035 with placebo implant plus oral placebo	P <0.02	Effect size not calculated	subcutaneous estradiol implant plus oral norethisterone
RCT	68 women, aged 25–45 years with regular periods, premenstrual distress for at least 6 months, diagnosis confirmed by prospective daily symptom rating assessment	Mean improvement in daily total Menstrual Distress Questionnaire scores from 0–6 months +0.236 with subcutaneous estradiol implant plus oral norethisterone –0.030 with placebo implant plus oral placebo	P <0.01 Results were also significant at 0–8 months, and 0–10 months, but based on increasingly fewer participants (see Further information on studies)	Effect size not calculated	subcutaneous estradiol implant plus oral norethisterone
RCT	68 women, aged 25–45 years with regular periods, premenstrual distress for at least 6 months, diagnosis confirmed by prospective daily symptom rating assessment	Mean improvement in visual analogue scale score (from 0 = very well to 100 = very unwell) from 0–6 months 40.2 with subcutaneous estradiol implant plus oral norethisterone 37.6 with placebo implant plus oral placebo	P >0.1		Not significant
RCT	68 women, aged 25–45 years with regular periods, premenstrual distress for at least 6 months, diagnosis confirmed by prospective daily symptom rating assessment	Mean improvement in general health questionnaire scores (score obtained by counting number of items for which morbidity increasing) from 0–6 months 5.3 with subcutaneous estradiol implant plus oral norethisterone 5.8 with placebo implant plus oral placebo	P >0.1		Not significant