A Cochrane review «Brown J, Crawford TJ, Datta S et al. Oral contrace...»1 «Oral contraceptives for pain associated with endometriosis»1 included 5 trials, of which 3 trials including a total of 404 subjects provided data for analysis. Compared with placebo, combined oral contraceptives (COC) improved self-reported pain: in dysmenorrhoea verbal rating scale (scale 0 to 3) mean difference (MD) -1.30 points, 95% CI -1.84 to -0.76; 1 RCT, n=96; in dysmenorrhoea visual analogue scale MD -23.68 points, 95% CI -28.75 to -18.62; 2 RCTs, n= 327, and a reduction in menstrual pain from baseline to the end of treatment (MD 2.10 points, 95% CI 1.38 to 2.82; 1 RCT, n=169). One underpowered unblinded trial compared COC with goserelin. At the end of treatment, the women in the goserelin group were amenorrhoeic. At 6 months' follow-up, there was no clear difference between the groups.
A systematic review «Jensen JT, Schlaff W, Gordon K. Use of combined ho...»2 included 9 RCTs. The combined hormonal contraceptives (CHC) significantly reduced dysmenorrhea, pelvic pain, and dyspareunia compared with placebo, comparator or no treatment from baseline in most studies; continuous administration seemed to be more useful than cyclic administration. The effectiveness of CHC for pain reduction was similar to or less than that of oral progestins and GnRH agonists.
A systematic review «Grandi G, Barra F, Ferrero S, et al. Hormonal cont...»3 assessed the effectiveness of hormonal contraception on endometriosis-related pain (dysmenorrhoea, pelvic pain and dyspareunia), quality of life (QoL) and postoperative rate of disease recurrence compared with placebo or comparator therapies. CHC and progestin-only contraceptive (POC) treatments were associated with clinically significant reductions in dysmenorrhoea, often accompanied by reductions in non-cyclical pelvic pain and dyspareunia and an improvement in QoL. Only 3 studies found that the postoperative use of COCs (ethinylestradiol [EE]/norethisterone acetate, EE/desogestrel and EE/gestodene) reduced the risk of disease recurrence. There was no evidence that POC reduced the risk of disease recurrence.
An RCT «Grandi G, Barra F, Ferrero S, et al. Hormonal cont...»3 evaluated the clinical and cost-effectiveness of 150 mg depot medroxyprogesterone acetate or 52 mg LNG-IUS compared with the combined oral contraceptive pill (COC, 30 µg EE with 150 µg levonorgestrel) in preventing recurrence (n=405). In 3 years follow-up, pain scores improved in both groups (24 and 23 points on average) compared with preoperative values, there was no difference between the groups. The long-acting reversible contraceptive group underwent fewer surgical procedures or second-line treatments compared with the COC group (73 vs. 97; hazard ratio 0.67, 95% CI 0.44 to 1.00).
Comment: The quality of evidence is downgraded by study limitations (unclear allocation concealment and blinding).