You will be provided with the titles and abstracts of a collection of medical RCT reports studying a clinical question -- for instance, the efficacy of an intervention on some medical outcome. Please write a few sentences synthesizing the findings of these reports, which could serve as a conclusion section for a systematic review article. Your response should not include any other text. The RCT reports are below.



Title 1:
Extended regimens of the contraceptive vaginal ring: a randomized trial.
Abstract 1:
To compare the bleeding patterns and tolerability of 3 different extended ring regimens with those of the standard 28-day cycle with 21 days of contraceptive vaginal ring use followed by 7 ring-free days.
                Following a run-in 28-day ring cycle, women were randomized to 1 of 4 regimens: monthly (28-day cycle), every other month (49-day cycle), every third month (91-day cycle), or continuous (364-day cycle). Treatment duration was 1 year. Daily bleeding diary, interval visit questionnaire, and examination data were collected.
                A total of 561 women were enrolled, 429 were subsequently randomized, and 289 (67.4%) women completed the entire year. All schedules were well tolerated and acceptable to women, but study completion rates were higher for the shorter cycles. Bleeding days were reduced with postponement of the withdrawal bleeding (ring-free) week, but spotting days increased. For example, women using the continuous or 364-day ring cycle reported a median of zero bleeding days but 10-12 days of spotting during the first 3 months of extended use. Unscheduled bleeding during ring use was the lowest with the traditional 28-day cycle. Adverse events, blood pressure, body weight, and laboratory findings were comparable over the 4 treatment groups.
                The combination vaginal contraceptive ring can be used for extended cycles to alter the bleeding schedule. Women willing to tolerate some spotting might choose the longer extensions to have fewer menstrual periods.
                I.


Title 2:
Menstrual reduction with extended use of combination oral contraceptive pills: randomized controlled trial.
Abstract 2:
To compare a traditional 28-day cycle to an extended 49-day cycle of the 30 microg ethinyl estradiol (E2)/300 microg norgestrel monophasic birth control pill regimen.
                Ninety subjects randomized to either 28-day cycles with 21 active pills or 49-day cycles with 42 active pills for a prospective open label trial over four 84-day reference periods or trimesters. Bleeding, pill taking, and symptom diaries were completed. The sample size with 80% power to detect a 40% reduction in bleeding days required 24 subjects in each arm.
                Of the 90 women, 24 subjects (54.5%) on the 28-day cycle and 29 (63%) on the 49-day cycle completed the entire study (P =.41). There were no statistically significant differences between the two groups in demographics or continuation rates. There was a significant reduction in bleeding days in the experimental arm beginning in the first trimester (28-day = 10.9, 49-day = 6.4 mean days of bleeding, P <.001) and continuing to the fourth trimester (28-day = 11.3, 49-day = 5.8 mean days, P =.005). The number of spotting days was similar between both schedules in the first trimester (28-day = 4.8, 49-day = 3.7 mean days, P =.24) and continued into the fourth trimester (28-day = 3.4, 49-day = 2.9 mean days, P =.30). Annual expenditure for hygiene products was significantly less for extended use subjects (28-day = $41.45, 49-day = $17.54 spent, P <.001).
                Extension of the 28-day oral contraceptive (OC) cycle to a 49-day cycle resulted in fewer bleeding days and no increase in mean spotting days or bleeding episodes.


Title 3:
Long-interval treatment regimen with a desogestrel-containing oral contraceptive.
Abstract 3:
A randomized multicenter study was performed in order to investigate the acceptance of a low-dose OC (30 micrograms of ethinyloestradiol and 150 micrograms of desogestrel), using a 9 weeks on and 1 week off schedule (prolonged regimen, n = 198), compared to a traditional 3 weeks on, 1 week off schedule (standard regimen, n = 96). Haemoglobin and blood pressure remained the same in both groups during the study. No significant differences were found in body weight changes between the two groups. There was significantly more breakthrough bleeding and spotting in the group with prolonged regimen than in the group with standard regimen, but both breakthrough bleeding and spotting decreased during the trial. Irregular bleeding was significantly less in women who were already using OC, compared to "new starters." No serious side effects occurred. Significantly more women stopped the trial because of bleeding problems in the group with prolonged regimen, while there were significantly more women who stopped the trial because of headache in the group with standard regimen. After completing 12 months, or after premature withdrawal from the study, each women completed a questionnaire. Sixty-three per cent of the women preferred the studied alternative and twenty-six per cent preferred the traditional OC.


Title 4:
Continuous combination oral contraceptive pills to eliminate withdrawal bleeding: a randomized trial.
Abstract 4:
To compare bleeding profiles of a traditional 28-day oral contraceptive pill cycle with continuous administration.
                After a 28-day run-in cycle, women were randomized to either 28-day cycles (21 active pills and a pill-free week) or continuous use of the same 20 microg ethinyl estradiol/100 microg levonorgestrel formulation for 12 study cycles (336 days). The number of bleeding and spotting days were measured by daily diary. A subset underwent cycle 1 (n = 16), and nine (n = 14) pelvic ultrasound and endometrial histology sampling. Blood pressure, weight, hemoglobin, and adverse events were measured at revisit. The sample size with 80% power to detect a 67% reduction in bleeding days required 27 subjects in each arm.
                Of the 79 subjects randomized, 28 (70%) of the 28-day cycle and 32 (82%) of the continuous-use subjects completed the entire study (P =.6). With continuous use, 49%, 68%, and 88% of women reported no bleeding during cycles 2, 6, and 12, respectively. Amenorrhea or infrequent bleeding was present in 68% of continuous users during cycles 1-3 and increased to 88% during cycles 10-12. Spotting during cycle days 1-21 increased initially with continuous use but reduced over time, and by 9 months was less than the spotting reported by cyclic users. Adverse events, blood pressure, weight, and hemoglobin findings were similar between groups.
                Extension of the 28-day oral contraceptive cycle to continuous use with a low-estrogen dose combination oral birth control pill resulted in significantly fewer bleeding days.


Title 5:
Bleeding patterns and patient acceptability of standard or continuous dosing regimens of a low-dose oral contraceptive: a randomized trial.
Abstract 5:
The purpose of this study is to compare bleeding patterns and acceptability of a contraceptive regimen of combined 20 microg ethinyl estradiol/100 microg levonorgestrel taken with and without a hormone-free interval. Thirty-two women desiring oral contraception were randomized to six 28-day cycles (standard group) or 168 days without a pill-free interval (continuous group). Participants kept a daily bleeding calendar documenting bleeding events (none, spotting or required sanitary protection) and side effects (headache, nausea, breast tenderness, depression, premenstrual syndrome and bloating). Primary outcome was number of bleeding days. Secondary outcomes included bleeding days requiring sanitary protection, amenorrhea, patient acceptability of bleeding patterns, method satisfaction and affective side effects. There were no differences in the baseline characteristics of the two groups. Although total bleeding days were fewer in the continuous group (mean = 25.9 vs. 34.9 days), this result did not reach statistical significance. However, women in the continuous group reported significantly fewer bleeding days that required protection (18.4 vs. 33.8 days, p < 0.01), and were more likely to have amenorrhea. Although both groups reported a high level of satisfaction with bleeding patterns and side effect profiles, women in the continuous group reported significantly fewer days of bloating (0.7 vs. 11.1 days, p = 0.04), and menstrual pain (1.9 vs. 13.3 days, p < 0.01). Continuous use of 20 microg ethinyl estradiol/100 microg levonorgestrel is associated with less bleeding requiring protection, and more amenorrhea than standard administration. Taken with or without a hormone-free interval, this oral contraceptive formulation is highly acceptable with regard to bleeding patterns and side effect profile. The continuous group had fewer light and moderate bleeding days, less bloating and menstrual pain. For patients who are seeking these results, this method may be more desirable.


Title 6:
A multicenter, randomized study of an extended cycle oral contraceptive.
Abstract 6:
To assess the efficacy and safety of Seasonale, 91-day extended cycle oral contraceptive (OC).
                A parallel, randomized, multicenter open-label, 1-year study of the OC Seasonale [30 microg ethinyl estradiol (EE)/150 microg levonorgestrel (LNG), and Nordette-28 (30 microg EE/150 microg LNG)] in sexually active, adult women (18-40 years) of childbearing potential. Patients received either four 91-day cycles of extended cycle regimen OC, or 13 cycles of the conventional 28-day OC with daily monitoring of compliance and bleeding via electronic diaries.
                When taken daily for 84 days followed by 7 days of placebo, the extended cycle regimen was effective in preventing pregnancy and had a safety profile that was comparable to that observed with the 28-day OC regimen that served as the control. While unscheduled (breakthrough) bleeding was reported among patients treated with the extended cycle regimen, it decreased with each successive cycle of therapy and was comparable to that reported by patients who received the conventional OC regimen by the fourth extended cycle.
                This study demonstrated that Seasonale, 91-day extended cycle OC containing 84 days of 30 microg EE/150 microg LNG followed by 7 days of placebo, was effective, safe and well tolerated.


Title 7:
Comparative study on intermittent versus continuous use of a contraceptive pill administered by vaginal route.
Abstract 7:
A multicenter, international, randomized, comparative trial was conducted to assess the acceptability, efficacy and safety of two different schedules of a contraceptive pill, containing 250 micrograms levonorgestrel and 50 micrograms ethinyl estradiol, administered by the vaginal route. One schedule of daily administration for 21 days with a seven-day interruption to allow withdrawal bleeding was compared to daily administration without interruption for bleeding. A total of 900 women were recruited in three countries, Brazil, Egypt and China; 7,090 women-months of vaginal pill use were recorded (3,364 using the pills intermittently and 3,726 continuously). Four undesired pregnancies occurred, one in Egypt and three in China, all four in women using the pills intermittently. There was a statistically significant difference (p = 0.486) in pregnancy rate between the two groups. There were no other significant differences in discontinuation rates despite marked differences in bleeding patterns, amenorrhea predominating in the continuous use group. Hemoglobin levels increased significantly in the two groups but hematocrit was significantly higher in the continuous use group.


Title 8:
Extended use of transdermal norelgestromin/ethinyl estradiol: a randomized trial.
Abstract 8:
To compare bleeding profiles and satisfaction among women using a norelgestromin/ethinyl estradiol (E2) transdermal contraceptive patch in an extended regimen to those among women using a traditional 28-day patch regimen.
                Healthy, regularly menstruating women (N = 239) were randomly assigned (2:1 ratio) to receive the norelgestromin/ethinyl E2 transdermal patch in an extended regimen (weekly application for 12 consecutive weeks, 1 patch-free week, and 3 more consecutive weekly applications, n = 158) or a cyclic regimen (4 consecutive cycles of 3 weekly applications and 1 patch-free week, n = 81). Subjects recorded bleeding data daily and completed satisfaction questionnaires. Subjects and investigators provided overall assessments of the regimens.
                Extended use of the norelgestromin/ethinyl E2 transdermal patch resulted in fewer median bleeding days (6 compared with 14, P < .001), bleeding episodes (1 compared with 3, P < .001), and bleeding or spotting episodes (2 compared with 3, P < .001) compared with cyclic use during days 1-84; median numbers of bleeding or spotting days were similar between regimens (14 compared with 16, P = .407) during this time. Extended use delayed median time to first bleeding to 54 days compared with 25 days with cyclic (P < .001). Subjects were highly satisfied with both regimens. Although not statistically significant, slightly more adverse events were reported with the extended than with the 28-day regimen.
                Compared with cyclic use, extended use of the norelgestromin/ethinyl E2 transdermal patch delayed menses and resulted in fewer bleeding days. This regimen may represent a useful alternative for women who prefer fewer episodes of withdrawal bleeding.
Evidence from existing randomized control trials comparing CHCs given continuously (greater than 28 days of active combined hormones) to traditional monthly cyclic dosing (21 days of active hormone and 7 days of placebo) is of good quality. However, the variations in type of hormones and time length for continuous dosing make a formal meta-analysis impossible. Future studies should choose a previously described type of CHC and dosing regimen. More attention needs to be directed towards participant satisfaction and menstruation-associated symptoms.