Randomized trial of the effect of tailored versus standard use of the combined oral contraceptive pill on continuation rates at 1 year.

BACKGROUND: There is growing interest from women and clinicians in extended or tailored use of the combined oral contraceptive (COC) pill. Potential advantages include less bleeding, greater contraceptive efficacy and user satisfaction. We examined the effect of a tailored pill regimen, compared with the standard regimen, on continuation and satisfaction rates at 1 year and associated bleeding patterns. STUDY DESIGN: This was a randomized controlled trial with 503 women aged 18-45 years. Women were randomized to either the standard regimen (21 daily pills followed by a 7-day pill-free interval) or tailored regimen (daily pills until three consecutive days bleeding triggers a 3-day pill-free interval) of Microgynon 30® (ethinyl oestradiol 30 mcg, levonorgestrel 150 mcg). Primary outcome was COC continuation at 12 months; secondary outcomes included satisfaction with pill regimen regarding contraception and bleeding pattern. Daily electronic diaries were used to record women's pill use, switching to other contraceptive methods, menstrual bleeding patterns and satisfaction levels. RESULTS: Eighty-three percent of women were already taking the COC at recruitment, 13% were restarting the COC and 4% were first time COC users. Seventy-one percent of all women were followed up at 12 months. Continuation rates at 1 year were 82% in the tailored arm versus 80% in the standard arm [odds ratio (OR)=1.13; 95% confidence interval (CI)=0.67-1.91]. Satisfaction with contraceptive regimen was 86% (tailored) versus 94% (standard) (OR=0.37; 95% CI=0.17-0.79), and satisfaction with bleeding pattern was 79% versus 87%, respectively (OR=0.53; 95% CI=0.30-0.93). Median number of bleeding days per month was 2.4 (tailored) and 4.9 (standard). Incidence, duration and intensity of bleeding episodes were significantly lower in the tailored arm. CONCLUSIONS: In women familiar with standard use of the COC, switching to tailored COC use or continuing with standard use were both associated with high COC continuation rates and high satisfaction with contraceptive regimen and bleeding pattern. While significant differences tended to favor the standard group, tailored COC use was associated with significantly less bleeding, suited some women very well and can provide a suitable alternative to standard use.