Probability of Continuation: With Triphasic and Monophasic (LD).

Introduction: Despite the same complications for LD and triphasic pills, it seems as if the continuation times for the two birth control methods are different. Aims: To compare the continuation times and side effects of triphasic and monophasic LD use, and identify factors related to continuation and discontinuation. Methods and Materials: A historical cohort study was conducted in Isfahan, Iran to deter-mine and compare the probability of 5 years continuation of low dose monophasic (223) and triphasic (163) use among 386 reproductive married women. Statistical analysis used: The continuation time of triphasic pill and LD pills were compared with Kaplan Meier by SPSS11.5 software. Results: The cumulative proportion of continuation was significantly different between triphasic and LD groups in the first year of use [0.98 (LD) VS 0.84 (tri phsic)]. It was found that age, number of living children, education level and employment status didn’t have any role in choosing contraceptive method (p > 0.05). In each group there was a significant rela-tionship between these variables and median duration of OCP use. Despite similar complica-tions and total discontinuation, 5 year continuation time of triphasic was lower than that observed for LD. Conclusions: It seems as though consumption of triphasic OCP requires more attention, as it should be taken on a regular schedule, and missing a dose for more than two hours reduces its efficacy. Therefore, health care professions should consid