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

Despite the same complications for LD and triphasic pills, it seems as if the continuation times for the two birth control methods are different. 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 determine 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. 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 relationship between these variables and median duration of OCP use. Despite similar complications and total discontinuation, 5 year continuation time of triphasic was lower than that observed for LD. 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 consider more factors before offering clients triphasic pills in order to reduce discontinuation time.