RESUMO
A prospective study was conducted with 430 new depot medroxyprogesterone acetate (DMPA) acceptors to estimate continuation rates and investigate factors associated with length of use. Data were collected on services received and sociodemographic characteristics of participants. Women were enrolled over the course of 1 year and were followed for up to 13 months. Failure to return to the same clinic within 104 days of the last injection was the outcome of interest. The 3-, 6-, 9-, and 12-month continuation rates were 68%, 67%, 55%, and 51%, respectively. In the bivariate analysis, women who were told to return to the clinic for side effects were more likely to continue using DMPA than those who were not given such advice (p <0.05). Likewise, women who received information on DMPA efficacy, side effects, and amenorrhea were more likely to continue using DMPA compared to those who did not receive such information (p <0.05). A proportional hazards regression model was constructed to estimate the simultaneous effect of various factors on length of use. In results consistent with the bivariate analysis, women who were told to return to the clinic were 2.7 times more likely to continue using DMPA compared to women who did not receive that advice. Likewise, women who were told about the possibility of amenorrhea were 2.5 times more likely to continue using DMPA compared to those who did not receive that information. The regression model also identified new factors such as number of children, attitude toward menstruation, lactating at admission, and spousal input on method choice. The findings suggest that providers play an important role in ensuring the highest possible continuation rates for DMPA.