IntroductionExisting estimates of contraceptive use in Tanzania rely on cross-sectional or retrospective study designs. This study used a 2-year, retrospective, month-by-month calendar of contraceptive utilization among women aged 15–49 years.MethodsWe estimated the median duration of contraceptive use, factors associated with use, and contraceptive discontinuation rates in sexually active women, using life tables and Cox proportional hazard model.ResultsA total of 5416 women contributed to the analysis in the study. Of the 5416 women, 942 (17%) had never had sex, 410 (7.6%) had no sexual partner in the last year. Among the 5416 women, 4064 were sexually active during the period, 814 (21.1%) were pregnant or amenorrheic, 610 (15.0%) were using contraception, and 1203 (29.6%) did not want to get pregnant but were not using contraception. In the 1813 women who wanted to avoid pregnancy, contraceptive use was lower among women over 35 years compared to younger ones (OR = 0.28, 95%CI: 0.19, 0.41), and in HIV positive women (OR = 0.89, 95%CI: 0.60–1.32). On the other hand, use was higher among women who were married/living together compared to unmarried ones (OR = 2.23, 95% CI: 1.54, 3.23). Using a 2-year retrospective contraceptive calendar, 1054 women reported contraceptive use, 15.8% discontinued within 6 months and 30.5% discontinued within 12 months. Higher rates of contraceptive discontinuation were observed among women who used pills (OR = 1.86, 95%CI: 1.25, 2.77) or injections (OR = 2.04, 95%CI: 1.59, 2.61) compared to those who used implants.ConclusionContraceptive use was significantly associated with age, education and parity, but not with HIV status. HIV status, number of living children and education are not statistically associated with discontinuation of contraceptive use Pills and injections had the highest rates of discontinuation. Wider choice and greater accessibility of long-acting contraceptive methods with better effectiveness and convenience may serve women better. Furthermore, special efforts may be needed to remove barriers to contraceptive use amongst younger women.

Male circumcision has a protective effect against HIV infection in this population, which may be stronger in urban areas and roadside settlements than in the rural areas. Ethnic group and religious denomination are no longer the sole determinants of male circumcision.