Comparison of continuation rates for hormonal contraception among adolescents

Abstract

Background: Inadequate contraception is common among sexually active female adolescents, resulting in a high incidence of unwanted pregnancy. The authors were interested in comparing continuation rates for the different forms of hormonal contraception in this age group.

Methods: A retrospective chart review. The setting was an urban clinic in a large Midwestern city. Participants were 64% black, 34% white, and the average age was 15.5 years (+/- 1.6 SD), with implant users significantly older than oral contraceptive pill (OCP) users (P < .05). Interventions were self-selection to depo-medroxyprogesterone acetate (Depo-Provera; DMPA), levonorgestrel implants (Norplant), or oral contraceptive pills (OCPs). Previous pregnancy was significantly more prevalent in implant and DMPA users than in OCP users (P < .001). Over 4 years of follow-up, continuation rates were significantly higher for implant users than for the other hormonal groups (P < .001). At 1 year, continuation rates were as follows: 82% implants, 45% DMPA, and 12% OCPs. Combining these rates with those of the subsample who switched without interruption to another hormonal method, "continued protection" rates were much higher after 1 year: 96% implants, 83% DMPA, and 49% OCPs. Calculations of contraceptive "restarts," i.e., hormonal method use in those who discontinued and then restarted after a gap of time, also increased to the prevalence of contraceptive protection.

Conclusion: Continuation rates for levonorgestrel implants were significantly higher than those for DMPA and OCPs, the latter group having the lowest continuation rates. Factoring in switches and restarts to other hormonal methods further boosted the prevalence rates of contraceptive use in the adolescent population.