Theory-based strategies for improving contraceptive use: a systematic review

Background: Theories and models help explain how behavior change occurs. We systematically reviewed randomized controlled trials that examined theory-based interventions for improving contraceptive use. Study Design: We searched electronic databases for eligible trials. Primary outcomes included pregnancy and contraceptive use. We calculated the odds ratio for dichotomous outcomes and the mean difference for continuous data. Results: Of 14 included trials, 10 showed positive results for a theory-based group: 2 of 10 studies with pregnancy or birth data, 4 of 9 addressing contraceptive use (for contraception) and 5 of 9 with condom use (to prevent HIV/sexually transmitted infections). An experimental group had favorable results for six of seven trials based on Social Cognitive Theory, two based on other social cognition models and two using motivational interviewing. Most interventions focused on adolescents and involved multiple sessions. Conclusions: Effects were not consistent across outcomes and comparisons. The field could benefit from thorough use of single theories and better reporting on intervention implementation. (C) 2009 Elsevier Inc. All rights reserved.