title: Theory-based strategies for improving contraceptive use: a systematic review.
abstract: 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.
  
  
  METHODS
  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.
authors.affiliation: Family Health International, Research Triangle Park, NC 27709, USA. llopez@fhi.org
authors.forename: Laureen M
authors.initials: LM
authors.lastname: Lopez
authors.forename: Elizabeth E
authors.initials: EE
authors.lastname: Tolley
authors.forename: David A
authors.initials: DA
authors.lastname: Grimes
authors.forename: Mario
authors.initials: M
authors.lastname: Chen-Mok
mesh_terms: D003267:Contraception / Q000523:psychology*; D003268:Contraception Behavior / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D008960:Models, Psychological; D011247:Pregnancy; D016032:Randomized Controlled Trials as Topic