Theory-based interventions for contraception.
BACKGROUND
The explicit use of theory in research helps expand the knowledge base. Theories and models have been used extensively in HIV-prevention research and in interventions for preventing sexually transmitted infections (STIs). The health behavior field uses many theories or models of change. However, educational interventions addressing contraception often have no stated theoretical base.


OBJECTIVE
Review randomized controlled trials that tested a theoretical approach to inform contraceptive choice; encourage contraceptive use; or promote adherence to, or continuation of, a contraceptive regimen.


METHODS
We searched computerized databases for trials that tested a theory-based intervention for improving contraceptive use (MEDLINE, POPLINE, CENTRAL, PsycINFO, EMBASE, ClinicalTrials.gov, and ICTRP). We also wrote to researchers to find other trials.


METHODS
Trials tested a theory-based intervention for improving contraceptive use. We excluded trials focused on high-risk groups. Interventions addressed the use of one or more contraceptive methods. The reports provided evidence that the intervention was based on a specific theory or model. The primary outcomes were pregnancy, contraceptive choice, initiating or changing contraceptive use, contraceptive regimen adherence, and contraception continuation.


METHODS
The primary author evaluated abstracts for eligibility. Two authors extracted data from included studies. We calculated the odds ratio for dichotomous outcomes and the mean difference for continuous data. No meta-analysis was conducted due to intervention differences.


RESULTS
Of 26 trials, 12 interventions addressed contraception (other than condoms), while 14 focused on condom use for preventing HIV or STIs. In 2 of 10 trials with pregnancy or birth data, a theory-based group showed better results. Four of nine trials with contraceptive use (other than condoms) showed better outcomes in an experimental group. For condom use, a theory-based group had favorable results in 14 of 20 trials, but the number was halved in a subgroup analysis. Social Cognitive Theory was the main theoretical basis for 12 trials, and 10 showed positive results. Of the other 14 trials, favorable results were shown for other social cognition models (N=2), motivational interviewing (N=5), and the AIDS Risk Reduction Model (N=2). No major patterns were detected by type of theory, intervention, or target population.


CONCLUSIONS
Family planning researchers and practitioners could apply the relevant theories and effective interventions from HIV and STI prevention. More thorough use of single theories would help inform the field about what works. Better reporting is needed on research design and intervention implementation.
Lopez
Laureen M
LM
Behavioral and Biomedical Research, Family Health International, P.O. Box 13950, Research Triangle Park, North Carolina 27709, USA. llopez@fhi.org
Tolley
Elizabeth E
EE
Grimes
David A
DA
Chen-Mok
Mario
M
D017280:Condoms / Q000706:statistics & numerical data; D003267:Contraception / Q000379:methods / Q000706:statistics & numerical data*; D003270:Contraceptive Agents / Q000008:administration & dosage*; D003274:Contraceptive Devices, Female / Q000706:statistics & numerical data; D005260:Female; D015658:HIV Infections / Q000517:prevention & control; D015438:Health Behavior; D006801:Humans; D008297:Male; D008962:Models, Theoretical; D016032:Randomized Controlled Trials as Topic; D012749:Sexually Transmitted Diseases / Q000517:prevention & control
D003270:Contraceptive Agents