Theory-based interventions for contraception
Editorial Group: Cochrane Fertility Regulation Group
Published Online: 7 AUG 2013
Assessed as up-to-date: 3 JUL 2013
Copyright © 2013 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
How to Cite
Lopez LM, Tolley EE, Grimes DA, Chen M, Stockton LL. Theory-based interventions for contraception. Cochrane Database of Systematic Reviews 2013, Issue 8. Art. No.: CD007249. DOI: 10.1002/14651858.CD007249.pub4.
- Publication Status: New search for studies and content updated (no change to conclusions)
- Published Online: 7 AUG 2013
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.
Review randomized controlled trials (RCTs) that tested a theoretical approach to inform contraceptive choice; encourage contraceptive use; or promote adherence to, or continuation of, a contraceptive regimen.
Through June 2013, we searched computerized databases for trials that tested a theory-based intervention for improving contraceptive use (MEDLINE, POPLINE, CENTRAL, PsycINFO, ClinicalTrials.gov, and ICTRP). Previous searches also included EMBASE. For the initial review, we wrote to investigators to find other trials.
Trials tested a theory-based intervention for improving contraceptive use. We excluded trials focused on high-risk groups and preventing sexually transmitted infections or HIV. Interventions addressed the use of one or more contraceptive methods for contraception. The reports provided evidence that the intervention was based on a specific theory or model. The primary outcomes were pregnancy, contraceptive choice or use, and contraceptive adherence or continuation.
Data collection and analysis
The primary author evaluated abstracts for eligibility. Two authors extracted data from included studies. For the dichotomous outcomes, the Mantel-Haenszel odds ratio (OR) with 95% CI was calculated using a fixed-effect model. Cluster randomized trials used various methods of accounting for the clustering, such as multilevel modeling. Most reports did not provide information to calculate the effective sample size. Therefore, we presented the results as reported by the investigators. No meta-analysis was conducted due to differences in interventions and outcome measures.
We included three new trials for a total of 17. Ten randomly assigned individuals and seven were cluster-randomized. Eight trials showed some intervention effect.
Two of 12 trials with pregnancy or birth data showed some effect. A theory-based group was less likely than the comparison group to have a second birth (OR 0.41; 95% CI 0.17 to 1.00) or to report a pregnancy (OR 0.24 (95% CI 0.10 to 0.56); OR 0.27 (95% CI 0.11 to 0.66)). The theoretical bases were social cognitive theory (SCT) and another social cognition model.
Of 12 trials with data on contraceptive use (non-condom), six showed some effect. A theory-based group was more likely to consistently use oral contraceptives (OR 1.41; 95% CI 1.06 to 1.87), hormonal contraceptives (reported relative risk (RR) 1.30; 95% CI 1.06 to 1.58) or dual methods (reported RR 1.36; 95% CI 1.01 to 1.85); to use an effective contraceptive method (reported effect size 1.76; OR 2.04 (95% CI 1.47 to 2.83)) or use more habitual contraception (reported P < 0.05); and were less likely to use ineffective contraception (OR 0.56; 95% CI 0.31 to 0.98). Theories and models included the Health Belief Model (HBM), SCT, SCT plus another theory, other social cognition, and motivational interviewing (MI).
For condom use, a theory-based group had favorable results in 5 of 11 trials. The main differences were reporting more consistent condom use (reported RR 1.57; 95% CI 1.28 to 1.94) and more condom use during last sex (reported results: risk ratio 1.47 (95% CI 1.12 to 1.93); effect size 1.68; OR 2.12 (95% CI 1.24 to 3.56); OR 1.45 (95% CI 1.03 to 2.03)). The theories were SCT, SCT plus another theory, and HBM.
Nearly all trials provided multiple sessions or contacts. SCT provided the basis for seven trials focused on adolescents, of which five reported some effectiveness. Two others based on other social cognition models had favorable results with adolescents. Of six trials including adult women, five provided individual sessions. Some effect was seen in two using MI and one using the HBM. Two based on the Transtheoretical Model did not show any effect.
Eight trials provided evidence of high or moderate quality. Family planning researchers and practitioners could adapt the effective interventions, although most provided group sessions for adolescents. Three were conducted outside the USA. Clinics and low-resource settings need high-quality evidence on changing behavior. Thorough use of single theories would help in identifying what works, as would better reporting on research design and intervention implementation.
Plain language summary
Improving birth control use with programs based on theory
Theories and models help explain how behavior change occurs. HIV-prevention research has used theories and models. Programs to prevent sexually transmitted infections (STIs) are often based on behavioral science. The health field has used many theories and models of change. However, programs that address birth control often have no stated theory base.
Through June 2013, we did computer searches to find randomized controlled trials that tested a theory-based program to improve birth control use. We also wrote to investigators to find other trials.
Trials tested a theory-based program for improving birth control use. We excluded trials focused on high-risk groups and programs to prevent sexually transmitted infections or HIV. Programs addressed the use of one or more birth control methods. The reports showed that the theory or model was part of the program design. The comparison could be another program based on theory, usual care, or no intervention.
The main outcomes were pregnancy, choice of birth control method, change in birth control use, and continuing to use birth control. We did not combine any trials since the programs differed from each other.
We added three new trials in this update for a total of 17 studies. Nearly all provided several sessions or contacts. Twelve trials had pregnancy or birth data and two had better results for a theory-based group. Of 12 trials with data on birth control use (non-condom), six showed better use in a treatment group. For condom use, a theory-based group had better results in 5 of 11 trials. Social cognitive theory was the basis for seven trials focused on teenagers, and five showed some effect. Two based on other social cognition models had good results with teens. Of six trials with women older than teens, five had individual sessions. Some effect was shown in two using motivational interviewing and one using the health belief model.
Eight trials were rated as having good quality. Researchers and health care providers could use the programs that worked in their settings. Most focused on teenagers and had group sessions. We need good research on preventing pregnancy for clinics and places with low resources. Clearer use of one theory would help in seeing what works. Better reporting would help in knowing how the research was done and the program was provided.