Measuring oral contraceptive knowledge: a review of research findings and limitations

Objective: Poor oral contraceptive (OC) knowledge may contribute to premature OC discontinuation and unintended pregnancy. Yet, to understand relationships between OC knowledge and contraceptive behavior, knowledge must be adequately measured. This review evaluates the findings and methodological limitations of research in which OC knowledge has been measured.

Methods: We performed a systematic review of primary research from January 1965 to January 2009. Studies were audited for study characteristics, purpose for measuring OC knowledge, key findings and measurement properties including administration method, knowledge domains, reliability, validity, health literacy and cultural sensitivity.

Results: We reviewed 21 studies: 18 cohort studies, including one psychometric evaluation, and three randomized trials. Results on OC knowledge outcomes were variable. Measures were largely self-administered survey (n=15) and lacked assessment of all OC knowledge domains. Information on measures' characteristics, reliability, validity, health literacy and cultural sensitivity was limited.

Conclusion: Existing OC knowledge measures lack critical psychometric elements, leading to inconsistent and unreliable findings.

Practice implications: Poor OC knowledge measurement precludes identifying counseling needs and developing interventions for contraceptive behavior change. Future research considerations include: measurement information in publications, psychometric evaluations, formal reliability/validity techniques, and attention to all OC knowledge domains, health literacy and cultural sensitivity.