Accuracy of self-screening for contraindications to combined oral contraceptive use

OBJECTIVE: To estimate how well a convenience sample of women from the general population could self-screen for contraindications to combined oral contraceptives using a medical checklist.

METHODS: Women 18-49 years old (N=1,271) were recruited at two shopping malls and a flea market in El Paso, Texas, and asked first whether they thought pills were medically safe for them. They then used a checklist to determine the presence of level 3 or 4 contraindications to combined oral contraceptives according to the World Health Organization Medical Eligibility Criteria. Women were then interviewed by a blinded nurse practitioner who also measured blood pressure.

RESULTS: The sensitivity of the unaided self-screen to detect true contraindications was 56.2% (95% CI: 51.7%-60.6%) and specificity 57.6% (54.0%-61.1%). The sensitivity of the checklist to detect true contraindications was 83.2% (79.5%-86.3%) and specificity 88.8% (86.3%- 90.9%). Using the checklist, 6.6% (5.2%-8.0%) of women incorrectly thought they were eligible for use when, in fact, they were contraindicated, largely due to unrecognized hypertension. Seven percent (5.4%-8.2%) of women incorrectly thought they were contraindicated when they truly were not, primarily due to misclassification of migraine headaches. In regression analysis, younger women, more educated women and Spanish-speakers were significantly more likely to correctly self-screen (p<0.05).

CONCLUSION: Self-screening for contraindications to oral contraceptives using a medical checklist is relatively accurate. Unaided screening is inaccurate and reflects common misperceptions about the safety of oral contraceptives. Over-the-counter provision of this method would likely be safe, especially for younger women and if independent blood pressure screening were encouraged.