James Trussell|David J. Portman
The creeping pearl: why has the rate of contraceptive failure increased in clinical trials of combined hormonal contraceptive pills?
Hull York Medical School|Princeton University|Columbus Center|The Ohio State University
despite several drawbacks pearl index continues widely used statistical measure contraceptive failure however pearl indices reported studies newer hormonal contraceptives appear increasingwe searched pubmed medical intelligence solutions databases prospective trials evaluating oral contraceptive oc efficacy examine potential factors could contribute increasing pearl indicesnumerous potential factors identified including increased rate failures newer ocs deficiencies methods calculating contraceptive failure rates differences study design changes patient populations resulting increased rates contraceptive failures due inappropriate inconsistent use methodthe two likely important contributors increase pearl indices frequent pregnancy testing sensitive tests less adherent study populations study populations appear increasingly representative likely actual users product marketed expect see even higher failure rates ongoing future studies result poses challenges companies regulatory agencies