title: Correcting contraceptive failure rates for sample composition and sample section bias.
mesh_terms: D000293:Adolescent; D000328:Adult; D002755:Choice Behavior; D003267:Contraception; D003268:Contraception Behavior; D005260:Female; D006801:Humans; D008960:Models, Psychological; D011247:Pregnancy; D012107:Research Design / Q000592:standards*