A review of problems of bias and confounding in epidemiologic studies of cervical neoplasia and oral contraceptive use.
D003274:Contraceptive Devices, Female; D003276:Contraceptives, Oral / Q000009:adverse effects*; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D012306:Risk; D002583:Uterine Cervical Neoplasms / Q000139:chemically induced* / Q000175:diagnosis
D003276:Contraceptives, Oral