Failure rate of contraceptive method is determined by: (A) Pearl index, (B) Half life, (C) Number of accidental pregnancies, (D) Period of contraceptive practice continued
Answer is A. Two methods have been used to measure contraceptive efficacy: 1. Pearl index and 2. Life table analysis Pearl index is defined as the number of failure rates per 100 woman years of exposure Reference : Park&;s textbook of preventive and social medicine, 23rd edition, Page no: 510