Best index of contraceptive efficacy is: (A) Pearl index, (B) Chandelers index, (C) Quetlet index, (D) Broca index
Answer is A. Pearl index is defined as the number of failures per 100 woman years of exposure (HWY) Failure rate per Hundred Women Years = Total accidental pregnancies X 1200/ Total months of exposure Reference : Park&;s textbook of preventive and social medicine, 23rd edition, Page no: 510