Best index for measuring contraceptive efficacy is: (A) Pearl index, (B) Life-table analysis, (C) Chandler's index, (D) Quetlet index
Answer is B. Life table analysis : Calculates a failure rate for each month of use Cumulative failure rate can then compare methods of any specific length of exposure Women who leave a study for any reason other than unintended pregnancy are removed from analysis, contributing their exposure until the time of exit Reference : Park&;s textbook of preventive and social medicine, 23rd edition, Page no: 510