You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is True about pearl index: and explain in detail?
Ans. (d) Contraceptive failureRef: Park's PSM 21sted. 1472* Pearl index is used to measure the contraceptive efficacy/ contraceptive failure.* It is defined as the number of failures per 100 women- years (HWY) of exposure.P/ =Total accidental pregnancies------------------------Total months of exposurex 1200* Another method used to measure contraceptive failure/ efficacy is life table analysis.* Life table analysis: calculates failure rates for each month of use.