Contraceptive efficacy is measured by
Contraceptive Efficacy: Is assessed by measuring the number of unplanned pregnancies that occur during a specified period of exposure and use of a contraceptive method. Two methods used are:

Pearl Index
Life table analysis

Life Table Analysis (LTA) as measure of contraceptive efficacy:
– LTA calculates a failure rate per month of use
– Better measure than PI
Pearl Index and Life table analysis
Pearl Index only
Life table analysis and Couple protection rate
Pearl Index and Couple protection rate
Pearl Index and Life table analysis