Demographic and Health Surveys Methodology - Measure DHS

B. Denominator: Number of all births (last and other) grouped by two-month intervals beforesurvey, as determined by difference in interview date and birth date (in CMC).C. Percentages: Numerators are divided by the denominator and multiplied by 100.Handling of Missing Values1. Birth dates were imputed if missing. Dates of interview are not allowed to have missing data.2. Women with missing reports of amenorrhea or sexual abstinence are considered to be notamenorrheic or not abstaining, respectively.Notes and ConsiderationsAssumptionsOnly the last of multiple births are considered. The other births are ignored in both numerators anddenominator.Births of both living and dead children are included. Survival status is ignored.Statistics: Median and Mean Durations of Postpartum Amenorrhea, Abstinence,and InsusceptibilityDefinitionA. Coverage:Calculation1. Population base: All births in the time period 0 to 35 months before the survey.2. Time period: Current status at the time of the survey (interview date).Utilize the numerators and denominators calculated for the proportions amenorrheic, abstaining andinsusceptible by time since birth, as given above. Numerators and denominators are each smoothed by athree-group moving average. For example, the value of the numerator and denominators for births thatoccurred 4–5 months before the interview is the average of groups 2–3, 4–5, and 6–7 months. Groups< 2 months and 34–35 months are not smoothed. Smoothed proportions are calculated by dividing thesmoothed numerator values by the smoothed denominator values of each two-month group.MedianBeginning with the lowest-time-since-birth group, each group is examined to see whether the proportionamenorrheic, abstaining, or insusceptible is less than 0.5. Value of median is determined by linearinterpolation of percentage of first group below 0.5 and previous group percentage using the followingformula:median = m i-1 + (p i-1 – 0.5)/(p i-1 – p i ) x (w i),Guide to DHS Statistics 74 Updated September 2006