Demographic and Health Surveys Methodology - Measure DHS

Handling of Missing ValuesThe total number of children to which a woman has given birth is recorded obligatorily by theinterviewer; no unknown numbers of children are allowed. There are six values involved in thecalculation of ASWFR: interview date, birth date of woman, birth dates of children, survival of children,ages at death of dead children, and ideal number of children. The interview date is always known fromfieldwork dates. If missing or unknown, the birth dates of interviewed women and her children areimputed before the formation of the standard recode file. See Croft, 1999 on date imputation. Children’ssurvival statuses are not allowed to be missing. For dead children with missing age at death, the age atdeath in months is imputed in the standard recode dataset, using a hot deck technique based on birthorder. See Croft, 1999 for the imputation procedure.For ideal number of children, non-numeric and “don’t know” responses are considered to be highnumbers, so that all births are considered wanted. Births to women with missing information on idealnumber of births are considered as unwanted.Notes and ConsiderationsThe calculation of age-specific and total wanted fertility rates is the same as age-specific and total fertilityrates with the addition classification of births to wanted or not wanted at the time of conception.Births to women younger than 15 years or older than 49 years at the time of the birth are not generallyincluded. In a few specific countries, births to girls 10–14 are included.Births in the month of interview are excluded. This exclusion is because this month does not represent afull month, but is censored by the date of interview.A three-year (36 month) time period is taken for calculating current AWFSR. This period is acompromise between the need for recency and reduction of sampling variation. This time period wasselected during the World Fertility Survey, when sample sizes usually comprised about 5,000 women. Forcomparability over time and across surveys, this period has been maintained by DHS.No adjustment is made for truncation by age. (Women who are at most 49 years old at the time of theinterview were 48 years old the year before and 47 years old two years before.) The reason no adjustmentis made is that the tiny probability of giving birth by women 48 and 49 years of age outweighs thecomplication of doing the adjustment by single year of age.In line with general DHS policy, no adjustment is made for possible omission or date misreporting of thedates of birth of children or misreporting of the date of birth of the woman.For ever-married samples, it is assumed that never-married women have not had any births. Only thedenominator of the rates is adjusted to estimate the number of all women.ReferenceCroft, T. 1991. Date Editing and Imputation. Demographic and Health Surveys World ConferenceProceedings, II: 1337–1356, Columbia, Maryland: IRD/ORC Macro.Guide to DHS Statistics 89 Updated September 2006