Demographic and Health Surveys Methodology - Measure DHS

d. Tabulation: Each sibling is tabulated three times, once according to her/his highest agegroup accumulating the exposure she/he contributes to that group, once in the middle agegroup accumulating middle age group exposure, and once in the lowest age groupaccumulating lowest age group exposure. (In CSPRO and ISSA, the same table is used,effectively summing the accumulations within each age group.)Once the numerators and denominators are properly established, age-specific mortality rates are obtainedby the division of the numerators by the corresponding denominators and multiplying by 1000. Thegeneral mortality rate for age 15-49 is obtained by multiplying the age-specific mortality rates by theproportion of respondents in the five-year age group and then summing the age-distribution-adjustedmortality rates.Handling of Missing ValuesSiblings whose survival status is unknown to the respondent are excluded from both numerators anddenominators. Dates of birth are calculated from current age for living siblings and age at death andnumber of years ago sibling died for dead siblings. Dates of birth and death are imputed where age, ageat death, or number of years ago is missing or unknown, taking into consideration of sibling’s birth orderand number of children (information collected for dead siblings only).Notes and ConsiderationsThe DHS maternal mortality module questionnaire collects information from respondents (female andmale about all of their siblings born to the same mother, starting with the oldest. For living siblings, thedate of birth in the recode data file is calculated by subtracting the age from the date of interview. Fordead siblings, the date of birth is calculated by subtracting the sum of the responses on age at death andthe number of years ago the death occurred from the date of interview. To calculate the date of death, thenumber of years ago the death occurred is subtracted from the date of interview. After these calculations,month of date of birth and date of death are assigned by subtracting a random number between 0 and 11and making sure that the birth order and minimum birth intervals are maintained.However, the age distribution of siblings is very much different than the age distribution of the populationsince only eligible women and men can report on their siblings. For example if a girl or boy is sixteenyears old and has only siblings younger than 15 years, she or he will not be reported. The same holds trueat the upper end of the eligible age range. Thus the age distribution of siblings is a curve with minimumsat the ends of the eligible age range of respondents and a maximum at about the midpoint of the eligibleage range (30 to 35 years). In order to properly calculate general or total rates, age-specific rates must beadjusted to a more representative age distribution. The distribution of respondents is used for thisadjustment.One might think that the calculation of mortality rates is biased because the (living) respondent is notincluded. Similarly, people with no siblings are not included since there is no one to report on them.However, it has been shown by German Rodriguez that these two potential biases cancel each other out,under the assumption that mortality rates are unrelated to the size of the sibship.Another important issue is location. The DHS does not collect information on the residence of neithersiblings who died nor of the residence during the exposure period of both living and dead siblings. Theresidence at the time of interview of respondents is not necessarily the same as that of their siblings.Therefore, DHS usually does not publish adult mortality rates by area.Guide to DHS Statistics 155 Updated September 2006