Bangladesh 1993-1994 Demographic and Health ... - Measure DHS

APPENDIX CDATA QUALITYThe purpose of this appendix is to provide the reader with an initial view of the general quality of theBDHS data. Appendix B is concerned with sampling errors and their effects on the survey results. The tablesin this appendix refer to possible non-sampling errors: digit preference, rounding or heaping on certain agesor dates; omission of events occurring farther in the past; deliberate distortion of information by someinterviewers in an attempt to lighten their work loads, etc. A description of the magnitude of such nonsamplingerrors is provided in the following paragraphs. The issues covered in this appendix are only lightlytouched on; many might qualify for more detailed study.C.IAge Reporting and Completeness of ReportingThe distribution of the de facto household population by single year of age is presented in Table C.1(see also Figure 2.2). The data show a preference for reporting ages that end in zeros and fives (age "heaping"or digit preference) that is commonly found in countries where ages are not known well. This tendency ismuch more prevalent in the age reporting for men than for women, perhaps because in many cases, thewomen themselves were the respondents for the household questionnaire and their ages were probed in moredetail since they were to be interviewed individually.There is litde evidence of a pattem, which has been observed in some DHS surveys, of interviewers"displacing" women outside of the eligible age range, presumably in order to avoid the need to interviewthem. In Bangladesh, all ever-married women age 10-49 were eligible for individual interview. There is noevidence of a heaping of girls at age 9 and a deficit at age 10; on the contrary, there is heaping at age 10,presumably due to the tendency to round ages to those ending in five or zero. There is evidence of someheaping of women on age 50; however, since it is much more exaggerated for men than women, it appearsthat there was little, if any, intentional displacement of women outside of the age range of eligibility. Thereis a somewhat greater bulge of women than men reported to be age 52, which may be evidence ofdisplacement to that age as opposed to age 50.Table C,2 shows that response rates vary little according to age of respondents. The percentdistribution of women interviewed is almost identical to that from the household questionnaire of evermarriedwomen by age. Also, the proportions of women interviewed are close to 100 percent (Table C.2, lastcolumn).Information on the completeness of reporting selected important variables is provided in Table C.3.Overall, the percentage of cases with missing information is extraordinarily low. Month of birth was missingfor less than one percent of births that occurred in the 15 years before the survey and both month and yearwere missing for one-tenth of one percent. Age at death was missing for an infinitesimal proportion of nonsurvivingbirths, as was prevalence of diarrhea among children under three. It should be noted thatcompleteness of reporting does not necessarily imply accuracy of reporting, since interviewers wereinstructed to probe to get ages and dates and, in some cases, to give their own best estimate rather than toallow the missing information to be imputed in the office.165