Afghanistan Mortality Survey 2010 - Measure DHS

3.1.2 Data Quality AssessmentThe pregnancy history data obtained in the AMS 2010 are subject to several sources of errors thatare inherent in efforts to obtain retrospective data on women’s childbearing experience. First, the data areaffected by women’s willingness to report on all of the pregnancies they had in their lifetime. Womenmay find it painful to discuss pregnancies that ended in miscarriages or stillbirths, or report on childrenwho were born alive but later died. Women, particularly older women who are being asked to report onevents that occurred over several decades, also may simply not recall some events, especially those thatoccurred early in their reproductive lives. Interviewers may also fail to record some events women reportto lighten their workload. Whatever the source, if omission (the failure to report pregnancies) occursfrequently, it can seriously bias estimates of the level of fertility. If there is a tendency todisproportionately omit stillbirths or children who have died, it may also affect mortality levels.Another common source of error in pregnancy history data arises from the difficulties inobtaining accurate information on dates of birth, ages at which children died or the number of months awoman was pregnant when the pregnancy terminated. Such data can be very problematic to collect insettings such as Afghanistan where literacy levels are low. To the extent that errors in reportinginformation are due to poor recall, they generally tend to be greater the further back in time that thepregnancy occurred. Displacement also can be the result of deliberate misreporting of birth dates byinterviewers. This typically occurs if sections of a questionnaire are administered only for children bornafter a certain date—which is the case in the AMS 2010—and interviewers may seek to reduce theirworkload by moving the dates of birth of children born in the period of interest back in time to avoidasking these questions. Whatever the source, errors in the reporting of birth dates can cause a distortion inthe time trends in fertility and mortality estimates while errors in reporting ages at death can adverselyaffect the age pattern of mortality.A number of data quality tables were run to assess the extent of omission and displacement in theAMS 2010 birth history data. Those tables are presented in Appendix C. In the discussion that follows,the focus is on how data quality issues may affect the fertility estimates.Omissions can be difficult to detect and quantify. One sign of potential omission is an abnormalsex ratio at birth. The sex ratio, typically expressed as the number of males per 100 females, is expectedto be around 103-106 at birth. Sex ratios for Afghanistan and for the North, Central and South zones arepresented in Appendix Table C.5. For Afghanistan as a whole, the sex ratios at birth for various calendaryearperiods before the AMS uniformly exceed the normal ratio, implying a consistent underreporting offemale births. For example, for the most recent calendar period 2006-2010 (1385-1389 in the Afghancalendar), the ratio is 115.7, around 10 percent above the normal sex ratio. An adjustment for thesemissing female births would result in an increase of about 5 percent in the total number of births. The sexratios for the South zone are more exaggerated than those for the North and Central zones, suggesting amuch greater tendency to underreport female births in the South zone than in the other areas.Figure 3.1 presents the distribution of live births by the number of years prior to the survey. Anoticeable drop in the number of births is evident in the two-year period immediately prior to the survey,which comprises two of the three years on which the current fertility estimates discussed later in thechapter are based. The drop is more pronounced in the South zone than in the North and Central zonescombined. This pattern likely results from a combination of falling fertility and underreporting (omission)of births, but ascertaining the relative contribution of each of these components is not possible with thedata available.38 | Fertility, Marriage, and Family Planning