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

Figure 3.4Trends in the Total Fertility RateFrom Selected Sources, Bangladesh, 1980-1993Births per Womana2 . . . . . . ; . ' .80 81 82 83 84 85 87 8 89 91 92 g3YearNote: All survey rates are based on 3-year moving averages,except most recent year (2-year average)Source: Table 3.4Unlike survey data, the data from the Matlab district (Fable 3.4, last two columns) are collected ina surveillance system in which women are interviewed by field workers every two weeks. Thus, the data areless likely than survey data to suffer from recall error or problems in remembering or reporting dates. Thedemographic surveillance system covers a population of approximately 100,000 each in a "treatment" area,in which an intensive matemal and child health and family planning program has been in effect and a"comparison" area in which the residents receive the normal government and private health care (ICDDR,B,1994:2). Although data from Matlab are not nationally representative and therefore not comparable to datafrom the other sources, they do provide evidence of the unprecedented decline in fertility that has taken placein Bangladesh. Figure 3.5 shows the total fertility rates for the Matlab study area and the 1993-94 BDHSfertility rates for the period 1982 to 1993. The data from the BDHS and the Matlab comparison area showroughly comparable rates of decline over time, although, once again, the decline depicted from the BDHSis steeper than that from the surveillance system.The fact that the low fertility rates reported in the BDHS for the years immediately preceding thesurvey are not accompanied by a proportionately large increase in contraceptive use, in age at marriage, orin another of the major fertility determinants, invites an investigation into data quality. A review of the datareveals no obvious systematic errors such as omission or displacement of births that are often found in surveydata (see Appendix C.2). Moreover, a recent study in which data from a BDHS-type survey in the Matlabarea were compared with those from the ICDDR, B surveillance system, showed almost identical fertilityrates in the two sources, thus lending support to the BDHS fertilty data (see Appendix C.2). Some researchershypothesize that Bangladeshi surveys routinely underestimate recent fertility because women tend tooverreport the ages of their young children (Cleland et at., 1993:14; Cleland et al., 1994:17,18). To the extentthat such age overreporting is random--that is, not selective of women with certain characteristics--it wouldnot be readily detectable in the data. However, if age overreporting is a widespread cultural phenomenon,it would presumably have also affected the fertility rates reported in prior surveys. Thus, although the levelof the total fertility rate reported in the BDHS for the years immediately preceding the survey may beunderestimated, if rates from previous surveys were similarly affected, the data nonetheless indicate anextremely rapid decline in fertility in Bangladesh over the past two decades.29