Background: Full birth histories (FBHs) are a key tool for estimating fertility and child mortality in low-and middle-income countries, but they are lengthy to collect. This is not desirable, especially for rapid turnaround surveys that ought to be short (e.g., mobile phone surveys). To reduce the length of the interview, some surveys resort to truncated birth histories (TBHs), where questions are asked only on recent births.
Methods: We used 29 Malaria Indicator Surveys from 17 countries in Sub-Saharan Africa to compare full and truncated birth histories. Each set of TBHs was paired and compared to an overlapping set of FBHs. We conducted a variety of data checks, including a comparison of the proportion of children reported in the reference period and a comparison of the fertility and mortality estimates.
Results: Fertility and mortality estimates from TBHs are lower than those based on FBHs. These differences are driven by the omission and displacement of births outside the reference period.
Conclusions: TBHs are prone to misreporting errors that will bias both fertility and mortality estimates. These errors are not systematically associated with interviewer characteristics, but data quality markers correlate with respondent attributes, suggesting that truncation creates confusion among respondents. Rigorous data quality checks should be put in place when collecting data through this instrument in future surveys.