Improving the quality of adult mortality data collected in demographic surveys: a randomized trial in Niakhar (Senegal)

In sub-Saharan and south Asian countries with incomplete vital registration, adult mortality rates are estimated by asking respondents of household-based surveys (e.g., DHS) about the survival of their maternal siblings. These siblings' survival histories (SSH) are inexpensive to collect but are affected by biases, including sample selection and recall biases. Statistical adjustments have been proposed to correct for sample selection biases, but respondent errors (e.g., forgetting of siblings) are considered inevitable. We test whether a new survey instrument - the siblings enhanced life calendar (SELC) – improves the quality of mortality data relative to standard instruments currently used in DHS surveys. The SELC is based on a life history calendar, a tool widely used in other areas of survey research (e.g., migration histories, sexual behavior research) but not to improve the recall of adult mortality data in developing countries. It also incorporates recall cues developed through cognitive interviews. We report results of a randomized trial of the SELC conducted in a rural population of Senegal (Niakhar) that has been under demographic surveillance (DSS) for the past 50 years. To compare error rates in each arm of the trial, we link DSS data (our “gold standard”) to SSH and SELC data at the individual level.