Collecting mortality data via mobile phone surveys: a non-inferiority randomized trial in Malawi

Introduction Despite the urgent need for timely mortality data in low-income and lower-middle-income countries, mobile phone surveys rarely include questions about recent deaths. There are concerns that such questions might a) be too sensitive, b) prompt negative/adverse reactions among respondents, c) take too long to ask and/or d) generate unreliable data. We assessed the feasibility of mortality data collection during mobile phone surveys. Methods We conducted a non-inferiority trial among a random sample of mobile phone users in Malawi. Participants were allocated 3:1 to an interview about recent deaths in their family (treatment group) or about their economic activity (control group). In the treatment group, half of the respondents completed a short mortality questionnaire, focused on information necessary to calculate recent mortality rates, whereas the other half completed an extended questionnaire that also included questions about symptoms and healthcare use. The primary trial outcome was the cooperation rate. Secondary outcomes included the completion rate, self-reports of negative feelings and stated intentions to participate in future interviews. We also documented the amount of time required to collect mortality data, and we explored the quality of death reports. Results The difference in cooperation rates between treatment and control groups was 0.9 percentage points (95% CI = -2.3, 4.1), which satisfied the non-inferiority criterion. Similarly, the mortality questionnaire was non-inferior to the control questionnaire on all secondary outcomes. Collecting mortality data required approximately 2 to 4 additional minutes per reported death, depending on the inclusion of questions about symptoms and healthcare use. More than half of recent deaths elicited during mobile phone interviews had not been reported to the national civil registration system. Conclusion Including mortality-related questions in mobile phone surveys appears acceptable and feasible. It might help strengthen the surveillance of mortality trends in low-income and lower-middle-income countries with limited civil registration systems. KEY QUESTIONS What is already known? In many low-income and lower-middle-income countries, civil registration systems only record a fraction of all deaths. The excess mortality associated with health crises is thus not known in near real-time. Mobile phone surveys are increasingly common in low-income and lower-middle-income countries. They could help fill mortality-related data gaps, but there are concerns that asking questions about recent deaths over the phone might be too sensitive, might take too long, and/or might generate unreliable data. What are the new findings? In a randomized trial conducted with mobile phone users in Malawi, asking questions about recent deaths was not less acceptable than asking questions about economic activity and household livelihoods. Few participants reported experiencing negative feelings during the interview, and these feelings were temporary. More than half of the deaths reported during mobile phone interviews had not been previously registered with the national civil registration system. What do the new findings imply? Including questions about recent deaths in mobile phone surveys appears feasible and acceptable. It might help strengthen the surveillance of mortality trends in low-income and lower-middle-income countries with limited civil registration systems.