Can mobile phone surveys accurately measure the coverage of maternal healthcare services? Results from the Rapid Mortality Mobile Phone Survey (RaMMPS) study in Mozambique

Abstract The COVID-19 pandemic raised the need for rapid approaches for measuring population-based health indicators to understand its impact on service utilization, while avoiding face-to-face interviews. The Rapid Mortality Mobile Phone Surveys (RaMMPS) aimed to test the use of mobile phone surveys (MPS) for measuring maternal health services coverage in Mozambique by comparing estimates to the nationally representative Demographic Health Survey 2022 (DHS 2022). RaMMPS used two strategies: 1) subsampling from existing national sample registration system, Countrywide Mortality Surveillance for Action (COMSA); 2) Random Digit Dialing (RDD) of randomly generated phone numbers. We collected data from March to August 2022 for the COMSA MPS sample, and from June to December 2022 for the RDD sample. In both cases computer assisted telephone interviews were conducted among women aged 15-49 years. Women were asked questions on utilization of maternal health care (MHC) services for births within two years preceding the survey. We compared adjusted MHC coverage estimates between each RaMMPS sample and the DHS 2022. Despite adjustment to redress the MPS samples, MHC coverage was higher in MPS samples compared to the DHS-2022 sample. The coverage of at least one antenatal care visit was 99% (95%CI: 98-99) in COMSA MPS and 98% (95%CI: 95-99) in RDD samples compared to 81% (95%CI: 79-84) in the DHS-2022 sample. Additionally, coverage of at least four antenatal care visits was 76% (95%CI: 73-80) in COMSA MPS and 85% (95%CI: 81-88) in RDD samples, compared to 48% (95%CI: 45-51) in the DHS-2022. Coverage of health facility delivery was 87% (95%CI: 84-90) in COMSA MPS and 90% (95%CI: 85-93) in RDD samples compared to 40% (95%CI: 38-62) in the DHS 2022. Similarly, skilled birth attendant coverage was 86% (95%CI: 82-89) and 88% (95%CI: 84-92) respectively in COMSA MPS and RDD samples compared to 48% (95%CI: 46-49) in the DHS 2022. MHC coverage measured through MPS were consistently overestimated compared to nationally representative surveys, even after adjustments.