Determinants of Facility-Level Use of Electronic Immunization Registries in Tanzania and Zambia: an Observational Analysis.

Background: As more countries transition from paper-based to electronic immunization registries (EIRs) to collect and track individual immunization data, guidance is needed for successful adoption and use of these systems. Little research is available on the determinants of EIR use soon after introduction. This observational study assesses the determinants of facility health care workers' use of new EIRs in Tanzania and Zambia, implemented during 2016 to 2018. Methods: We used EIR data entered between 2016 and 2018 from 3 regions in Tanzania and 1 province in Zambia to measure weekly EIR system use for a total of 50,639 facility-weeks. We joined secondary data on facility characteristics and applied the Performance of Routine Information System Management framework to categorize characteristics as organizational, technical, or behavioral. We used a generalized estimating equations logistic regression model to assess facility characteristics as potential determinants of system use. Results: In both countries, the estimated odds of weekly EIR use declined weekly after EIR introduction. In Tanzania, health centers and hospitals had increased odds of system use compared to dispensaries. For each additional health care worker trained in a facility during the EIR introduction, the estimated odds of weekly EIR use increased. Tanzanian facilities that had transitioned entirely to paperless reporting had higher odds of sustained use compared to those maintaining parallel electronic and paper-based reporting systems. In Zambia, distance from the district health office was significantly associated with decreasing odds of system use. There were significant differences in EIR use by district in both countries. Discussion: The results highlight the importance of organizational and behavioral factors in explaining sustained EIR use. As EIRs are introduced in new settings, we recommend indicators of engagement and use be built directly into the system so they can be routinely monitored, and course corrections can be implemented as needed.