Effectiveness of antimalarial interventions in Nigeria: Evidence from facility-level longitudinal data.

Abstract

To evaluate the effectiveness of a program of antimalarial interventions implemented in 2010-2013 in Niger State, Nigeria. Utilization reports from 99 intervention and 51 non-intervention health facilities from the Niger State Malaria Elimination Program, supplemented by data on facility-level characteristics from the Niger State Primary Health Care Development Agency and Local Government Malaria Control units. Estimated with mixed-effects negative binomial modeling, a difference-in-differences method was used to quantify the impact of the program on the number of febrile illness cases and confirmed malaria cases. Potential confounding factors, non-stationarity, seasonality, and autocorrelation were explicitly accounted for. Data were retrieved from hard copies of utilization reports and manually inputted to create a panel of 5550 facility-month observations. The program was implemented in two phases. The first phase (August 2010-June 2012) involved the provision of free artemisinin-based combination therapies, long-lasting insecticidal nets, and intermittent preventive treatments. In the second phase (July 2012-March 2013), the program introduced an additional intervention: free parasite-based rapid diagnostic tests. Compared to the pre-intervention period, the average number of monthly febrile illness and malaria cases increased by 20.876 (P<0.01) and 22.835 (P<0.01) in the first phase, and by 19.007 (P<0.05) and 19.681 (P<0.05) in the second phase, respectively. The results are consistent across different evaluation methods. This study suggests that user-fee removal leads to increased utilization of antimalarial services. It motivates future studies to cautiously select their investigative methods.