Impact evaluation of long-lasting insecticidal nets distribution campaign on malaria cases reported at outpatient departments across all the regions in Ghana

BACKGROUND: Malaria remains the biggest public health challenge globally, and Ghana is among the 15 highest burden malaria countries in the world, with 2% of global malaria cases and 3% deaths in 2019. This study sought to assess the impact of mass LLIN distribution campaign on malaria morbidity using all health facilities outpatient data across 15 regions of Ghana. METHODS: Data for this study was obtained from the DHIMS2 for health facilities providing OPD and malaria services in Ghana. This was an ecological study that employed the difference-in-difference approach to assess the change in proportion of uncomplicated confirmed malaria cases among OPDs in all types of health facilities in Ghana between 2015 and 2019 following the mass distribution campaign of LLINs in 2018. Malaria cases at the OPDs before and after the free LLIN mass distribution exercise were evaluated. RESULTS: The trend of the proportion of OPD cases that were confirmed uncomplicated malaria cases increased from 14.8% in 2015 to 18.9% in 2019 at the national level. The average proportion of malaria cases among OPDs in Ghana in 2019 reduced against the expected by − 3.76% (95% CI − 4.69 to − 2.84], p<0.001) among all cases, − 4.52% (95% CI [− 5.70 to − 3.34], p<0.001) among children under-fives years, − 4.10% (95% CI − 5.3 to 2.9], p<0.001) among female children under-five and − 5.18% (95% CI [− 6.33 to − 4.02], p<0.001) among male children under-five. The reduction on the average proportion of malaria cases among OPDs varied significantly across regions and the type of health facilities. CONCLUSION: The mass distribution of LLINs across Ghana in 2018 can be associated with reduction in the proportion of malaria cases among OPDs across health facilities in Ghana. The study recommends the biannual mass distribution campaigns especially in the high-density regions.