Performance and Cost Comparison of a Rapid Diagnostic Test for Malaria and Microscopy. A Cross-Sectional Diagnostic Study

Background: The shift from traditional microscopy to rapid diagnostic tests (RDTs) for malaria diagnosis is gaining popularity, especially in resource-limited settings with unstable electricity and limited expertise. However, trust issues arise due to the inconsistent performance of different RDT kits. Objectives: This study identified the variations in performance and cost of an RDT brand for malaria among different population demographics: pregnant women, young children, and adults, when compared with microscopy as a gold standard. Method: The research was carried out in northwestern Nigeria and involved 360 participants stratified into 3 groups: children (5–17 years), adults (≥ 18 years), and pregnant women. Samples were analyzed using both RDT and microscopy. Cost data were gathered from retrospective study expenses. Results: The RDT showed higher sensitivity (86.1%) and positive predictive value (PPV) of 87.9% in children, but lower sensitivity (59.5%) and specificity (54.3%) in pregnant women. Logistic regression indicated that the likelihood of testing positive decreased by 2% with each year of age (p-value = 0.014), 10% decrease with each increase in unit of BMI (p-value < 0.001), and twice the odds of positivity in those with vomiting (p-value = 0.004). RDT had lower labor costs at ₦61 than microscopy at ₦746, which requires higher technical expertise. Conclusion: RDTs offer a rapid malaria diagnostic option. In resource-constrained settings, they may be suitable for certain populations, such as children or adults. However, their limitations in pregnant women and the impact of age and BMI on accuracy necessitate supplementary tests where resources permit.