Abstract Background Malaria remains a leading cause of morbidity and mortality among children under five years of age in Nigeria. While microscopy is the World Health Organization (WHO) gold standard for malaria diagnosis, rapid diagnostic tests (RDTs), such as the Standard Diagnostic Bioline Malaria Antigen Plasmodium falciparum (SD Bioline Malaria Ag P.f.), are increasingly used in healthcare and field settings. However, recent reports show variable performances of these tests, and evidence on their performance metrics from large, nationally representative Nigerian samples is limited. This study, therefore, aimed to evaluate the performance of the SD Bioline Malaria Ag P.f. RDT using a nationally representative dataset. Methods We conducted a secondary analysis of the 2021 Nigerian Malaria Indicator Survey (NMIS), a nationally representative household survey that used a two-stage stratified cluster sampling design. Children aged 6–59 months with valid results for both microscopy and SD Bioline Malaria Ag P.f were included. The performance metrics for the RDT were calculated against microscopy as the reference standard, accounting for the survey design. Results Among the surveyed children, a 9067-unweighted sample with complete RDT and microscopy test results was analyzed (weighted sample, n = 9131). The SD Bioline Malaria Ag P.f. demonstrated a sensitivity of 88.6%, a specificity of 75.2%, a positive predictive value (PPV) of 49.5%, a negative predictive value (NPV) of 96.0%, and an accuracy of 78.1%. Cohen’s kappa indicated moderate agreement with microscopy (κ = 0.496), and the overall weighted ROC AUC was 0.816. Conclusion SD Bioline Malaria Ag P.f . shows high sensitivity and negative predictive value, confirming its reliability for ruling out malaria in children aged 6–59 months in Nigeria. However, moderate specificity and low positive predictive value with a large microscopy-RDT estimated prevalence gap indicate a risk of overestimating malaria prevalence. False negatives may occur, potentially due to P f HRP2/3 deletions, test handling, or non-falciparum infections. These findings underscore the need for confirmatory testing where feasible, with the consideration of complementary diagnostic strategies to optimize surveillance and case management, and ongoing postmarketing evaluation of RDT performance.
Olubiyi et al. (Thu,) studied this question.