How accurately were malaria rapid test results recorded in Nigerian health facilities?

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Malaria remains a major health concern in Nigeria, where health facilities widely use rapid diagnostic tests (RDTs) to confirm malaria before treatment. Concerns remain about whether healthcare workers follow and report the test results. The study compared RDT results recorded in facility registers in two Nigerian states with an unbiased reference standard and explored factors influencing agreement between raters.

Researchers conducted a mixed-method evaluation in 16 health facilities across Oyo and Sokoto States. RDTs performed by healthcare workers were photographed using a digital RDT reader and independently re-interpreted by a trained, independent, objective panel. Surveys of facilities and healthcare workers collected information on factors that might influence RDT recording. The researchers used Cohen’s kappa to assess agreement between the results recorded in facility registers and those interpreted by the external panel. They used a meta-analytical approach to calculate a pooled summary kappa across facilities and examined potential moderators of agreement, including characteristics of facilities, healthcare workers and RDTs.

Of 19,586 RDTs captured, 18,319 were included in the analysis. Overall, 6.2% of RDTs were misrecorded as positive and 3.7% as negative in facility registers; the positive predictive value was 87.2% (95% confidence interval [CI] 86.4%–87.8%) and the negative predictive value was 92.9%. Overall percentage agreement was 90.2% (95% CI 89.7%–90.6%), and the pooled kappa was 0.80 (95% CI 0.75–0.85), indicating strong agreement. Kappa values nevertheless varied substantially across facilities, from 0.59 to 0.92.

Agreement was lower in facilities in Sokoto State and in areas with lower malaria prevalence and test positivity. Faint test lines, found in 8.8% of RDTs, were associated with a significantly greater likelihood of results being misrecorded as negative. Healthcare workers were more likely to misrecord results as positive when a malaria diagnosis had been made or an antimalarial prescribed.

The researchers concluded that, despite strong overall agreement between facility registers and panel-interpreted RDT results, the proportions misrecorded as positive and negative highlight a need for better training, supportive supervision and mechanisms to promote accurate interpretation and recording. They said targeted interventions are essential for reliable routine malaria data and support for national control efforts.