ABSTRACT
INTRODUCTION: Limited information is available on the usefulness of the PIMA™ analyser in predicting antiretroviral treatment eligibility and outcome in a primary healthcare clinic setting in disadvantaged communities in KwaZulu-Natal, South Africa. MATERIALS AND METHODS: The study was conducted under the eThekwini Health Unit, Durban, KwaZulu-Natal. Comparison of the enumeration of CD4+ T-cells in 268 patients using the PIMA™ analyser and the predicate National Health Laboratory Services (NHLS) was undertaken during January to July 2013. Bland-Altman analysis to calculate bias and limits of agreement, precision and levels of clinical misclassification at various CD4+ T-cell count thresholds was performed. RESULTS: There was high precision of the PIMA™ control bead cartridges with low and normal CD4+ T-cell counts using three different PIMA™ analysers (%CV < 5). Under World Health Organization (WHO) guidelines (≤ 500 cells/mm3), the sensitivity of the PIMA™ analyser was 94%, specificity 78% and positive predictive value (PPV) 95%. There were 24 (9%) misclassifications, of which 13 were false-negative in whom the mean bias was 149 CD4+ T-cells/mm3. Most (87%) patients returned for their CD4 test result but only 67% (110/164) of those eligible (≤ 350 cells/mm3) were initiated on antiretroviral therapy (ART) with a time to treatment of 49 days (interquartile range [IQR], 42-64 days). CONCLUSION: There was adequate agreement between PIMA™ analyser and predicate NHLS CD4+ T-cell count enumeration (≤ 500 cells/mm3) in adult HIV-positive individuals. The high PPV, sensitivity and acceptable specificity of the PIMA™ analyser technology lend it as a reliable tool in predicting eligibility and rapid linkage to care in ART programmes.
ABSTRACT
Introduction: Limited information is available on the usefulness of the PIMATM analyser in predicting antiretroviral treatment eligibility and outcome in a primary healthcare clinic setting in disadvantaged communities in KwaZulu-Natal; South Africa.Materials and methods: The study was conducted under the eThekwini Health Unit; Durban; KwaZulu-Natal. Comparison of the enumeration of CD4+ T-cells in 268 patients using the PIMATM analyser and the predicate National Health Laboratory Services (NHLS) was undertaken during January to July 2013. Bland-Altman analysis to calculate bias and limits of agreement; precision and levels of clinical misclassification at various CD4+ T-cell count thresholds was performed.Results: There was high precision of the PIMATM control bead cartridges with low and normal CD4+ T-cell counts using three different PIMATM analysers (%CV 5). Under World Health Organization (WHO) guidelines (
