Characteristics of the Cavidi^® reverse transcriptase assay for detecting HIV viral loads ≥400 copies/mL using RNA PCR or branched DNA assay (bDNA) assays in patients receiving antiretroviral therapy.

a95% CI, 95% Confidence Interval. bSensitivity of the RT assay was the proportion of patients at baseline with RT assays ≥400 eq copies/ml among those with viral loads ≥400 copies/ml using RNA PCR or bDNA assays. Specificity of the RT assay was the proportion of patients at week 36 or 48 of treatment (which ever was the last value) with undetectable RT activity among those with viral loads <400 copies/ml using RNA PCR or bDNA assays. bDNA data from nine patients were excluded due to technical errors in one run. cPositive and negative predictive values were calculated using a 22% prevalence (18 of 83 patients with RNA PCR available after week 24) of a detectable RNA PCR viral load at week 36 or 48 of therapy; a sensitivity of 100% and specificity of 95% for the RNA PCR assay and a sensitivity of 100% and a specificity of 90% for the bDNA assay.