Number of infants linked to ART after false-positive diagnosis, per 1,000 ART initiations, by assay specificity and MTCT risk.

<p>Multivariate sensitivity analysis varying specificity of the NAAT and infant HIV prevalence modelled by increasing MTCT risk. The vertical axis shows the number of infants with false-positive diagnosis initiating ART, per 1,000 ART initiations. Groups of coloured bars indicate 3 values for infant HIV prevalence at weaning (12 months of age): purple indicates a low MTCT risk scenario, with 12-month risk of 1.3%; green indicates the base-case value of 4.9%; and blue indicates a high MTCT risk scenario, with risk of 9.6%. Three values of NAAT specificity are shown within each MTCT risk scenario. For each combination of MTCT risk and NAAT specificity, bars indicate those who are truly HIV-uninfected (false-positive diagnosis). The left, dark-coloured bar in each pair reflects the outcome without confirmatory testing, and the right, light-coloured bar reflects the outcome with confirmatory testing. ART, antiretroviral therapy; EID, early infant diagnosis; MTCT, mother-to-child transmission; NAAT, nucleic acid amplification test.</p

Selected data parameters for CEPAC–Pediatric model analysis of early infant HIV diagnosis testing in South Africa.

<p>Selected data parameters for CEPAC–Pediatric model analysis of early infant HIV diagnosis testing in South Africa.</p

Implementation scenario model results: Early infant HIV diagnosis testing at 6 weeks in South Africa with and without confirmatory testing.

<p>Implementation scenario model results: Early infant HIV diagnosis testing at 6 weeks in South Africa with and without confirmatory testing.</p

Base-case model results: Early infant HIV diagnosis testing at 6 weeks in South Africa with and without confirmatory testing.

<p>Base-case model results: Early infant HIV diagnosis testing at 6 weeks in South Africa with and without confirmatory testing.</p

Univariate sensitivity analyses examining the impact of variation in individual input parameters on the difference in cost per HIV-exposed infant between the without and with confirmatory testing strategies.

<p>Key parameters varied in sensitivity analyses are shown on the left. Values in parentheses indicate the range examined (from the value leading to the lowest difference in cost to the value leading to the greatest difference, with base-case values after the semicolon). The horizontal axis shows the difference in cost between the 2 strategies: without confirmatory testing minus with confirmatory testing. The bounds of the blue bar indicate the cost differences at the extreme parameter values; longer bars therefore indicate parameters to which the model results were more sensitive. Where confidence intervals were available for the primary data estimates used in the base case, we indicate the bounds of these confidence intervals with brackets overlying the blue bars; the distance between brackets therefore indicates the degree to which the base-case estimates are affected by parameter uncertainty. The blue bar reaches the far left axis (indicating a cost difference of 0) at the threshold value for each parameter where confirmatory testing is no longer cost-saving compared to without confirmatory testing. The grey vertical line indicates the value for each parameter at the base-case result: a savings of US$40 per infant with confirmatory testing. ART, antiretroviral therapy; EID, early infant diagnosis; NAAT, nucleic acid amplification test.</p

Total lifetime costs per HIV-exposed infant by EID strategy.

<p>Columns include components of lifetime total costs per HIV-exposed infant tested: routine HIV care, CD4 and HIV viral load monitoring, OIs and end-of-life care, ART, EID costs, and false-positive costs. EID programme costs are shown in blue and comprise 2%–3% of lifetime costs, as shown previously [<a href="http://www.plosmedicine.org/article/info:doi/10.1371/journal.pmed.1002446#pmed.1002446.ref021" target="_blank">21</a>]; false-positive costs are shown in orange and are made up of all component costs acquired for HIV-infected infants other than OI costs. ART, antiretroviral therapy; EID, early infant diagnosis; FP, false-positive; OI, opportunistic infection.</p