Table 1.
CD4 tiers in Pixley-ka-Seme.
Figure 1.
Breakdown of individual cost components, i.e. equipment, reagent and staff costs, used to derive cost per test, at baseline error rates per tier (12% for Tier-1; 8% for Tier-2 and 1% for Tiers 3–5). Daily workload is graphically represented. Existing (Tier-4 and Tier-5) and proposed tiers (Tier-1, or Tier-2 or Tier-3) is shown, as well as service tiers that use POC technologies to CD4 deliver services.
Figure 2.
Relationship between costs, TAT and volumes.
Comparison of expected laboratory-to-result turnaround-time (LTR-TAT, orange) and annual CD4 workload (test volumes, blue), per tier, versus cost-per-result (in US$). Tier 3, 4 and 5 laboratories with higher volumes have a lower cost but associated longer LTR-TAT, versus the POC tiers (Tiers 1 and 2) with fast TAT but cost 2–4 times more. Tier-3 emerges with the lowest cost despite lower workload but still meets <24-hour LTR-TAT and fulfils NDOH treatment algorithm requirements [5] where patients are requested to return for CD4 results at 7 days. (*Tiers 1, 2 and 3 are proposed services, #Tiers 4 and 5 are existing service tiers).
Figure 3.
Sensitivity analysis for POC tiers indicating the impact of test volume, error rates and cartridge costs on cost-per-result. (High error rates of 10 and 15% for Tiers 2 and 1 respectively and low error rates of 6 and 9% per POC tier were used). Baseline cost for Tier-1 (upper dotted line), Tier-2 (lower dotted line) and Tier-3 (feint dotted line) is displayed for reference. This analysis confirms that POC cost is dependent upon volume of samples across a national programme and individual cost of cartridges.
Figure 4.
Cost-per-result based on number of samples run per day for Tiers 1 and 2 (line graphs), compared to published POC data [14] (actual reported points as light yellow bar graphs with extrapolated curve) versus baseline cost-per-result for Tier-3 (pale blue dotted line). The ‘+’ at the end of line represents higher capacity of workload of Tier-3 services.