Colour-graded map indicating CD4 test volumes and laboratory-to-result turn-around-time (LTR TAT) in South Africa.

<p>Map to reveal the daily CD4 test service volumes (workload), across 52 districts in South Africa, colour-graded according to volumes of tests requested, averaged over three year from 2009–2012. Higher testing volumes (as red or orange) as well as ‘hard to reach areas’ with low testing needs (yellow, more likely to require POC testing) are revealed. Approximately 3.8 million CD4 samples were referred during 2012 to an annual average of ∼60 designated NHLS CD4 facilities (existing shown as green dots). Insert reveals proportions of reports issued within a TAT of 48-hours, across all districts, averaged over years 2009–2012. The legend here highlights districts (as red) with less than 34% of reports or 35–80% of reports (mustard orange) issued within a 48-hour TAT (see legend on figure).</p

Relationship between CD4 tiers and NDOH Health Care Facilities.

<p>Table showing the integration of the category of Health Care Facility (NDOH ‘Classification of Health Care Facility’ <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0114727#pone.0114727-National8" target="_blank">[20]</a> offering ART) in relation to the proposed tier of CD4 service testing centre required to match and accommodate referred numbers of CD4 tests.</p><p>*testing facility framework and proportion offering ART; <b>^§</b>sample testing capacity per day.</p><p>Relationship between CD4 tiers and NDOH Health Care Facilities.</p

Current CD4 service coverage precincts.

<p>Map to reveal current estimated service precincts based on an averaged 100 km Euclidian radius. Areas without drawn service precincts largely coincide with districts with poorer LTR-TAT (see insert <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0114727#pone-0114727-g002" target="_blank">Fig. 2</a>). Note many health care facilities that fall outside of service precincts that would benefit from implementation of additional Tier-1, 2 and 3 services. Red circles highlight relatively over-subscribed areas with multiple ‘centralised’/metro laboratories in densely populated areas. In such metropolitan areas with high testing demands, amalgamation of services and the formation of a ‘super-laboratory’ could create critical mass, consolidate on technical skills and quality control provided that transport and IT logistics are absolutely optimized.</p

Geographical location of health and laboratory facilities in South Africa.

<p>Map to reveal geographic location of ∼4756 health facilities (as at 2011/2012); including primary care, community centers and hospital-based clinics (black dots) and 260 NHLS routine pathology service laboratories, across nine provinces and the related 52 districts. Insert reveals the proportions of different category of health facilities requesting CD4 testing (also see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0114727#pone-0114727-t001" target="_blank">Table 1</a>).</p

Six-tiered CD4 service framework and ideal proposed service coverage.

<p><b>4a</b> Graphical representation of an integrated, hierarchical ‘parent’, six-tiered CD4 service approach to secure scalable, ‘full-coverage’ across a national programme. From top to base, each band represents an increasing service load from an increasing base of referring health clinics. The proposed hierarchical ‘parent’ spatial support relationship between, and within, service tiers illustrates how higher service tiers can support and interact with lower service tiers, not only in a direct hierarchical fashion, but also how geographical location of different tiers in any given region can enable ‘parent/support’ relationships. <b>4b</b> Reveals existing and ideal proposed service coverage precincts of 5 tiers of service in South Africa, based on an averaged 50–100 km radius ‘coverage-precincts’. In both 4a and 4b, ‘A’ and ‘B’ reveal examples of the envisaged integrated support relationships between lower and upper tiers, specifically how a Tier-3 or Tier-4 level laboratory can supplement and support local Tier-1 and Tier-2 services respectively. Likewise, in addition to the proposed support infrastructure, ‘C’ also reveals how higher tiers can function together within a defined service precinct, to accommodate high service demands and provide infrastructure support in terms of service back-up and disaster recovery.</p

Description of Proposed CD4 Testing Tiers.

<p>Table outlining proposals for CD4 tiers, indicating number of sites, volumes (workload) per day and per annum, the number of clinics serviced, proposed platforms/instruments for testing and estimated costs.</p>§<p>Flow Cytometer systems with automated sample preparation systems accommodating testing volumes; <b>*</b>dependent upon organizational capacity planning and disaster recovery planning; <b>^§§</b>Assuming widespread POC services are used to supplement existing laboratory services (i.e. no extended laboratory services at Tier-2 lab-supported POC-HUBS or Tier-3 community laboratories). **ZAR/USD exchange of R11/USD1 as at November 3^rd, 2014. Abbreviations: BC, Beckman Coulter, USA. BD, BD Biosciences, USA. NA, not applicable.</p><p>Description of Proposed CD4 Testing Tiers.</p

CD4 tiers in Pixley-ka-Seme.

<p>ITSDM CD4 service for the Pixley-ka-Seme district includes Tiers 1–3 (proposed new tiers, which can be implemented in varying combinations to ensure ‘full service coverage’), and Tier-4 and Tier-5 (comprising existing service). Further breakdown of tier costs is included in the Results and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0115420#pone-0115420-g002" target="_blank">Fig. 2</a>.</p><p>* (Existing Pixley workload split between two existing higher tier laboratories, geographically closest to referring health-clinic site).</p>§<p>Total −$58 354. Abbreviations: BD, Becton Dickinson Biosciences. BC, Beckman Coulter International.</p><p>CD4 tiers in Pixley-ka-Seme.</p

Sensitivity analysis.

<p>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.</p

Costs per samples tested.

<p>Cost-per-result based on number of samples run per day for Tiers 1 and 2 (line graphs), compared to published POC data <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0115420#pone.0115420-Larson1" target="_blank">[14]</a> (actual reported points as light yellow bar graphs with extrapolated curve) versus baseline cost-per-result for Tier-3 (pale blue dotted line). The ‘<b>+</b>’ at the end of line represents higher capacity of workload of Tier-3 services.</p

Breakdown of costs.

<p>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.</p