An integrated tiered service delivery model (ITSDM) based on local CD4 testing demands can improve turn-around times and save costs whilst ensuring accessible and scalable CD4 services across a national programme

Abstract

Background: The South African National Health Laboratory Service (NHLS) responded to HIV treatment initiatives with two-tiered CD4 laboratory services in 2004. Increasing programmatic burden, as more patients access anti-retroviral therapy (ART), has demanded extending CD4 services to meet increasing clinical needs. The aim of this study was to review existing services and develop a service-model that integrated laboratory-based and point-of-care testing (POCT), to extend national coverage, improve local turn-around/(TAT) and contain programmatic costs.

Methods: NHLS Corporate Data Warehouse CD4 data, from 60-70 laboratories and 4756 referring health facilities was reviewed for referral laboratory workload, respective referring facility volumes and related TAT, from 2009-2012.

Results: An integrated tiered service delivery model (ITSDM) is proposed. Tier-1/POCT delivers CD4 testing at single health-clinics providing ART in hard-to-reach areas (<5 samples/day). Laboratory-based testing is extended with Tier-2/POC-Hubs (processing ≤ 30-40 CD4 samples/day), consolidating POCT across 8-10 health-clinics with other HIV-related testing and Tier-3/'community' laboratories, serving ≤ 40 health-clinics, processing ≤ 150 samples/day. Existing Tier-4/'regional' laboratories serve ≤ 100 facilities and process <350 samples/day; Tier-5 are high-volume 'metro'/centralized laboratories (>350-1500 tests/day, serving ≥ 200 health-clinics). Tier-6 provides national support for standardisation, harmonization and quality across the organization.

Conclusion: The ITSDM offers improved local TAT by extending CD4 services into rural/remote areas with new Tier-3 or Tier-2/POC-Hub services installed in existing community laboratories, most with developed infrastructure. The advantage of lower laboratory CD4 costs and use of existing infrastructure enables subsidization of delivery of more expensive POC services, into hard-to-reach districts without reasonable access to a local CD4 laboratory. Full ITSDM implementation across 5 service tiers (as opposed to widespread implementation of POC testing to extend service) can facilitate sustainable 'full service coverage' across South Africa, and save>than R125 million in HIV/AIDS programmatic costs. ITSDM hierarchical parental-support also assures laboratory/POC management, equipment maintenance, quality control and on-going training between tiers.

Figure 1. Geographical location of health and laboratory facilities in South Africa.

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 Table 1).

Figure 2. Colour-graded map indicating CD4 test volumes and laboratory-to-result turn-around-time (LTR TAT) in South Africa.

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).

Figure 3. Current CD4 service coverage precincts.

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 Fig. 2). 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.

Figure 4. Six-tiered CD4 service framework and ideal proposed service coverage.

4a 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. 4b 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.