1. Point-of-care CD4 tests can increase life-years saved with reduced costs compared to flow cytometric CD4 counting C.L. Grundy 1, A. Medina Lara 2, D. Winogron 3, A.P. Croucher 3, H.-G. Batz 3, T.B. Hallett 1 and S.D. Reid 3 1 Imperial College London, London, United Kingdom, 2 Bocconi University, Milan, Italy, 3 Imperial College London, CD4 Initiative, London, United Kingdom

2. INTRODUCTION Initiating ART optimal with CD4 count – Large number start ART without benefit of CD4 Current WHO guidelines indicate starting ART at 350 cells/mm 3 – Not all countries follow this recommendation – Trend for higher CD4 counts in high-income countries Gold standard CD4 counting = flow cytometry (BD or Beckman) Flow cytometric CD4 counting not widespread in low-income countries – Infrastructure and costs for rural areas difficult to achieve

3. POINT-OF-CARE CD4 TESTS CD4 Initiative established in 2005 to develop rapid, economical, point-of-care tests for CD4. Aim to develop tests which require limited/no infrastructure – No electronics, simple to use, cheap, to initiate ART Start ART with CD4 count = better outcomes POC CD4 count = decentralised test May improve retention to care in ART programmes – Reduce time to ART – Reduce loss to follow up

4. POINT-OF-CARE CD4 TESTS New generation of point-of-care CD4 tests available – Alere’s PIMA already in use – Others coming in the next 12-24 months Zyomyx, Inc (from CD4 Initiative programme) Daktari

5. IMPACT OF POC CD4 TESTS Widespread introduction of POC CD4 tests is expected in next 12-24 months Impact of introduction is not obvious Before results of clinical trials, useful to address potential impact using mathematical modelling

6. AIMS To look at impact on Life Years Saved (LYS) of syndromic management and 2 CD4 counting strategies, flow cytometry and point-of-care CD4 tests, on a model of ART initiation Examine total costs associated with each strategy.

7. METHOD

8. MODEL Work presented here is based on a model of ART initiation of Hallett et al, 2008. Added in costs for CD4 counting technologies Represents diagnosis, disease progression, clinical monitoring and associated costs Varied fraction of women referred from ANC and those from VCT Hallett TB, Gregson S, Dube S, Garnett GP. The impact of monitoring HIV patients prior to treatment in resource-poor settings: insights from mathematical modelling. PLOS Med 2008: 5(3)

9. PARAMETERS Adjusted cost and loss-to-follow up parameters in model Used 2 different ART initiation thresholds – 250 and 350 Several different CD4 count costs recorded

10. CD4 COSTS 2 flow CD4 costs and 2 POC CD4 costs were calculated: – Costs of reagents/test price – Staffing/personnel needed to carry out the test – Infrastructure/laboratory costs (if needed) – Overhead for hospital/laboratory (if needed) – Based calculations on time & motion studies and on reported CD4 costs (Zimbabwe and Uganda) – Arrived at fully-loaded test price

11. CD4 COUNT COST MAKE UP

12. CD4 COSTS HIGHLOW CD4 Flow $16$11 CD4 POC $10$6 These are estimated costs based on these 2 different CD4 counting strategies

13. INITIATING ART WITH POC CD4 TESTS INCREASES LIFE-YEARS SAVED RESULTS

15. LIFE YEARS SAVED

16. IMPACT AND COSTS Costs/LYS Life years saved SYNDROMIC

17. COSTS AND COSTS/LYS LOW TEST COSTTOTAL COSTSCOSTS PER LYS SYNDROMIC FLOW CYTOMETRY POINT OF CARE $488,290 $828,810 $822,870 $154 $169 $153

18. CONCLUSIONS POC CD4 testing more effective than flow cytometry (70% versus 52% increase in life years saved) Flow cytometry tended to greatest overall costs POC CD4 similar costs/LYS to syndromic management POC CD4 testing costs could be a more cost- effective strategy.

19. NEXT STEPS Look at budget impact analysis on a macro level Refine LFU using more appropriate figures from programmatic data Modify costs as they emerge

20. ACKNOWLEDGEMENTS Funders: Bill & Melinda Gates Foundation BRC at Imperial College London The Monument Trust For helpful discussion and data: Prof Charlie Gilks (UNAIDS) Maureen Murtagh (formerly CHAI) Dr Graham Cooke (Imperial)