POPULATION AND INDIVIDUAL COSTS OF HIV SERVICE PROVISION: THE IMPACT OF HAART 1996-1999

EJ Beck^1,2, S Mandalia², D Parmar², A Miners², M Youle², B Gazzard², M Fisher³, J Innes³, M Johnson³, G Kinghorn³, A Pozniak³, A Tang³, I Williams³ for the NPMS-HHC Steering Group
¹McGill University; ²NPMS-HHC Coordinating and Analysis Centre, Chelsea and Westminster Hospital, London, United Kingdom; ³NPMS-HHC Sites, England

Objective: To describe the impact of HAART on individual and population cost of HIV service provision in England.
Method: Data were collected from 7 NPMS-HHC sites. The NPMS-HHC monitors prospectively the cost-effectiveness of HIV service provision in England. Weighted mean per-patient-year (wPPY) indices of service use and cost were calculated by stage of HIV infection (CDSC classification) per semester from 1^st January 1996-31^st December 1999 and annual population costs for 1996-1999.
Results: Of 9931 patients, 84% were men. Increased prescribing of HAART coincided with a reduction of mono- or dual antiretroviral therapy. OIs decreased from a mean 363.1 events per 1000 patient-years (95% CIs 334.8 to 393.1) in the first semester of 1996 to 185.2 (95% CIs 161.9 to 211.0) in the second semester of 1999. Mean inpatient days for AIDS patients decreased from 11.8 (95%CI 10.3-13.3) to 7.5 (6.58 to 8.32) wPPY. Estimated costs of treating individual AIDS patients decreased from Can$55,374 ($43,958-$71,027) to Can$51,179 ($39,763-$66,832) or from Can$67,472 ($56,056-$83,125) to Can$61,076 ($51,861-$78,929) wPPY depending on HAART regimes used. Significant inverse correlations were observed between uptake of HAART and new OIs or the annual cost of individual AIDS patients. Direct population costs in 1996 varied between Can$460m ($387m-$557m) and Can$596m ($524m-$693m) depending on regimens, to between Can$585m ($497m-$706m) and Can$768m ($678m-$889m) respectively for 1999.
Conclusion: Increased uptake of HAART, reduced the incidence of AIDS defining opportunistic illnesses and the costs of HIV service provision. By reducing HIV associated morbidity and mortality, HAART has reduced the requirement for inpatient services and reduced the cost of treating people with AIDS. Increasing number of people alive with HIV infection will, however, increase the population costs for HIV treatment and care.