Purpose:
Methods:
We develop an individual-based Markov state transition model, Progression and Transmission of HIV/AIDS (PATH), to simulate HIV disease progression and treatment for 10,000 persons diagnosed in IP and ED settings. We use quarterly changes in CD4 count and viral RNA level to map disease progression. We additionally include published survival estimates based on the age of the patient and CD4 count at the initiation of antiretroviral therapy. We use program characteristics from each setting such as testing costs, median CD4 count at diagnosis, and prevalence of HIV infection, as well as the costs of treating HIV infection, to estimate the incremental cost per quality-adjusted life year (QALY) saved for a person diagnosed with HIV.
Results:
Diagnosing HIV infection in the ED versus IP setting led to an additional 2.3 QALYs at a cost of $16,549 per QALY. In sensitivity analysis, with an ED prevalence of 0.1%, the incremental cost-effectiveness ratio increased to $22,644 per QALY. Factors with the most effect on quality-adjusted life expectancy include age at infection, duration of antiretroviral therapy, and viral load set-point.
Conclusions:
Routine ED screening results in increased QALYs compared to IP testing and falls� within the standards of cost-effectiveness. Hospitals that have not already done so should consider routine HIV screening of persons in the ED.
Cost effectiveness analysis of testing in different settings*
Setting (Prevalence)
| CD4 count at diagnosis (cells/mL)
| Discounted costs1 ($)
| Discounted life expectancy1
| Discounted QALYs1
| Incremental Cost ($)
| Incremental QALY
| ICER ($/QALY)
|
IP �(14.6%)
| 24
| 245,498 (241,530-249,466)
| 16.3 (16.1-16.5)
| 14 (13.9-14.2)
|
|
|
|
ED (1%)
| 276
| 283,562 (280,108-287,015)
| 18.8 (18.7-19.0)
| 16.3 (16.1-16.4)
| 38,064
| 2.3
| 16,549
|
* 3% discount rate
1 Figures in parentheses are 95% confidence intervals
See more of: 30th Annual Meeting of the Society for Medical Decision Making (October 19-22, 2008)