Over 20 years, the total costs were $1,270 billion for normal screening, $1,272 billion for expanded screening, $1,276 billion for expanded screening and symptom-based viral load testing, and $1,283 billion for expanded screening and viral load testing (annual), plus symptom-based viral load testing. Testing made the largest contribution to costs (76 to 86%).
The total QALYs were 176.00 million for normal screening, 176.19 million for expanded screening, 176.32 million for expanded screening and symptom-based testing, and 176.39 million for expanded screening with viral load testing and symptom-based testing.
Compared with normal screening, the incremental cost per QALY gained was $12,582 for expanded screening, $20,013 for expanded screening and symptom-based testing, and $35,032 for expanded screening and annual testing plus symptom-based testing.
One-way sensitivity analyses showed that these results were stable to variations in most of the estimates, including potential over-testing from patients presenting with mild cold symptoms and modest increases in HIV-related deaths from early ART. The minimum HIV prevalence had to be 3% for symptom-based testing to remain below $50,000 per QALY.
The probabilistic sensitivity analysis showed that expanded screening was the preferred option at a willingness-to-pay (WTP) of less than $20,000 per QALY; expanded screening and symptom-based testing was preferred for thresholds between $20,000 and $80,000 per QALY; and expanded screening plus annual and symptom-based viral load testing was preferred for thresholds over $80,000 per QALY.