PMC

The effect on undiscounted life expectancy (solid line) and quality-adjusted life expectancy (dashed line) of identifying asymptomatic HIV infection, as compared with symptom-based case finding.

Each figure represents the incremental cost effectiveness of HIV screening (assuming traditional counseling) compared with current practice for patients of varying ages with differing underlying prevalence of unidentified HIV. The solid line represents an unidentified HIV prevalence of 0.1%, the black dashed line represents an HIV prevalence of 0.5%, and the grey line represents an HIV prevalence of 1%. In each figure the horizontal dashed lines indicate a cost effectiveness threshold of $50,000 and $100,000 per QALY. (a) Patients with a sexual partner at risk (b) Patients without a partner at risk. QALY = quality-adjusted life year, HIV = human immunodeficiency virus

The incremental cost effectiveness of HIV screening compared with current practice for patients of varying ages with differing underlying prevalence of unidentified HIV assuming implementation of streamlined counseling. The solid line represents an unidentified HIV prevalence of 0.1%, the black dashed line represents an HIV prevalence of 0.5%, and the grey line represents an HIV prevalence of 1%. The horizontal dashed lines indicate a cost effectiveness threshold of $50,000 and $100,000 per QALY or LY gained. (a) Patients with a sexual partner at risk (b) Patients without a partner at risk. QALY = quality-adjusted life year, LY = life year, HIV = human immunodeficiency virus

The square node at the left represents the decision to screen for HIV or not. The patient’s health thereafter is simulated by a Markov model shown on the right. Patients may enter the model with prevalent HIV infection (asymptomatic or symptomatic HIV or AIDS) or they may be uninfected. Each month, uninfected patients are at risk of developing HIV infection. Patients who have asymptomatic disease may progress to symptomatic HIV or remain in the asymptomatic health state. Patients that have symptomatic HIV infection may progress to an AIDS defining condition, or may remain with symptomatic HIV. Patients with AIDS may either die from their infection or remain with AIDS. Each month all patients may be identified either through a voluntary screening program in the HIV screen arm, or through symptom-based case finding in the symptomatic HIV and AIDS health states in both the HIV screen arm and the No Screening arm. Throughout the patients’ lifetime, all patients are at risk for non-HIV related mortality. Health states are further characterized by viral load level, CD4 count, and antiretroviral treatment history (not shown).