Purpose: Our objective was to estimate the cumulative clinical benefit of AIDS-related opportunistic infection prophylaxis and antiretroviral therapy (ART) in the US.

Methods: We used published estimates of the number of newly-diagnosed adult AIDS patients (mean CD4  87/mm³) receiving care in the US from l989-2003.  We considered six treatment eras, corresponding to advances in HIV care. Prevention of opportunistic infections was divided into two eras, one reflecting prophylaxis for Pneumocystis jiroveci pneumonia (PCP, 1989) and the other the addition of prophylaxis for Mycobacterium avium complex (MAC, 1993).   Treatment with combination ART was divided into four eras (ART 1-4) reflecting improvements in efficacy, decreases in regimen complexity and development of novel agents.  Per person survival benefits for each treatment were estimated using the Cost-effectiveness of Preventing AIDS Complications (CEPAC) model, a widely-published computer simulation model of HIV disease.  We also considered two additional treatment eras reflecting advances in the prevention of mother-to-child transmission, first with zidovudine alone and then with combination ART.  Sensitivity analyses evaluated the impact of earlier presentation to care.

Results:

Year	Intervention	# Pts in care	Per person survival gain (mo.)†	Total survival gains (yr.)
1989-1992	PCP	158,370	2.9	38,273
1993-1996	PCP/MAC	226,458	20.8	392,527
1997-1998	PCP/MAC/ ART-1	72,716	88.1	533,857
1998-1999	PCP/MAC/ ART-2	52,702	131.0	575,330
2000-2002	PCP/MAC/ ART-3	71,946	137.2	822,583
2003	PCP/MAC/ ART-4	24,780	158.3	326,890
		# infections averted
1994-1999	pMTCT	1,056	45.8-60.5 yrs.‡	51,646
2000-2003	pMTCT	1,829	46.7 yrs.	85,352
Total				2,826,458

                 

†Per person survival gains (in months) associated with prostate cancer therapy=1-11; breast cancer therapy=3.6-11; thrombolytics during myocardial infarction=15; and CABG=1-14 (Wright, et al. NEJM 1998)

‡Range in per person survival reflects changes in efficacy of treatment of an infected child over time.

Median survival was 1.7 years for the PCP era, 6.7 for ART 1, and 13.8 for ART 4.  As a surrogate for earlier presentation to care, we also examined a healthier cohort (mean CD4 175/mm³); cumulative survival benefits in this scenario increased to 3.3 million years. 

Conclusions: Progress in HIV therapy has saved over 2.8 million years of life in the US since 1989.  Per person benefits of ART exceed those conferred by treatment of other diseases and highlight the importance of expanded HIV diagnosis, linkage to care, and continued funding of HIV-related research.