496   Achievement and Durability of Viral Suppression in Patients Prescribed HAART in HIV Clinics in New York City.

J. Sackoff*¹, S. Shin¹, and J. Weedon².
¹New York City Dept. of Hlth., NY and²State Univ. of New York at Downstate, Brooklyn.

Background:Our objective was to evaluate the achievement and durability of viral suppression in HIV-infected patients prescribed highly active antiretroviral therapy (HAART) in routine practice.

Methods:The analysis draws on medical record data from the Adult Spectrum of HIV Disease study. The analytic sample comprised 318 patients with a detectable viral load (VL) (>400 copies/mL), and one or more subsequent VL tests, who were prescribed HAART between 1997 and 1999 in four HIV clinics in New York City. HAART was defined as three or more antiretrovirals including a protease inhibitor or a non-nucleoside reverse transcriptase inhibitor. Time to first undetectable VL (UNDET) and time to viral load rebound were analyzed using statistical methods for singly and doubly censored data.

Results:The 318 patients were 63% male and 93% black or Hispanic; the median age was 39 years and 29% had a history of injection drug use. At initiation of HAART, the median VL was 54,500 copies and the median CD4 count was 177 cells/mL. At six months post-HAART, 57% achieved a first UNDET, including 61% with baseline CD4 <200 cells and 57% with CD4 >200 cells (p>0.05) and 63% with baseline VL <60,000 copies and 52% with >60,000 copies (p>0.05). Patients who initiated HAART in 1997 took longer to achieve UNDET than patients who started in 1998/1999 (45% versus 65% at 6 months post-HAART, p<0.05), although the median VL was significantly lower in the 1997 cohort. Patients who achieved UNDET had a median increase of 101 CD4 cells [intraquartile range (IQR) = 154] at 6 months post-HAART, and patients who did not achieve UNDET had a median increase of 28 cells (IQR = 176). Among 203 patients who achieved UNDET, 162 had a subsequent VL test, and 73 rebounded. At 12 and 24 months post-UNDET, 54% and 34%, respectively, still had UNDET. Among the 73 who rebounded, the median viral load was 5,413 (IQR = 17,908).

Conclusions:Among HIV-infected patients receiving routine care, the majority of those who remained on HAART achieved UNDET, but only one-third maintained UNDET for two years. Since suppression over a prolonged period is feasible if treatment regimens are adhered to, initiatives to help clinic patients achieve this goal are necessary.