495   Influence of Race and Economic Status on HIV Viral Load Trends Since Introduction of Protease Inhibitors and Combination Therapy.

H. Faruki*¹, F. Seillier-Moiseiwitsch², Y. Wu², T. Alcorn¹, and C. Van Der Horst².
¹LabCorp, Res. Triangle Park, NC and²Univ. of North Carolina at Chapel Hill.

Background:A serial monitoring database of 601,352 HIV viral load test results was analyzed to study viral load trends among US HIV patients since introduction of protease inhibitors.

Methods:The database included 286,873 individual patient files dating back to 1996, of which 41,536 had >4 test results. Using a 1990 US Census database of race and household income per zip code, viral load results were segregated into groups to examine the influence of race and economic status on the trends.

Results:The % patients with an undetectable viral load (<400 copies/mL) increased from 9% in 1st Qtr. 1996 to 44% by 4th Qtr 1999. Racial makeup of the area where the patient sought his/her care was significantly correlated with differences in the % of patients with undetectable viral load starting in 2nd Qtr l998 and continuing throughout 1999. Among patients from zip codes where Caucasians exceeded 60% of the population, rates of undetectable viral loads climbed to a high of 47% by 4th Qtr l999, whereas among those in areas where Caucasians comprised less than 25% of the population, only 33% had undetectable viral loads by 4th Qtr l999. Mean household income was also correlated with the % of patients with undetectable viral loads. Patients from areas where mean household income exceeded₄0,000/yr had an increase in % undetectable to 48% by 4th Qtr 1999, whereas among those from areas with the lowest mean income (<₁5,000), the percent patients with undetectable viral load never exceeded 32%. Differences in treatment failure rates, as measured by viral rebound to >10,000 copies/mL, were correlated with racial makeup but were not significantly correlated with mean household income.

Conclusions:Between 1st Qtr l996 and 4th Qtr 1999, the proportion of patients with undetectable viral loads rose from 9% to 44%. HIV patients from areas of the United States with a higher proportion of Caucasians, or with a higher median household income, were more likely to have an undetectable viral load.