US national estimation of emergency department utilization by patients given 'HIV/AIDS-related illness' as their primary diagnosis

Background: The emergency department (ED) is one of the most frequent sources of medical care for many HIV-infected individuals. However, the characteristics and ED utilization patterns of patients with HIV/AIDS-related illness as the primary ED diagnosis (HRIPD) are unknown. Methods: We identified the ED utilization patterns of HRIPD visits from a weighted sample of US ED visits (1993-2005) using the National Hospital Ambulatory Medical Care Survey, a nationally representative survey. Data on visits by patients≥18 years old were analysed using procedures for multiple-stage survey data. We compared the utilization patterns of HRIPD vs. non-HRIPD visits, and patterns across three periods (1993-1996, 1997-2000 and 2001-2005) to take into account changes in HIV epidemiology. Results: Overall, 492000 HRIPD visits were estimated to have occurred from 1993 to 2005, corresponding to 5-in-10000 ED visits. HRIPD visits experienced longer durations of stay (5.2h vs. 3.4h; P=0.001), received more diagnostic tests (5.1 vs. 3.3; P<0.001), were prescribed more medications (2.5 vs. 1.8; P<0.001) and were more frequently seen by physicians (99.5%vs. 93.8%; P<0.001) compared with non-HRIPD visits. HRIPD visits were more likely to result in admission [adjusted odds ratio (OR) 7.67; 95% confidence interval (CI) 5.14-11.44]. The proportion of HRIPD visits that required emergent/urgent care or were seen by attending physicians, and the number of diagnostic tests ordered, significantly increased over time (P<0.05), while the wait time (P=0.003) significantly decreased between the second and third study periods (P<0.05). Conclusions: Although HRIPD visits were infrequent relative to all ED visits, HRIPD visits utilized significantly more resources than non-HRIPD visits and the utilization also increased over time.