HIV-positive individuals co-infected with hepatitis C virus are hospitalised longer, visit emergency departments more often and spend more days disabled than people with HIV alone, according to new data presented on Tuesday at the Sixteenth Conference on Retroviruses and Opportunistic Infections in Montreal, Canada.
An estimated 15% to 30% of HIV positive people also have chronic hepatitis C - though rates as high as 90% have been seen in some groups of injecting drug users. But the burden of disease and utilisation of health care by co-infected patients has not been well studied.
In this analysis, investigators compared hospitalisation, emergency department visits and disability amongst HIV-positive individuals with and without hepatitis C.
The researchers collected data from participants in the ACTG Longitudinal Linked Randomized Trials (ALLRT, also known as ACTG A5001) cohort, comprising treatment-naive and treatment-experienced HIV-infected individuals enrolled in selected randomised clinical trials of antiretroviral therapy sponsored by the US AIDS Clinical Trials Group.
Each year, participants provided information about their use of health services during the previous four months, including number of nights in hospital, number of visits to an emergency department and two measures of disability: number of days spent in bed and number of days forced to cut back on work or other daily activities. Reasons for hospitalisation were not collected. Disability could not be attributed to interferon-based therapy for hepatitis C, since very few patients received such treatment.
The analysis included 3082 HIV positive patients, who collectively contributed just over 81,000 person-months of follow-up data, with a median follow-up period of 28 months per person. A total of 359 patients (12% of the cohort) were co-infected with HIV and hepatitis C.
Compared with participants who had HIV alone, the co-infected patients were slightly older (average 40 vs 43 years), more often women (16% vs 21%), more often of "non-white" race/ethnicity (48% vs 63%) and much more likely to be current or former injecting drug users (4% vs 50%).
Both groups had about the same median CD4 count (approximately 245 cells/mm3) and median HIV viral load (40,000 copies/ml). To determine the effect of immune function, participants were divided into four CD4 cell strata.
The researchers found that HIV/hepatitis C co-infected patients at all CD4 counts spent more time in hospital than those with HIV alone: 99 vs 54 hospital nights per 100 person-years if they had fewer than 100 cells/mm3, 33 vs 16 nights if they had 100 to 200 cells/mm3, 15 vs 5.2 nights if they had 201 to 350 cells/mm3, and 2.5 vs 2.6 nights if they had more than 350 cells/mm3.
A similar pattern was seen for emergency department visits: 18 vs 17 visits per 100 person-years for patients with less than 100 cells/mm3, 12 vs 6.3 visits for those with 100 to 200 cells/mm3, 13 vs 3.7 visits for those with 201 to 350 cells/mm3, and 2.5 vs 2.6 visits for those with more than 350 cells/mm3.
Co-infected participants also fared worse than those with HIV alone when looking at days of disability: 481 vs 253 days per 100 person-years if they had less than 100 cells/mm3, 139 vs 104 days if they had 100 to 200 cells/mm3, 79 vs 66 days if they had 201 to 350 cells/mm3, and 57 vs 46 days if they had more than 350 cells/mm3.
After adjusting for possible confounding factors including age, sex, race, history of injection drug use, opportunistic infections, current CD4 cell count and HIV viral load, the researchers found that HIV/hepatitis C co-infection remained a significant predictor of longer hospitalisation (relative risk [RR] 1.9), more frequent emergency department visits (RR 1.7) and more disability days (RR 1.4).
These findings led the researchers to conclude that HIV/hepatitis C co-infected patients "have significantly increased rates of health care utilization and disability days, generating substantial additional burdens on the system of care for HIV-infected patients in the United States."