HIV-HCV Coinfected Patients Experience Longer Hospitalization, More Emergency Visits, and Greater Disability than People with HIV Alone

By Liz Highleyman

As people with HIV live longer thanks to effective antiretroviral therapy, non-AIDS-defining illnesses have become major contributors to illness and death in the HIV positive population. Liver disease, in particularly, is more common in HIV patients coinfected with chronic viral hepatitis.

Given that an estimated 15%-30% of HIV positive people are coinfected with hepatitis C virus (HCV), Benjamin Linus and colleagues looked at healthcare utilization among HIV-HCV coinfected patients in the ACTG Longitudinal Linked Randomized Trials (ALLRT) cohort (ACTG A5001), which is conducting long-term follow-up of HIV positive participants enrolled in selected clinical trials of antiretroviral treatment. Results were presented last week at the 16th Conference on Retroviruses and Opportunistic Infections (CROI 2009) in Montreal.

Study participants provided annual self-reports of healthcare utilization during the prior 4-month period. The investigators used this information to calculate the number of nights spent in a hospital, emergency department (ED) visits, and disability days. Disability was calculated based on 2 measures, the number of days spent in bed and the number of days forced to cut back on work or daily activities.

To assess the effect of immune function, participants were divided into 4 CD4 count strata:

< 100 cells/mm3;
100-200 cells/mm3;
201-350 cells/mm3;
> 350 cells/mm3.

The analysis included 3082 HIV positive patients, of whom 359 (12%) also had HCV. Coinfected participants were on average older than those with HIV alone (43 vs 40 years), less likely to be men (79% vs 84%), more often non-white (63% vs 48%), and more likely to have a history of injection drug use (50% vs 4%). Both groups had a similar CD4 count (about 245 cells/mm3) and HIV viral load (roughly 40,000 copies/mL). ALLRT enrolled both antiretroviral naive and experienced patients.

The researchers controlled for potential confounding factors including age, sex, race, history of injection drug use, current CD4 cell count and HIV RNA level, and history of opportunistic infections. Most patients were not receiving interferon-based therapy for hepatitis C, so this factor did not influence disability rates.

Results

HIV-HCV coinfected patients at all CD4 count strata spent more time in a hospital than those with HIV monoinfection:

< 100 cells/mm3: 99.0 vs 54.0 nights per 100 person-years [PY], respectively;
100-200 cells/mm3: 33.0 vs 16.0 nights per 100 PY;
201-350 cells/mm3: 15.0 vs 5.2 nights per 100 PY;
o > 350 cells/mm3: 2.5 vs 2.6 nights per 100 PY.

Coinfected patients across the board also made more emergency department visits than HIV monoinfected patients:

< 100 cells/mm3: 18.0 vs 17.0 visits per 100 person-years [PY], respectively;
100-200 cells/mm3: 12.0 vs 6.3 visits per 100 PY;
201-350 cells/mm3: 13.0 vs 3.7 visits per 100 PY;
> 350 cells/mm3: 3.9 vs 2.1 visits per 100 PY.

Finally, coinfected participants had more days of disability than those with HIV alone:

< 100 cells/mm3: 481 vs 253 days per 100 person-years [PY], respectively;
100-200 cells/mm3: 139 vs 104 days per 100 PY;
201-350 cells/mm3: 79 vs 66 days per 100 PY;
> 350 cells/mm3: 57 vs 46 days per 100 PY.

After adjusting for potential confounding factors, HIV-HCV coinfection remained a significant predictor of worse healthcare outcomes:

Longer hospitalization: relative risk [RR] 1.9;
More emergency department visits: RR 1.7;
More disability days: RR 1.4.

For all 3 measures, the difference between the HIV-HCV coinfected vs HIV monoinfected groups was not statistically significant in the lowest CD4 cell strata, which the investigators suggested might be due to "competing risks" in severely immunocompromised patients.

Based on these findings, the researchers concluded, "HIV-HCV coinfection is associated with substantially increase utilization of hospital and ED resources compared to HIV monoinfection. HIV-HCV coinfection is also associated with significantly increased disability days."

In terms of policy implications, they said, "HIV programs serving a high proportion of HIV-HCV coinfected patients can expect 1.5 to 2 times higher rates of hospitalizations, ED visits, and disability days than would be expected from a similar population of HIV monoinfected patients."

2/17/09

Reference
B Linas, B Wang, M Smurzynski, and others. The effect of HCV co-infection on health care utilization among HIV-infected subjects: the ACTG longitudinal linked randomized trials, study 5001. 16th Conference on Retroviruses and Opportunistic Infections (CROI 2009). Montreal, Canada. February 8-11, 2009. Abstract 102.