Trends in Hospitalizations Among HIV-Infected Persons in the HAART Era
Trends in Hospitalizations Among HIV-Infected Persons in the HAART Era
Background: Declining rates of hospitalizations occurred shortly after the availability of highly active antiretroviral therapy (HAART). However, trends in the late HAART era are less defined, and data on the impact of CD4 counts and HAART use on hospitalizations are needed.
Methods: We evaluated hospitalization rates from 1999 to 2007 among HIV-infected persons enrolled in a large US military cohort. Poisson regression was used to compare hospitalization rates per year and to examine factors associated with hospitalization.
Results: Of the 2429 participants, 822 (34%) were hospitalized at least once with 1770 separate hospital admissions. The rate of hospitalizations (137 per 1000 person-years) was constant over the study period [relative rate (RR) 1.00 per year change, 95% confidence interval: 0.98 to 1.02]. The hospitalization rates due to skin infections (RR: 1.50, P = 0.02), methicillin-resistant staphylococcus aureus (RR: 3.19, P = 0.03), liver disease (RR: 1.71, P = 0.04), and surgery (RR: 1.17, P = 0.04) significantly increased over time, whereas psychological causes (RR: 0.60, P < 0.01) and trauma (RR: 0.54, P < 0.01) decreased. In the multivariate model, higher nadir CD4 (RR: 0.92 per 50 cells, P < 0.01) and higher proximal CD4 counts (RR of 0.71 for 350–499 vs. <350 cells/mm and RR 0.67 for ≥500 vs. <350 cells/mm, both P < 0.01) were associated with lower risk of hospitalization. Risk of hospitalization was constant for proximal CD4 levels above 350 (RR: 0.94 P = 0.51, CD4 ≥500 vs. 350–499). HAART was associated with a reduced risk of hospitalization among those with a CD4 <350 (RR: 0.72, P = 0.02) but had smaller estimated and nonsignificant effects at higher CD4 levels (RR: 0.81, P = 0.33 and 1.06, P = 0.71 for CD4 350–499 and ≥500, respectively).
Conclusions: Hospitalizations continue to occur at high rates among HIV-infected persons with increasing rates for skin infections, methicillin-resistant staphylococcus aureus, liver disease, and surgeries. Factors associated with a reduced risk of hospitalization include CD4 counts >350 cells per cubic millimeter and HAART use among patients with a CD4 count <350 cells per cubic millimeter.
Declining rates of hospitalizations occurred shortly after the availability of highly active antiretroviral therapy (HAART) along with significant reductions in both the length of stay and hospital mortality rates. These dramatic shifts were largely attributed to the effects of HAART, which decreased the incidence of AIDS events and improved the immune status of HIV-infected persons. Trends in hospitalization rates during the late HAART era are less defined, with some studies suggesting stabilization or increasing rates of hospitalizations. The potential reasons for the lack of continued decline in hospitalization rates include aging of the HIV population, development of chronic end-organ diseases, toxicity from long-term antiretroviral (ARV) use, development of multidrug-resistant viruses, and high prevalence of lifestyle-related factors such as illicit drug use and smoking.
As HIV-infected persons are surviving and experiencing longer life expectancies, hospitalizations have become an important outcome measure and are an important component of excess health care costs among this population. Hence, data on the rates of hospitalizations in the late HAART era are useful for both health care planning and the development of strategies to improve the health of HIV patients. Although higher CD4 counts and HAART use are known to decrease AIDS-defining events and death, their impact on hospitalizations is less certain, especially because many hospitalizations are now due to non-AIDS-defining comorbidities. Further investigation into the effects of treatment approaches on hospitalization rates are needed.
We evaluated prospectively collected data from an observational HIV Natural History Study (NHS) to investigate the trends and causes of hospitalizations among HIV-infected persons during the late HAART era. In addition, we assessed the impact of time-updated CD4 cell counts and ARV medication use on hospitalization events during the late HAART era.
Abstract and Introduction
Abstract
Background: Declining rates of hospitalizations occurred shortly after the availability of highly active antiretroviral therapy (HAART). However, trends in the late HAART era are less defined, and data on the impact of CD4 counts and HAART use on hospitalizations are needed.
Methods: We evaluated hospitalization rates from 1999 to 2007 among HIV-infected persons enrolled in a large US military cohort. Poisson regression was used to compare hospitalization rates per year and to examine factors associated with hospitalization.
Results: Of the 2429 participants, 822 (34%) were hospitalized at least once with 1770 separate hospital admissions. The rate of hospitalizations (137 per 1000 person-years) was constant over the study period [relative rate (RR) 1.00 per year change, 95% confidence interval: 0.98 to 1.02]. The hospitalization rates due to skin infections (RR: 1.50, P = 0.02), methicillin-resistant staphylococcus aureus (RR: 3.19, P = 0.03), liver disease (RR: 1.71, P = 0.04), and surgery (RR: 1.17, P = 0.04) significantly increased over time, whereas psychological causes (RR: 0.60, P < 0.01) and trauma (RR: 0.54, P < 0.01) decreased. In the multivariate model, higher nadir CD4 (RR: 0.92 per 50 cells, P < 0.01) and higher proximal CD4 counts (RR of 0.71 for 350–499 vs. <350 cells/mm and RR 0.67 for ≥500 vs. <350 cells/mm, both P < 0.01) were associated with lower risk of hospitalization. Risk of hospitalization was constant for proximal CD4 levels above 350 (RR: 0.94 P = 0.51, CD4 ≥500 vs. 350–499). HAART was associated with a reduced risk of hospitalization among those with a CD4 <350 (RR: 0.72, P = 0.02) but had smaller estimated and nonsignificant effects at higher CD4 levels (RR: 0.81, P = 0.33 and 1.06, P = 0.71 for CD4 350–499 and ≥500, respectively).
Conclusions: Hospitalizations continue to occur at high rates among HIV-infected persons with increasing rates for skin infections, methicillin-resistant staphylococcus aureus, liver disease, and surgeries. Factors associated with a reduced risk of hospitalization include CD4 counts >350 cells per cubic millimeter and HAART use among patients with a CD4 count <350 cells per cubic millimeter.
Background
Declining rates of hospitalizations occurred shortly after the availability of highly active antiretroviral therapy (HAART) along with significant reductions in both the length of stay and hospital mortality rates. These dramatic shifts were largely attributed to the effects of HAART, which decreased the incidence of AIDS events and improved the immune status of HIV-infected persons. Trends in hospitalization rates during the late HAART era are less defined, with some studies suggesting stabilization or increasing rates of hospitalizations. The potential reasons for the lack of continued decline in hospitalization rates include aging of the HIV population, development of chronic end-organ diseases, toxicity from long-term antiretroviral (ARV) use, development of multidrug-resistant viruses, and high prevalence of lifestyle-related factors such as illicit drug use and smoking.
As HIV-infected persons are surviving and experiencing longer life expectancies, hospitalizations have become an important outcome measure and are an important component of excess health care costs among this population. Hence, data on the rates of hospitalizations in the late HAART era are useful for both health care planning and the development of strategies to improve the health of HIV patients. Although higher CD4 counts and HAART use are known to decrease AIDS-defining events and death, their impact on hospitalizations is less certain, especially because many hospitalizations are now due to non-AIDS-defining comorbidities. Further investigation into the effects of treatment approaches on hospitalization rates are needed.
We evaluated prospectively collected data from an observational HIV Natural History Study (NHS) to investigate the trends and causes of hospitalizations among HIV-infected persons during the late HAART era. In addition, we assessed the impact of time-updated CD4 cell counts and ARV medication use on hospitalization events during the late HAART era.