Objectives: To describe hospitalization rates, risk factors and associated diagnoses in people with HIV in Australia between 1999 and 2007.
Design: Retrospective cohort study of people with HIV (n = 842) using data linkage between the Australian HIV Observational Database and administrative hospital morbidity data collections.
Methods: Incidence rate ratios with 95% confidence intervals were estimated using Poisson regression models to assess risk factors for hospitalization. Predictors of length of stay were assessed using generalized mixed models. The association between hospitalization and mortality was assessed using Cox regression.
Results: In 4519 person-years of observation, there were 2667 hospital admissions; incidence rate of 59 per 100 person-years. Hospitalization rates were 50–300% higher in this cohort than comparable age and sex strata in the general population. Older age (incidence rate ratio 1.46, 95% confidence interval 1.28–1.65 per 10-year increase) and prior AIDS (incidence rate ratio 1.71, 95% confidence interval 1.24–2.35) were significantly associated with hospitalization. Other predictors of hospitalization included lower CD4 cell counts, higher HIV RNA, longer duration of HIV infection and experience with more drug classes. Lower CD4 cell counts, older age and hepatitis C virus antibody positivity were independently associated with longer hospital stay. Non-AIDS diseases were the principle reason for admission in the majority of cases. Mortality was associated with more frequent hospitalization during the study period.
Conclusion: Hospitalization rates are higher in people with HIV than the general population in Australia and are associated with markers of advanced HIV disease despite the widespread use of combination antiretroviral therapy.
aNational Centre in HIV Epidemiology and Clinical Research, Australia
bSchool of Public Health and Community Medicine, University of New South Wales, Sydney, New South Wales, Australia
cCentre for Clinical Immunology and Biomedical Statistics, Royal Perth Hospital and Murdoch University, Perth, Western Australia, Australia
dDepartment of Infectious Diseases and Hospital Epidemiology, The Alfred Hospital, Melbourne, Victoria, Australia
eNational Association of People Living with HIV/AIDS, Sydney, New South Wales, Australia.
Received 18 December, 2009
Revised 21 February, 2010
Accepted 3 March, 2010
Correspondence to Dr Kathleen Falster, Sax Institute, PO Box 123, Broadway, NSW 2007, Australia. Tel: +61 2 9514 5963; fax: +61 2 9514 5951; e-mail: firstname.lastname@example.org