Dr Yingxi Chen1, A/Prof Bette Liu2, A/Prof Kathryn Glass1, Prof Thomas Riley3, Dr Rosemary Korda1, A/Prof Martyn Kirk1
1Australian National University, Canberra, Australia,
2University of New South Wales, Sydney, Australia,
3Microbiology & Immunology, University of Western Australia, and Department of Microbiology Path West Laboratory Medicine, Queen Elizabeth II Medical Centre, Nedlands, Australia
Introduction: Clostridium difficile is the principal cause of infectious diarrhoea in hospitalised patients. We described the epidemiology of C. difficile-related hospitalisation, and compare length of stay (LOS), costs, and in-hospital deaths for CDI and non-CDI hospitalisations, in a cohort of middle-aged and older Australians.
Methods: We linked data from a population-based prospective cohort study (the 45 and Up Study) of over 266,000 adults aged ≥45 years to hospitalisation and death records for 2006-2012. We estimated the incidence of CDI hospitalisation and calculated days in hospital and costs per hospitalisation. We also estimated hazard ratios (HR) for CDI hospitalisation using Cox regression with age as the underlying time variable.
Results: Over a total follow-up of 1126708 person-years, 187 adults had an incident CDI hospitalisation. The crude incidence of CDI hospitalisation was 16.6 per 100,000 person-years, with a median hospital stay of 6 days, and a median cost of AUD$ 6102 per admission. Incidence increased with age and year of follow-up, with a 3-fold increase for 2009-2012. CDI hospitalisation rates were significantly lower in males than females (aHR 0.6, 95%CI 0.4-0.7). After adjusting for age and sex, hospitalisations with CDI were associated with longer LOS, higher costs and a greater proportion of in-hospital deaths compared to hospitalisations with a similar principal diagnosis but without CDI.
Conclusions: CDI hospitalisation rates increased significantly over 2009-2012, with CDI patients having relatively lengthy hospital stays and high costs. There is a need to better understand the increasing risk incidence of CDI hospitalisation among women.
A/Prof Martyn Kirk is an Associate Professor and Convenor of the Master of Philosophy in Applied Epidemiology (MAE) program offered by the National Centre for Epidemiology and Population Health in the Research School of Population Health at the Australian National University.