Abstract and Introduction
Abstract
Background Clostridium difficile colitis (CDC) is associated with an increased short-term mortality risk in hospitalised ulcerative colitis (UC) patients. We sought to determine whether CDC also impacts long-term risks of adverse health events in this population.
Aim To determine whether CDC also impacts long-term risks of adverse health events in this population.
Methods A population-based retrospective cohort study was conducted of UC patients hospitalised in Ontario, Canada between 2002 and 2008. Patients with and without CDC were compared on the rates of adverse health events. The primary outcomes were the 5-year adjusted risks of colectomy and death.
Results Among 181 patients with CDC and 1835 patients without CDC, the 5-year cumulative colectomy rates were 44% and 33% (P = 0.0052) and the 5-year cumulative mortality rates were 27% and 14% (P < 0.0001) respectively. CDC was associated with a higher adjusted 5-year risk of mortality [adjusted hazard ratio (aHR) 2.40, 95% CI 1.37–4.20], but not of colectomy (aHR 1.18, 95% CI 0.90–1.54). CDC impacted mortality risk both during index hospitalisation (adjusted odds ratio 8.90, 95% CI 2.80–28.3) as well as over 5 years following hospital discharge among patients who recovered from their acute illness (aHR 2.41, 95% CI 1.37–4.22). Colectomy risk was not influenced by CDC in this cohort.
Conclusion Clostridium difficile colitis is associated with increased short-term and long-term mortality risks among hospitalised ulcerative colitis patients. As colectomy risk is not similarly impacted by Clostridium difficile colitis, factors predictive of death among C. difficile-infected ulcerative colitis patients require elucidation.
Introduction
Clostridium difficile colitis (CDC) is the leading cause of nosocomial infectious diarrhoea and is associated with substantial morbidity and mortality. The past decade has witnessed a rise in the incidence and severity of CDC in hospitals across North America and Europe, largely attributable to the emergence of highly virulent strain of this organism.
Patients with ulcerative colitis (UC) are at increased risk of acquiring CDC. The incidence of CDC among UC patients has also been rising in recent years, with CDC now being implicated in up to 5% of UC hospital admissions. Nationwide studies have further reported that CDC is associated with a 3.8–5.5-fold higher acute mortality risk among hospitalised UC patients. The impact of CDC on acute colectomy risk in UC patients has been less consistent across studies.
In addition to increasing short-term health risks, CDC may pose sustained health risks to UC patients. Chronic C. difficile colonisation following an acute infectious episode may increase the risk of future CDC episodes in many patients. Moreover, the impact of CDC on UC disease behaviour remains unknown. One study reported that CDC was associated with a greater 1-year colectomy risk in these patients. However, no study has assessed the longer term impact of CDC on health outcomes in this population. As UC afflicts more than 500 000 individuals across North America, this could have significant implications for hospital care policy and health resource utilisation in these patients. Therefore, we sought to investigate the impact of CDC on 5-year health outcomes among hospitalised UC patients.