C. Difficile and Concomitant AKI Hospitalizations Increase, While Mortality Risk Declines

The mortality rate in C. difficile-infected patients with acute kidney infection is decreasing, from 23.9% to 14.8%, but hospitalizations increased significantly by 1.8 over the study period.

Paris Charilaou, MD

Between 2003 and 2012, there was a substantial rise in hospital admissions of patients with Clostridium difficile (C. difficile) infection and concomitant acute kidney injury (AKI).

Despite these findings, investigators of a recent study suggest that inpatient mortality among this patient population has decreased, possibly reflected by greater awareness, earlier identification, and improved care initiatives of AKI that have been implemented in the hospital setting.1

According to study investigator Paris Charilaou, MD, Chief Resident of the Saint Peter’s Healthcare System in New Brunswick, NJ, “AKI increases inpatient mortality by 86% compared with propensity-matched non-AKI patients with C. difficile infection (CDI), while the incidence of AKI itself is increasing among these patients.”

In their retrospective, observational study, investigators obtained patient data from the National Inpatient Sample database who were admitted to the hospital with C. difficile between the years 2003 and 2012. The investigators evaluated trends and infection-related complications as mortality predictive factors. In addition, the researchers estimated the independent effect of AKI on mortality through propensity-matching and by stratifying patients by chronic kidney disease status, in addition to adjusting for other baseline comorbidities.

Among the entire sample that presented with C. difficile infection (n= 2,859,599), approximately 31.3% (n= 896,122) demonstrated a principal diagnosis that led to hospital admission. The prevalence of AKI among this cohort was approximately 22%. In patients presenting with only C. difficile, the in-patient mortality rate was 8.4%. Comparatively, a greater proportion of patients with concomitant AKI had a higher mortality rate of 18.2%.

Following a multivariable regression analysis, the investigators found that the presence of AKI in addition to C. difficile infection was significantly associated with higher mortality (odds ratio [OR] = 3.16, 95% CI: 3.02-3.30; P <.001). The propensity-matching analysis demonstrated that AKI increased the risk for mortality by up to 86% (OR = 1.86, 95% CI: 1.79-1.94; P <.001). Although the incidence of hospitalizations related to C. difficile infections and concomitant AKI increased significantly by 1.8 over the study period (12.6% in 2003 to 28.8% in 2012, P-trend <.001), there was a significant decrease in overall mortality (9.0% in 2003 to 7.2% in 2012; P-trend <.001).

Independent of other comorbidities, AKI at hospital admission is a known major contributor to in-hospital mortality rates.2 When combined with C. difficile or any other serious, life-threatening infection, the risk for death likely increases.3 The early identification of AKI is perhaps the most significant factor in reducing death among patients, irrespective of their additional health issues (ie, C. difficile infection).4 Improved awareness and education regarding early detection of AKI have likely resulted in the decreased mortality rate observed in this study.

C. difficile infection with concomitant AKI should be treated according to the latest guidelines pertaining to severe C. difficile infection, using oral vancomycin, as we showed that the mortality rate in C. difficile-infected patients with AKI is decreasing, from 23.9% in 2003 to 14.8% in 2012," Charilaou concluded,


  1. Charilaou P, Devani K, John F, et al. Acute kidney injury impact on inpatient mortality in Clostridium difficile infection: A national propensity-matched study. [published online December 4, 2018]. J Gastroenterol Hepatol. doi: 10.1111/jgh.14064.
  2. Tang Y, Chen J, Huang K, et al. The incidence, risk factors and in-hospital mortality of acute kidney injury in patients after abdominal aortic aneurysm repair surgery. BMC Nephrol. 2017;18(1):184.
  3. Thongprayoon C, Cheungpasitporn W, Phatharacharukul P, Mahaparn P, Bruminhent J. High Mortality Risk in Chronic Kidney Disease and End Stage Kidney Disease Patients with Clostridium Difficile Infection: A Systematic Review and Meta-analysis. J Nat Sci. 2015;1(4).
  4. Selby NM, Hill R, Fluck RJ; for the NHS England 'Think Kidneys' AKI Programme. Standardizing the Early Identification of Acute Kidney Injury: The NHS England National Patient Safety Alert. Nephron. 2015;131(2):113-117.

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