Validating Acute Kidney Injury as a Marker of Severity in Clostridium difficile Infection in Hospitalized Adults: Results from a Nation-wide survey: 2011 ACG Presidential Poster

Abstract

Purpose:Clostridium difficile infection (CDI) is known to cause adverse outcomes in hospitalized adults. Practice guidelines recommend that acute kidney injury (AKI), defined by an increase in serum creatinine ≥ 1.5 times baseline, is a marker of severe CDI based on consensus opinion. We examined clinical outcomes of hospitalized patients with CDI and AKI using the National Hospital Discharge Survey (NHDS) database. Methods: We analyzed NHDS data for 2005-2009; the database contains demographic information, ICD-9 diagnosis and procedure codes and discharge information for patients admitted to non-Federal United States hospitals with mean length of stay (LOS) < 30 days. CDI and AKI patients were identified using ICD-9 codes. 29 Comorbid conditions (hypertension, diabetes mellitus, heart failure, valvular disease, pulmonary circulation disorders, peripheral vascular disease, neurological disorders, malignancies, amongst others) were abstracted from the database using the Healthcare Cost and Utilization Project guidelines. Outcomes in patients with AKI and CDI were compared to patients with CDI without AKI using SAS version 9.2 and JMP version 9.0.1. Results: There were 9,911 hospitalized patients with CDI identified with median age 71 years and 59.9% were female. AKI developed during the hospitalization in 16.54%. On univariate analyses, CDI patients with AKI were significantly older (mean age 74.4 vs. 70.4 years, p<0.0001), had a higher risk of colectomy (2.2% vs. 1.2%, OR 1.87, 95% CI 1.27-2.75), and a higher all cause in-hospital mortality rate (17.4% vs. 5.7%, OR 3.52, 95% CI 3.0-4.1, p<0.001). CDI patients with AKI required longer length of stay (12.8 versus 10.2 days) and were more likely to be dismissed to a care facility (57.7% vs. 43.6%, OR 1.76, 95% CI 1.55-2.0) as compared to CDI patients without AKI (all p<0.001). After adjusting for age, gender and all comorbidities (except renal failure), AKI was an independent predictor of increased risk of colectomy (OR 1.66, p=0.01), higher all-cause in-hospital mortality (OR 2.78, p<0.0001), increased LOS (adjusted mean difference 1.2 days, p<0.0001), and dismissal to a care facility (OR 1.56, p<0.0001). Conclusion: AKI was associated with prolonged hospitalization, an increased likelihood of colectomy, and higher in-hospital mortality in hospitalized CDI patients. These findings support prior consensus opinion that AKI should be considered a marker of severe CDI and these patients should be managed more aggressively to prevent further adverse outcomes.