Validation of a clinical prediction scale for hospital-onset Clostridium difficile infection.

OBJECTIVE: The aim of this study was to validate a clinical prediction scale for hospital-onset Clostridium difficile infection (CDI). METHODS: The study included a consecutive cohort of patients admitted to the adult medical service over a period of 17 months (June 2011 to October 2012). The clinical prediction scale comprised of new-onset loose stools (5 points), length of hospital stay >7days (4 points), aged 65 years or older (3 points), resides in long-term care facility (2 points), broad spectrum antibiotics use (1 point), and hypoalbuminemia (1 point). The hospital-onset CDI cases were defined as any new-onset diarrhea after 48 hours of hospital admission that tested positive on polymerase chain reaction assay for C. difficile toxin gene in the absence of history of CDI in the prior 8 weeks. The predictive performance of the scale was assessed using area under the receiver operating curve. RESULTS: A total of 10,357 patients were admitted to the medical service, of which, 7026 stayed in hospital beyond 48 hours. Mean (SD) age was 68.5 (18.2) years and 41.9% patients were male. A total of 1030 patients were tested for C. difficile toxin gene using polymerase chain reaction assay, of which, 159 patients were positive and 62 of them were unique hospital-onset CDI cases. The scale had area under the receiver operating curve of 0.94 [95% confidence interval (CI), 0.92-0.95]. At the cutoff score of 9, scale was 98.3% (95% CI, 90.2-99.9) sensitive and 85.2% (95% CI, 84.3-86.0) specific. CONCLUSIONS: Our study results support excellent predictive performance of a clinical prediction scale for hospital-onset CDI. This simple scale can be used in risk stratification leading to prompt tailoring of modifiable risk factors, empirical treatment, and use of probiotics.