The Prevalence of Clostridium difficile Colitis and Effect on All-Cause Mortality in Elderly Patients after Hip Fracture Surgery: A Korean Nationwide Cohort Study

BACKGROUND: This study aimed to investigate the prevalence of Clostridium difficile colitis (CDC) in elderly patients with hip fractures using a nationwide cohort database and to analyze the effect of CDC on the all-cause mortality rate after hip fracture. METHODS: This retrospective nationwide study identified subjects from the Korean National Health Insurance Service-Senior cohort. The subjects of this study were patients who were over 65 years old and underwent surgical treatment for hip fractures from January 1, 2002, to December 31, 2015. The total number of patients included in this study was 10,158. The diagnostic code used in this study was A047 of the International Classification of Diseases, 10th revision for identifying CDC. Procedure codes for C. difficile culture or toxin assay were BY021 and BY022. CDC patients were defined as follows: patients treated with oral vancomycin or metronidazole over 10 days and patients with procedure codes BY021 and BY022 or diagnostic code A047 after hip fracture. Incidence date (index date, time zero) of hip fracture for analyzing risk of all-cause mortality was defined as the date of discharge. A generalized estimating equation model with Poisson distribution and logarithmic link function was used for estimating adjusted risk ratios and 95% confidence intervals to assess the association between CDC and cumulative mortality risk. RESULTS: The prevalence of CDC during the hospitalization period in the elderly patients with hip fractures was 1.43%. Compared to the non-CDC group, the CDC group had a 2.57-fold risk of 30-day mortality after discharge, and a 1.50-fold risk of 1-year mortality after discharge (p < 0.05). CONCLUSIONS: The prevalence of CDC after hip fracture surgery in elderly patients was 1.43%. CDC after hip fracture in the elderly patients significantly increased the all-cause mortality rate after discharge.