Deshpande A, et al. - By using a national readmission database, researchers sought to identify factors that predisposed patients to an increased risk of Clostridium difficile infection (CDI)-associated readmissions after an initial hospital discharge and the associated hospital costs. Data revealed a rising incidence of CDI-associated rehospitalizations compared with earlier results from the pre-epidemic era. Risk factors that predisposed patients to CDI-associated rehospitalizations included (as per univariable analysis) advanced age (>65 years) and the presence of several comorbid conditions and insurance coverage by Medicare and the presence of inflammatory bowel disease (IBD) and (as per multivariable regression analysis) insurance coverage by Medicare and the presence of IBD.

Methods

• For this study, researchers utililized the 2013 Nationwide Readmissions Database, Healthcare Cost and Utilization Project, Agency for Healthcare Research and Quality, designed to provide information on national readmission rates from 21 states and 2,006 hospitals in the United States.
• Adult patients aged ≥18 years were included in the study cohort.
• ICD-CM-9 code 00845 (primary and secondary diagnosis) was used to assess the initial occurrence of all hospitalizations involving CDI for the month of January 2013; these were designated as CDI-associated index admissions.
• All CDI-associated readmissions that occurred after a CDI-associated index admission in the period of January-December 2013 were searched.
• For this study, statistical tests included the X test, Mann-Whitney U test, and univariable and multivariable logistic regression analyses with generation of adjusted odds ratios (aORs) and 95% confidence intervals (CIs).
• They used SAS version 9.3 (SAS Institute, Cary, NC), and considered P values <.01 as the threshold for significance.

Results

• Researchers identified a total of 29,551 individual hospitalizations in January 2013 that carried a diagnosis of CDI.
• Of these, 2,787 (9.4%) patients died during hospitalization.
• In the surviving cohort, a subsequent CDI-associated hospitalization was not observed for 20,107 (68.0%) patients, whereas 6,652 (22.5%) patients experienced ≥1 CDI-associated readmissions during the study period.
• A total of 10,158 readmissions were observed in this group of 6,652 patients; 32.3% of these rehospitalizations carried a principal diagnosis of CDI.
• With readmission related to a principal diagnosis of CDI, the median cost associated was $8,000 (IQR, $8,000), and the median length of stay was 5 days (IQR, 5).
• When compared with their study counterparts who did not undergo a CDI-associated readmission, patients with CDI-associated readmissions significantly more frequently indicated a principal diagnosis of CDI (38.6% vs 32.3%, P < .001), were older (age >65 years: 65.3% vs 63.5%, P < .001), and were insured by Medicare (74.2% vs 68.7%, P < .001).
• Although the 2 groups were similar regarding the total number of comorbid conditions (median, 4; IQR, 3), patients with CDI-associated readmissions had a higher incidence of cardiac disease (25.7% vs 21.6%, P < .001), inflammatory bowel disease (IBD) (4.4% vs 3.7%, P < .001), renal failure (28.0% vs 24.2%, P < .001), diabetes mellitus (33.7% vs 29.6%, P < .001), and rheumatoid arthritis (6.0% vs 4.6%, P < .001).