POS0537 TRENDS AND PREDICTORS OF INPATIENT MORTALITY IN PATIENTS WITH CLOSTRIDIODES DIFFICILE INFECTION AMONG THOSE WITH AND WITHOUT RHEUMATOID ARTHRITIS: A NATIONWIDE ANALYSIS
Authors: M. Tahir, S. Alexander, R. Tariq, K. Wysham, J. Andrews, H. Aly, S. Khanna, N. Singh
Journal: Annals of the Rheumatic Diseases (2021)

Background: People with rheumatoid arthritis (RA) have a higher risk of serious infections. The most common nosocomial infection in the United States (US) is Clostridioides difficile infection (CDI) and yet, little is known regarding the impact of comorbid RA on outcomes in persons hospitalized with CDI. Objectives: To evaluate the trends over time and predictors of inpatient mortality in hospitalized patients with CDI comparing those with and without RA. Methods: We used the National Inpatient Sample (NIS) database, the largest available all-payer database of inpatient hospitalizations in the US. Patients aged ≥18 years admitted with CDI from 2006-2018 were included. Patients with RA were identified using the International Classification of Diseases (ICD) 9 and 10 codes. Categorical variables between CDI patients with and without RA were compared using Chi-squared test. Temporal trends of hospitalization charges, length of stay (LOS) and inpatient mortality were assessed using the Cochrane Armitage test. Predictors of inpatient mortality were assessed using multivariable logistic regression adjusting for: age ≥65, sex, race, presence of RA, and Elixhauser comorbidity index. Results: There were 4,396,945 hospitalizations with a discharge diagnosis of CDI in the study period, of which 111,336 (2.5%) had a coexisting diagnosis of RA. Over the study period, the proportion of CDI patients with a diagnosis of RA increased from 1.7% in 2006 to 3.3% in 2018 with a statistically significant trend of rise ( p trend&lt;0.001). There were significantly more females in the RA group (78.2%) than without RA (57.5%), p &lt;0.001. RA group was significantly younger (68.0 vs 70.7, P&lt;0.001). Races were similar between the groups. The inflation-adjusted average charge for hospitalization for CDI without RA was significantly higher than for CDI with RA ($95,863 vs $73,025, p&lt;0.001). There was an increasing trend in inflation-adjusted average charge for hospitalization for both CDI without RA ($76,966 in 2006 to $104,552 in 2018, p&lt;0.001) and CDI with RA ($55,689 in 2006 to $77,295 in 2018, p&lt;0.001). Patients with or without RA had the same median length of stay (LOS) of 7 days. But when trended over time, for patients without RA, the median LOS decreased from 8 days in 2006-08 to 6 days in 2016-18 whereas for patients with RA, the median LOS fluctuated between 6 and 7 days over the course of study period. CDI patients without RA had a significantly higher mortality over the study period than those with RA (7.8% vs 6.1%, p&lt;0.001). Among non-RA CDI patients, mortality decreased from 9.3% in 2006 to 6.3% in 2018 (p trend &lt;0.001). Hospitalizations of people with CDI and comorbid RA showed an overall decreasing trend (p trend &lt;0.001). The multivariable analyses found age≥65 was associated with increased inpatient mortality (adjusted odds ratio [aOR], 1.77, 95% confidence interval [CI], 1.73-1.80), whereas a diagnosis of RA was associated with a decreased mortality (aOR 0.86, 95% CI, 0.81-0.91) (Table 1). Table 1. Predictors of inpatient mortality aOR 95% C.I. for aOR P-value Lower Upper Age ≥ 65 1.765 1.730 1.801 &lt;0.001 Hospitalization years -Years 2006-2011 Ref -Years 2011-2014 0.707 0.693 0.721 &lt;0.001 -Years 2015-2018 0.582 0.569 0.594 &lt;0.001 Elixhauser Comorbidity Index 1.056 1.055 1.056 &lt;0.001 Rheumatoid Arthritis 0.859 0.810 0.911 &lt;0.001 Female 0.870 0.855 0.885 &lt;0.001 Race -White Ref -African American 1.071 1.044 1.099 &lt;0.001 -Hispanic 1.144 1.108 1.180 &lt;0.001 -Asian/Pacific Islander 1.267 1.200 1.337 &lt;0.001 -Native American 1.022 0.910 1.147 0.716 -Other races 1.263 1.201 1.329 &lt;0.001 aOR = Adjusted Odds Ratio; C.I.= confidence interval Conclusion: In this nationwide study, among hospitalized patients with CDI, those with comorbid RA had significantly decreased odds of inpatient mortality than those without RA. Further studies are needed to understand this association. Figure 1. Disclosure of Interests: None declared