# Thirty-Day Readmissions After Hospitalization for Psoriatic Arthritis

## TL;DR

This study finds that nearly one-third of hospitalizations for psoriatic arthritis lead to readmission within 30 days, with factors like age and comorbidities playing a role.

## Contribution

The study identifies specific predictors and common causes of 30-day readmissions for psoriatic arthritis patients in the U.S.

## Key findings

- 29% of PsA hospitalizations resulted in 30-day readmissions, primarily due to acute kidney failure, major depression, and heart failure.
- Readmitted patients were younger, more often uninsured, and had higher hospital costs and longer stays than those with index admissions.
- Age under 40, home healthcare discharge, and secondary diagnoses of inflammatory bowel disease or deep venous thrombosis increased readmission risk.

## Abstract

Background

Psoriatic arthritis (PsA) is correlated with higher rates of major adverse cardiovascular events and autoimmune disorders than the general population, leading to more frequent hospitalizations. This study assessed the rates and characteristics of index and 30-day readmissions among adults hospitalized for PsA and evaluated the indications and predictors of 30-day readmissions across the United States.

Methodology

We analyzed the 2020 Nationwide Readmissions Database for adult PsA hospitalizations using the International Classification of Diseases, Tenth Revision, Clinical Modification codes. To compare baseline characteristics between index admissions and readmissions, we used chi-square tests. We used ranking commands to identify the most common indications for readmissions and multivariable Cox regression analysis to identify the predictors of readmissions. The primary endpoints were the rates and characteristics of index and 30-day readmissions. The secondary endpoint was the predictors of readmission within 30 days of index hospital discharge.

Results

Approximately 842 index hospitalizations for PsA were analyzed. Of these, 244 (29%) resulted in 30-day readmissions, with the primary causes being acute kidney failure, major depression, and heart failure. Readmitted patients had a mean age of 48.2 years (SD = 6.4 years) compared with 54.6 years (SD = 2.2 years) in index hospitalizations (p = 0.147). More readmitted patients were uninsured than index hospitalizations (18.6% vs. 4.4%; p = 0.015). The mean length of stay for readmissions was 7.2 days compared with 3.9 days for index admissions. The mean total hospital costs were US$31,424 for index admissions and US$60,147 for readmissions (p < 0.001). Significant differences in comorbidities such as hypertension (24.8% vs. 40.1%, p = 0.032), liver disease (29% vs. 7.9%, p = 0.020), uveitis (9.4% vs. 4.5%, p < 0.001), inflammatory bowel disease (8.6% vs. 3.8%, p < 0.001), and alcohol use disorder (29% vs. 7.8%, p = 0.002) were observed between readmissions and index admissions. Age <40 years (adjusted hazard ratio (AHR) = 2.35; p = 0.047), home healthcare (AHR = 5.87; p = 0.035), residence in the same state as the hospital (AHR = 1.24; p = 0.018), and secondary diagnoses of inflammatory bowel disease (AHR = 2.33; p < 0.001) or deep venous thrombosis (AHR = 3.80; p = 0.007) were correlated with an increased likelihood of readmission.

Conclusions

About one in three hospitalizations for PsA result in readmission within 30 days of initial discharge. Age <40 years, discharge to home healthcare, and a secondary diagnosis of inflammatory bowel disease or deep venous thrombosis were correlated with an increased likelihood of readmission.