Thirty-day hospital readmission in systemic sclerosis associated pulmonary hypertension: A nationwide study

Objective: To identify risk-factors for 30-day hospital readmission in systemic sclerosis pulmonary hypertension (SSc-PH) and to compare trends and characteristics of 30-day readmissions in SSc-PH versus non-SSc pulmonary arterial hypertension (non-SSc PAH).

Methods: In this retrospective study, we identified SSc-PH and non-SSc PAH hospitalizations using ICD-9 codes within the Healthcare Cost and Utilization Project-National Readmission Database. Thirty-day readmission rates were calculated between 2010 and 2015. Characteristics were compared using chi-square, Wilcoxon rank-sum, or two-sample t-tests between (A) SSc-PH patients with versus without readmission and (B) patients with ≥1 readmission with SSc-PH versus non-SSc PAH. Adjusted logistic regression models were generated for readmission in SSc-PH.

Results: 4,846 of 22,420 (22%) with SSc-PH and 10,573 of 49,254 (21%) with non-SSc PAH had ≥1 30-day readmission. Between 2010-2015, readmission rate decreased in non-SSc PAH (23% to 20%; p<0.001) and was unchanged in SSc-PH (23% to 23%; p = 0.77). In SSc-PH, independent predictors of 30-day readmission include male sex, age <60, Medicare or Medicaid, higher Charlson/Deyo comorbidity index, and congestive heart failure (CHF). A higher proportion of patients with SSc-PH (vs. non-SSc PAH) died during index hospitalizations (p = 0.001) and readmissions (p <0.001). Readmitted patients with SSc-PH (vs. non-SSc PAH) were younger and less often had CHF. In SSc-PH, the most common readmission primary diagnosis was infection, followed by respiratory and heart failure.

Conclusion: In SSc-PH, 30-day readmission is frequent, and in-hospital deaths occur at a higher rate compared to those with non-SSc PAH. This study identifies factors that may characterize those with SSc-PH at highest risk for readmission.