Polymyositis/dermatomyositis readmissions: analysis of the nationwide readmission database.

Background: There is a scarcity of national population-based studies on polymyositis (PM)/dermatomyositis (DM) readmissions in the USA. In this study, we aim to describe the rates, reasons for readmissions, and characteristics of readmissions for adults hospitalized for PM/DM in the USA.

Methods: We analyzed the 2018 Nationwide Readmissions Database (NRD). We included index hospitalizations for all adult DM/PM patients with a principal diagnosis of PM/DM using ICD-10 codes. We excluded elective and traumatic readmissions. Using a "rank" command in STATA, the most common specific principal diagnosis of readmissions was outlined. Chi-square tests were used to compare baseline characteristics between readmissions and index hospitalizations. STATA 16 was used for analysis.

Results: A total of 1610, 1286, and 842 index hospitalizations with a principal diagnosis of PM/DM, that were discharged alive, were included in the 30-, 90-, and 180-day readmission analysis, respectively. Among these, 193 (12%), 276 (21.5%), and 240 (28.5%) were readmitted within 30, 90, and 180 days, respectively. PM and sepsis were the most common reasons for reasons across the 3 timeframes. 30-day readmissions were responsible for an aggregate of 4.1 million US dollars in total hospital cost and 1518 hospital days in 2018. Compared to index hospitalizations, 30-day readmissions have higher Charlson Comorbidity Index scores, severe-extreme loss of function, obesity, and deep venous thrombosis.

Conclusion: About a third of PM/DM hospitalized patients are readmitted within 180 days. Readmissions constitute a significant economic burden to the health care system. PM and sepsis are the main reasons for readmissions. Key points • About a third of polymyositis (PM)/dermatomyositis (DM) hospitalized patients are readmitted within 180 days • PM and sepsis are the main reasons for readmissions. • Readmissions of PM/DM Patients constitute a significant economic burden to the health care system. • Compared to index hospitalizations, 30-day readmissions have higher Charlson comorbidity index scores, severe-extreme loss of function, obesity, and deep venous thrombosis.