Ab0265 Frailty and Adverse Clinical Outcomes After Hospitalization in Patients With Idiopathic Inflammatory Myopathy: A Nationwide Us Study

Background: Previous studies from the US have reported a high rate of 6-month readmission after hospitalization in patients with idiopathic inflammatory myopathies (IIM), leading to a high burden on healthcare system [1]. Frailty has already been associated with worse outcomes in autoimmune diseases such as giant cell arteritis, lupus, and rheumatoid arthritis [2-4]. Objectives: To describe the association between frailty status and adverse clinical outcomes such as readmissions, mortality, and hospitalization burden, in hospitalized patients with IIM. Methods: We performed a retrospective study using the 2017 US National Readmission Database (NRD). The NRD is a population-wide longitudinal database developed by the Healthcare Cost and Utilization Project (HCUP). This database accounts for 49.3% of the US population and contains approximately 85% of discharges from the State Inpatient Databases. We identified adult patients with an ICD-10 code of primary or secondary diagnosis of IIM, hospitalized between January and June 2017, with at least a 6-month of follow-up. We characterized their frailty status using the Hospital Frailty Risk Score: patients with a score≥5 at index hospitalization were categorized as frail. We evaluated burden of hospitalization according to the frailty status: total days spent in hospital and annual costs, 6-month risk of readmissions, and mortality. We also investigated the main causes of readmissions. We used Cox proportional hazard models to estimate the association between frailty and total days of hospitalization, 6-month readmission rate, and mortality, after adjustments on relevant covariates (sex, age, income, Medicare/Medicaid status, associated interstitial lung disease, obesity). Results: We identified 908 patients who met the eligibility criteria, of whom 69% were female, with a median age of 60 [40-68] years. Among them, 43% were categorized as frail and 12% had an associated ICD-10 code of interstitial lung disease. Details are shown in Table 1. Frail patients were older (62 versus 56 years), with higher Medicare/Medicaid coverage (76% versus 60%). During the follow-up, frail patients experienced longer hospitalization (17 versus 11 days), with a higher overall cost ($188k versus $126 k), and more in-hospitalization deaths (9% versus 3%). The 6-month readmission rate was not different (42% versus 36%) between the two groups. In multivariable analysis, frailty was significantly associated with the total days of hospitalizations (2.99 [1.54-5.82]) and mortality (2.67 [1.35-5.60]). Of note, the main causes or 6-month readmissions in the whole group were infections, vascular diseases and IIM. Conclusion: Among hospitalized patients with IIM, frailty is an important prognosis factor, since it seems to drive the mortality and the total length of hospitalization among patients with IIM. A better identification of those patients at index hospitalization could help the physician to better adjust the management in these patients, in order to reduce incidence of those poor health outcomes. REFERENCES: [1] Idolor O, Edigin E, Hino C, He E, Rao J, Ugoh AC, et al. Polymyositis/dermatomyositis readmissions: analysis of the nationwide readmission database. Clin Rheumatol 2023;42:2833–2839. [2] Goulabchand R, Qian AS, Nguyen NH, Singh AG, Roubille C, Parreau S, et al. Burden, Causes and Outcomes of Hospitalization in Patients with Giant Cell Arteritis: A US National Cohort Study. Arthritis Care Res 2022. [3] Lieber SB, Nahid M, Legge A, Rajan M, Lipschultz RA, Lin M, et al. Comparison of two frailty definitions in women with systemic lupus erythematosus. Rheumatol Oxf Engl 2023:kead393. [4] Singh N, Gold LS, Lee J, Wysham KD, Andrews JS, Makris UE, et al. Frailty and risk of serious infections in patients with rheumatoid arthritis treated with biologic or targeted-synthetic DMARDs. Arthritis Care Res 2023. Table 1. Baseline characteristics of 908 idiopathic inflammatory myopathy inpatients, selected from 2017 US National Readmission Database. Acknowledgements: NIL. Disclosure of Interests: Radjiv Goulabchand Novartis, Roche-Chugai, Christopher Leung: None declared, Siddharth Singh Pfizer, Namrata Singh: None declared.