Utilization of Rehabilitation Services After Idiopathic Inflammatory Myopathy Diagnosis: A Retrospective Cohort Assessment in the United States

Abstract

Objective. To investigate utilization and timing of rehabilitation services for patients with idiopathic inflammatory myopathies (IIM). Methods. This was a retrospective analysis of US patients in the TriNetX dataset. Patients were defined by at least 2 IIM International Classification of Diseases, 9th/10th revision (ICD-9/10) codes between 1 and 12 months apart with at least 1 year of preceding data (from prior non-IIM ICD codes or Current Procedural Terminology [CPT] codes). Recurrent event modeling was performed from first IIM ICD code to the event of a CPT code for physical therapy (PT), occupational therapy (OT), and speech language pathology (SLP). Analysis was adjusted for the following potential confounders: age at first IIM ICD code, sex, IIM diagnosis subtype, stroke, hospitalization, orthopedic procedure, hip fracture, and glucocorticoid use. Results. In total, 22,434 patients with IIM and available data were identified, of whom 29.4% were male. After the first IIM ICD code, 20.1%, 5.3%, and 3.7% of patients had at least 1 PT, OT, and/or SLP evaluation, respectively, over an average of 10 years’ follow-up. Mean time to rehabilitation services use was just under 2 years after first IIM code. Older age and prior use of the respective rehabilitation service were associated with higher rehabilitation service use across all categories. The dermatomyositis ICD group had significantly lower PT and OT use compared with the polymyositis ICD group. Conclusion. Rehabilitation utilization was infrequent overall, occurring nearly 2 years after the initial IIM ICD code. This may indicate barriers to appropriate integration of rehabilitation services for patients with IIM.