Utilization of Rehabilitation Services After Idiopathic Inflammatory Myopathy (IIM) Diagnosis: A US Retrospective Cohort Assessment

Objective Investigate use 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 two IIM International Classification of Disease (ICD) codes between 1-12 months apart with at least a year of preceding data (from prior non-IIM ICD codes or Common 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 A total of 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 one PT, OT, and/or SLP evaluation over an average of 10 years follow up. Mean time to rehabilitation services utilization was just under 2 years after first IIM code. Older age and prior use of the respective rehabilitation service was associated with higher rehabilitation service use across all categories. The dermatomyositis ICD group had significantly lower PT and OT use compared to the polymyositis ICD group. Conclusion Rehabilitation use was infrequent overall, occurring nearly two years after the initial IIM ICD code. This may indicate barriers to appropriate integration of rehabilitation services for patients with IIM.