Real-World Adherence to OnabotulinumtoxinA Treatment for Spasticity: Insights From the ASPIRE Study

Objective: To identify baseline characteristics and treatment-related variables that affect adherence to onabotulinumtoxinA treatment from the Adult Spasticity International Registry (ASPIRE) study. Design: Prospective, observational registry (NCT01930786). Setting: International clinical sites. Participants: Adults with spasticity (N=730). Interventions: OnabotulinumtoxinA at clinician's discretion. Main Outcome Measures: Clinically meaningful thresholds used for treatment adherent (>= 3 treatment sessions during 2-year study) and nonadher-ent (<= 2 sessions). Data analyzed using logistic regression and presented as odds ratios (ORs) with 95% confidence intervals (CIs). Treatment-related variables assessed at sessions 1 and 2 only. Results: Of the total population, 523 patients (71.6%) were treatment adherent with 5.3 +/- 1.6 sessions and 207 (28.4%) were nonadherent with 1.5 +/- 0.5 sessions. In the final model (n=626/730), 522 patients (83.4%) were treatment adherent and 104 (16.6%) were nonadherent. Baseline characteristics associated with adherence: treated in Europe (OR=1.84; CI, 1.06-3.21; P=.030) and use of orthotics (OR=1.88; CI, 1.15-3.08; P=.012). Baseline characteristics associated with nonadherence: history of diplopia (OR=0.28; CI, 0.09-0.89; P=.031) and use of assistive devices (OR=0.51; CI, 0.29-0.90; P=.021). Treatment related variables associated with nonadherence: treatment interval >15 weeks (OR=0.43; CI, 0.26-0.72; P=.001) and clinician dissatisfaction with onabotulinumtoxinA to manage pain (OR=0.18; CI, 0.05-0.69; P=.012). Of the population with stroke (n=411), 288 patients (70.1%) were treatment adherent with 5.3 +/- 1.6 sessions and 123 (29.9%) were nonadherent with 1.5 +/- 0.5 session. In the final stroke model (n=346/411), 288 patients (83.2%) were treatment adherent and 58 (16.8%) were nonadherent. Baseline characteristics associated with adherence: treated in Europe (OR=2.99; CI, 1.39-6.44; P=.005) and use of orthotics (OR=3.18; CI, 1.57-6.45; P=.001). Treatment-related variables associated with nonadherence: treatment interval >15 weeks (OR=0.42; CI, 0.210.83; P=.013) and moderate/severe disability on upper limb Disability Assessment Scale pain subscale (OR=0.40; CI, 0.19-0.83; P=.015). Conclusions: These ASPIRE analyses demonstrate real-world patient and clinical variables that affect adherence to onabotulinumtoxinA and provide insights to help optimize management strategies to improve patient care. (C) 2021 The Authors. Published by Elsevier Inc. on behalf of The American Congress of Rehabilitation Medicine.