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

Objective: To identify baseline characteristics and treatment-related variables that impact 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. Interventions: OnabotulinumtoxinA at clinician's discretion. Main outcome measure(s): Clinically meaningful thresholds used for treatment adherent (≥3 treatment sessions during 2-year study) and non-adherent (≤2 sessions). Data analyzed using logistic regression and presented as odds ratios (OR) with 95% confidence intervals (CI). Treatment-related variables assessed at sessions 1 and 2 only. Results: Of the total population (N=730), 523 patients (71.6%) were treatment adherent with 5.3 (1.6; mean [SD]) sessions; 207 (28.4%) non-adherent with 1.5 (0.5). In the final model (n=626/730), 522 patients (83.4%) were treatment adherent, 104 (16.6%) were non-adherent. Baseline characteristics associated with adherence: treated in Europe (OR:1.84, CI:1.06-3.21; P=0.030) and use of orthotics (OR:1.88, CI:1.15-3.08; P=0.012). Baseline characteristics associated with non-adherence: history of diplopia (OR:0.28, CI:0.09-0.89; P=0.031) and use of assistive devices (OR:0.51, CI:0.29-0.90; P=0.021). Treatment-related variables associated with non-adherence: treatment interval ≥15 weeks (OR:0.43, CI:0.26-0.72; P=0.001) and clinician dissatisfaction with onabotulinumtoxinA to manage pain (OR:0.18, CI:0.05-0.69; P=0.012). Of the stroke population (N=411), 288 patients (70.1%) were treatment adherent with 5.3 (1.6; mean [SD]) sessions; 123 (29.9%) non-adherent with 1.5 (0.5). In the final stroke model (n=346/411), 288 patients (83.2%) were treatment adherent, 58 (16.8%) were non-adherent. Baseline characteristics associated with adherence: treated in Europe (OR:2.99, CI:1.39-6.44; P=0.005) and use of orthotics (OR:3.18, CI:1.57-6.45; P=0.001). Treatment-related variables associated with non-adherence: ...