Minimal clinically important change in the Toronto Western Spasmodic Torticollis Rating Scale. (July 2018)

• Record Type: Journal Article
• Authors: Espay, Alberto J.; Trosch, Richard; Suarez, Gustavo; Johnson, Jonathan; Marchese, Dominic; Comella, Cynthia
• Is Part Of: Parkinsonism & related disorders. Volume 52(2018)
• Page Start: 94
• Page End: 97
• Publication Date: 2018-07
• Subjects: Cervical dystonia -- Toronto western spasmodic torticollis rating scale -- Minimal clinically important change -- Botulinum toxin -- abobotulinumtoxinA; Parkinson's disease -- Periodicals; Movement disorders -- Periodicals; Movement Disorders -- Periodicals; Nerve Degeneration -- Periodicals; Nervous System Diseases -- Periodicals; Parkinson Disease -- Periodicals; Tremor -- Periodicals; Parkinson, Maladie de -- Périodiques; Parkinson's disease; 616.833
• DOI: 10.1016/j.parkreldis.2018.03.002
• Languages: English
• ISSNs: 1353-8020

Abstract

Abstract: Objectives: To characterize the minimal clinically important change (MCIC) after treatment in cervical dystonia patients using the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS). Methods: Changes in the TWSTRS from an observational study of abobotulinumtoxinA in the routine management of cervical dystonia (NCT01314365) were analyzed using the Patient Global Impression of Change (PGIC) as anchor. Results: For the overall population (N = 304, baseline TWSTRS-Total score 43.4 ± 19.4), the MCIC for the TWSTRS Total score was −11.9 (95%CI: −13.9, −10.0; p < 0.0001). However, thresholds ranged from −3.2 to −18.0 dependent on baseline severity. TWSTRS-Total scores improved linearly by 3 points for every one-point PGIC increase. There was similar linearity between the graded PGIC categories and TWSTRS subscale scores (severity, disability, and pain). Conclusions: A 3-point change is the minimal clinically important change after treatment using TWSTRS as endpoint with higher cutoffs for greater baseline disease severity. For an average trial population (TWSTRS-total: 40–45), a 12-point decrease is clinically meaningful. Highlights: This is the first estimate of the minimal clinically important change for the TWSTRS. The mean MCIC in CD patients (baseline TWSTRS: 43 points) was −11.9 points. MCIC thresholds ranged from −3.2 to −18.0 dependent on baseline severity. TWSTRS Total scores improved linearly by 2.9 points for every 1-point PGIC increase.