Goal attainment scaling in the evaluation of treatment of upper limb spasticity with botulinum toxin: a secondary analysis from a double-blind placebo-controlled randomized clinical trial.

Abstract

To examine goal attainment scaling for evaluation of treatment for upper limb post-stroke spasticity with botulinum toxin-A. Secondary analysis of a multi-centre double-blind, placebo-controlled randomized clinical trial. Six outpatient clinics in Australia. Patients (n=90) completing per protocol 2 cycles of treatment/placebo. Mean age 54.5 (standard deviation 13.2) years. Mean time since stroke 5.9 (standard deviation 10.5) years. Intramuscular botulinum toxin-A (Dysport 500-1000U) or placebo given at 0 and 12 weeks. Measurement points were baseline, 8 and 20 weeks. Individualized goal attainment and its relationship with spasticity and other person-centred measures - pain, mood, quality of life and global benefit. A significant treatment effect was observed with respect to goal attainment (Mann-Whitney z=-2.33, p< or = 0.02). Goal-attainment scaling outcome T-scores were highly correlated with reduction in spasticity (rho=0.36, p=0.001) and global benefit (rho=0.45, p<0.001), but not with other outcome measures. Goal-attainment scaling T-scores were lower than expected (median 32.4, interquartile range 29.6-40.6). Goals related to passive tasks were more often achieved than those reflecting active function. Qualitative analysis of goals nevertheless demonstrated change over a wide area of patient experience. Goal-attainment scaling provided a responsive measure for evaluating focal intervention for upper limb spasticity, identifying outcomes of importance to the individual/carers, not otherwise identifiable using standardized measures.