Development of a self-report scale of spasticity
Steve Barker1, Mike Horton, Ruth M Kent
1Academic Unit of Musculoskeletal and Rehabilitation Medicine, University of Leeds, Leeds, UK.
Background:
Although the Modified Ashworth Scale is the most common instrument used to grade spasticity, it is unsuitable for busy follow-up clinics, longer term follow-up, or community surveys.
Objectives:
To establish a simple questionnaire that would indicate the presence and extent of spasticity and would be suitable for use in everyday outpatient clinical practice and/or community follow-up.
Methods:
Qualitative exploration of the experience and impact of spasticity among stroke patients led to the development of a short questionnaire. Rasch analysis was performed on the data and the scale items were externally validated by correlation with comparator measures.
Results:
Forty-eight subjects were recruited for the qualitative interviews, half of whom were more than 2 years post stroke. Interviews generated items relating to spasticity that were categorized into pain, spasm, fatigue, restricted movement, loss of balance, and altered appearance. Eight items were chosen for the draft questionnaire. Five hundred questionnaires were sent, and 188 (38%) were returned. The mean age of the 188 responders was 72.6 years. In regard to health, 18.5% reported that they were in good or excellent health, and 49.7% reported only fair or poor health. Data from the 8-item scale were fitted to the Rasch measurement model. Initial fit of the 8 items was good, and all the assumptions of the model were satisfied. A strong and significant gradient was found between the summed 8-item scale and self-reported health.
Conclusions:
A short self-perceived scale for spasticity has been developed from grounded theory, which satisfies the most rigorous standards for measurement with fit to the Rasch model.
