Development and Reliability of a Clinician-rated Instrument to Evaluate Function in Individuals with Shoulder Pain: A Preliminary Study

BACKGROUND AND PURPOSE Subacromial impingement syndrome (SIS) is a common and disabling condition in the population. Interventions are often evaluated with patient-rated outcome measures. The purpose of this study was to develop a simple clinician-rated measure to detect difficulties in the execution of movement-related tasks among patients with subacromial impingement syndrome. METHOD The steps in the scale development included a review of the clinical literature of shoulder pain to identify condition-specific questionnaires, pilot testing, clinical testing and scale construction. Twenty-one eligible items from thirteen questionnaires were extracted and included in a pilot test. All items were scored on a five-point ordinal scale ranging from 1 (no difficulty) to 5 (cannot perform). Fourteen items were excluded after pilot testing because of difficulties in standardization or other practical considerations. The remaining seven items were included in a clinical test-retest study with outpatients at a hospital. Of these, four were excluded because of psychometric reasons. From the remaining three items, a measure named Shoulder Activity Scale (summed score ranging from 3 to 15) was developed. RESULTS A total of 33 men and 30 women were included in the clinical study; age range 27-80 years. The intraclass correlation coefficient results for inter-rater reliability and test-retest reliability were 0.80 (95% CI = 0.51-0.90) and 0.74 (95% CI = 0.58-0.84), respectively. The standard error of measurement and minimal detectable change were 1.19 and 3.32, respectively. The scale was linked to the International Classification of Functioning, Disability and Health second level categories lifting and carrying objects (d430), dressing (d540), hand and arm use (d445) and control of voluntary movement (b760). CONCLUSION The Shoulder Activity Scale showed acceptable reliability in a sample of outpatients at a hospital, rated by clinicians experienced in shoulder rehabilitation. The validity of the scale should be investigated in future studies before application to common practice. © 2013 The Authors. Physiotherapy Research International published by John Wiley & Sons Ltd.