Responsiveness of the shoulder pain and disability index in patients with adhesive capsulitis.

BACKGROUND: Instruments designed to measure the subjective impact of painful shoulder conditions have become essential in shoulder research. The Shoulder Pain and Disability Index (SPADI) is one of the most extensively used scales of this type. The objective of this study was to investigate reproducibility and responsiveness of the SPADI in patients with adhesive capsulitis. METHODS: SPADI test-retest reproducibility was estimated by the "intraclass correlation coefficient" (ICC) and the "smallest detectable difference" (SDD). Responsiveness was assessed by exploring baseline and follow-up data recorded in a recently reported clinical trial regarding hydrodilatation and corticosteroid injections in 76 patients with adhesive capsulitis. "Standardized response mean" (SRM) and "reliable change proportion" (RCP) for SPADI were compared with corresponding figures for shoulder range-of-motion (ROM). The relationship between SPADI and ROM change scores was investigated through correlation and linear regression analyses. RESULTS: Results for test-retest reproducibility indicated a smallest detectable difference of 17 points on the 0-100 scale, and an intraclass correlation coefficient of 0.89. The SPADI was generally more responsive than ROM. Weak to moderately strong associations were identified between SPADI and ROM change scores. According to the regression model, the three variables baseline SPADI, baseline active ROM and change in active ROM together explained 60% of the variance in SPADI improvement. CONCLUSION: This study supports the use of SPADI as an outcome measure in similar settings.

Factor structure of the Shoulder Pain and Disability Index in patients with adhesive capsulitis.

BACKGROUND: The Shoulder Pain and Disability Index (SPADI) is a self-administered questionnaire that aims to measure pain and disability associated with shoulder disease. It consists of a pain section and a disability section with 13 items being responded to on visual analogue scales. Few researchers have investigated SPADI validity in specified diagnostic groups, although the selection of an evaluative instrument should be based on evidence of validity in the target patient group. The aim of the present study was to investigate factor structure of the SPADI in a study population of patients with adhesive capsulitis. METHODS: The questionnaire was administered to 191 patients with adhesive capsulitis. Descriptive statistics for items and a comparison of scores for the two subscales were produced. Internal consistency was analyzed by use of the Cronbach alpha and a principal components analysis with varimax rotation was conducted. Study design was cross-sectional. RESULTS: Two factors were extracted, but the factor structure failed to support the original division of items into separate pain and disability sections. CONCLUSION: We found minimal evidence to justify the use of separate subscales for pain and disability. It is our impression that the SPADI should be viewed as essentially unidimensional in patients with adhesive capsulitis.

Range of shoulder motion in patients with adhesive capsulitis; intra-tester reproducibility is acceptable for group comparisons.

BACKGROUND: Measurements of range of motion play a key role in shoulder research. The purpose of this study is to investigate intra-observer reproducibility of measurements of active and passive range of motion in patients with adhesive capsulitis. METHODS: The study was carried out in a population consisting of 32 patients with clinical signs of adhesive capsulitis. A specified measurement protocol was used, and range of motion in affected and non-affected shoulders was measured twice for each patient with a one-week interval. RESULTS: For most of the investigated individual movements, test-retest differences in range of motion score of more than approximately 15 degrees are not likely to occur as a result of measurement error only. Point-estimates for the intraclass correlation coefficient ranged from 0.61 to 0.93. CONCLUSION: Range of motion of patients with adhesive capsulitis can be measured with acceptable reproducibility in settings where groups are compared. Scores for individual patients should be interpreted with caution.

Hydrodilatation, corticosteroids and adhesive capsulitis: a randomized controlled trial.

BACKGROUND: Hydrodilatation of the glenohumeral joint is by several authors reported to improve shoulder pain and range of motion for patients with adhesive capsulitis. Procedures described often involve the injection of corticosteroids, to which the reported treatment effects may be attributed. Any important contribution arising from the hydrodilatation procedure itself remains to be demonstrated. METHODS: In this randomized trial, a hydrodilatation procedure including corticosteroids was compared with the injection of corticosteroids without dilatation. Patients were given three injections with two-week intervals, and all injections were given under fluoroscopic guidance. Outcome measures were the Shoulder Pain and Disability Index (SPADI) and measures of active and passive range of motion. Seventy-six patients were included and groups were compared six weeks after treatment. The study was designed as an open trial. RESULTS: The groups showed a rather similar degree of improvement from baseline. According to a multiple regression analysis, the effect of dilatation was a mean improvement of 3 points (confidence interval: -5 to 11) on the SPADI 0-100 scale. T-tests did not demonstrate any significant between-group differences in range of motion. CONCLUSION: This study did not identify any important treatment effects resulting from three hydrodilatations that included steroid compared with three steroid injections alone. TRIAL REGISTRATION: The study is registered in Current Controlled Trials with the registration number ISRCTN90567697.