RELIABILITY OF SELF-ADMINISTERED ASSESSMENT METHODS IN SUBACROMIAL IMPINGEMENT

Abstract

Aims: The use of the Oxford Shoulder Score (OSS) and the Shoulder Pain and Disability Index (SPADI), both patient-administered functional scoring systems, have been validated in groups of patients presenting with a variety of shoulder conditions. The aim of the present study is to determine the test-retest reliability for these scoring systems in patients with a clinical diagnosis of subacromial impingement.

Methods: All patients attending a specialist shoulder clinic with a likely diagnosis of subacromial impingement over a ten-week period were sent the OSS and SPADI questionaires in the week prior to their appointment. Those who, after history and physical examination, had a confirmed diagnosis of impingement were asked to complete the scores again prior to treatment. The pre-attendance and attendance scores were then analysed by the Kappa statistic and correlation coefficent for individual items, and by reliability coefficient for the total score.

Results: Thirty-eight patients completed the scoring questionnaires pre-attendance and in the clinic. For the OSS, the Kappa statistic gave poor agreement (0.127) for one question about pain, but moderate to good for the remainder (0.440 to 0.794). Similarly, the correlation coefficient for individual items on the SPADI scale showed one functional item with a result of 0.584, but the other twelve items ranging from 0.668 to 0.947. Taken as scores out of 100, the mean difference in total OSS was 0 (95% CI −2.3 to +2.3), with a coefficient of repeatability of 14.7. The mean difference in SPADI was 1.0 (95% CI −2.23 to + 4.23), the coefficient of repeatability being 20.69.

Conclusions: The OSS and SPADI show good test-retest reliability for individual question items and as overall scores in patients with subacromial impingement.