Validation of the Dutch version of the Simple Shoulder Test

Abstract

Background: The Simple Shoulder Test (SST) is an internationally used patient-reported outcome for clinical practice and research purposes. It was developed for measuring functional limitations of the affected shoulder in patients with shoulder dysfunction and contains 12 questions (yes/no). The purpose of this study was to create a Dutch translation of the SST and to assess the reliability and validity.

Materials and methods: The SST was translated into Dutch using forward and backward translations. A consecutive cohort of patients with shoulder problems visiting an orthopedic clinic completed the Dutch version of the SST twice within 28 days. In addition, the Dutch validated versions of the Disabilities of the Arm, Shoulder and Hand, Oxford Shoulder Score, and Constant-Murley shoulder assessment were completed for assessing construct validity.

Results: One hundred ten patients with a mean age of 39 years (SD, 14 years), 72% male, completed the questionnaires. The internal consistency was high (Cronbach α, 0.78). The test-retest reliability was very good (intraclass correlation coefficient, 0.92) (n = 55). The measurement error expressed in the standard error of measurement was 1.18, and the smallest detectable change was 3.3 on a scale from 0 to 12. The construct validity was supported by expected high correlations between the Dutch version of the SST and the Disabilities of the Arm, Shoulder and Hand (r = -0.74) and between the SST and the Oxford Shoulder Score (r = -0.74) and an expected moderate correlation between the SST and the Constant-Murley shoulder assessment (r = 0.59).

Conclusion: The Dutch version of the SST seems to be a reliable and valid instrument for evaluating functional limitations in patients with shoulder complaints.