Psychometric Properties of the Persian Version of the Simple Shoulder Test (SST) Questionnaire

Background: To validate the Persian version of the simple shoulder test in patients with shoulder joint problems.   Methods: Following Beaton`s guideline, translation and back translation was conducted. We reached to a consensus on the Persian version of SST. To test the face validity in a pilot study, the Persian SST was administered to 20 individuals with shoulder joint conditions. We enrolled 148 consecutive patients with shoulder problem to fill the Persian SST, shoulder specific measure including Oxford shoulder score (OSS) and two general measures including DASH and SF-36. To measure the testretest reliability, 42 patients were randomly asked to fill the PersianSST for the second time after one week. Cronbach’s alpha coefficient was used to demonstrate internal consistency over the 12 items of PersianSST. Results: ICC for the total questionnaire was 0.61 showing good and acceptable testretest reliability. ICC for individual items ranged from 0.32 to 0.79. The total Cronbach’s alpha was 0.84 showing good internal consistency over the 12 items of the PersianSST. Validity testing showed strong correlation between SST and OSS and DASH. The correlation with OSS was positive while with DASH scores was negative. The correlation was also good to strong with all physical and most mental subscales of the SF36. Correlation coefficient was higher with DASH and OSS in compare to SF36. Conclusion: Persian version of SST found to be valid and reliable instrument for shoulder joint pain and function assessment in Iranian population.