Cross-cultural adaptation, reliability and validity of the German Shoulder Pain and Disability Index (SPADI)

Objective. To cross-culturally adapt the Shoulder Pain and Disability Index (SPADI) from English into German, and to test the reliability and validity of the German version. Methods. Cross-cultural adaptation of the SPADI was performed according to international guidelines. One hundred and eighteen patients who had undergone shoulder arthroplasty, on average 4 yr previously, completed a questionnaire booklet containing the German SPADI, the Short Form 36 (SF-36), the Disability of the Arm, Shoulder and Hand (DASH) questionnaire, and the American Shoulder and Elbow Surgeons (ASES) questionnaire for the shoulder to assess SPADI's construct validity. One week later, they completed the SPADI again to assess test-retest reliability. Results. The six-step cross-cultural adaptation procedure revealed no major problems with the content or language. The intraclass correlation coefficients for the individual items of the SPADI were between 0.68 and 0.89, and that for the SPADI total score was 0.94. The SPADI total score showed a correlation of 0.61-0.69 with the SF-36 physical scales, of 0.88 with the DASH and of 0.92 with the ASES. Conclusions. The German SPADI is a practicable, reliable and valid instrument, and can be recommended for the self-assessment of shoulder pain and function.