Lessons learned during the cross-cultural adaptation of the American Shoulder and Elbow Surgeons shoulder form into German.

Cross-cultural adaptation and testing of reliability and validity were performed by use of a sample of 118 patients after shoulder arthroplasty. They completed a questionnaire booklet containing the American Shoulder and Elbow Surgeons (ASES) questionnaire, Shoulder Pain and Disability Index (SPADI), Short Form 36, and Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire, and 1 week later, they completed the ASES questionnaire again. The cross-cultural adaptation procedure revealed no major problems. The intraclass correlation coefficients (ICCs) for the subscales for pain and function and for the total score were very high (>0.84); the ICC for the subscale instability was unacceptably low. Function of the contralateral side was consistently better for all items (P < .01). Reliability for both function scales was similar (ICC >0). The ASES scores showed moderate correlation of 0.57 to 0.67 with the various scales of the SF-36 and higher correlation with the DASH (0.84) and SPADI (0.92). The German ASES showed good reliability and validity and can be used for shoulder-specific patient self-assessment in comparison to the contralateral (unaffected) side and provides additional information to objective parameters. The instability domain does not provide any additional clinical information.