[Translation and psychometric testing of the Rotator Cuff Quality-of-Life Measure (RC-QOL) for use in German-speaking...

The evaluation of quality of life is an established criterion for evaluation of therapeutic measures. Starting from the English-speaking area a great number of different patient-based outcomes measures were developed to specifically question disorders of the musculoskeletal system and the results of treatment. Because of the lack of a German measurement tool for patients with rotator cuff disease the translation and the psychometric testing following international guidelines of the 34-item, multidimensional, English Rotator Cuff Quality-of-Life Measure (RC-QOL) was undertaken. Reliability (test-retest reliability, internal consistency), validity, practicability and acceptance of the German version of the RC-QOL were tested by 102 patients with an impingement syndrome after translation and cross-culture adaptation of the English original questionnaire. In addition, the SF-36, the Constant and UCLA scores were evaluated. Between the evaluations there was no significant difference; the Pearson correlation coefficient was 0.89 for the test-retest reliability. The internal consistency showed a high homogeneity with a Cronbach Alpha-coefficient of 0.98. A Pearson correlation coefficient between 0.67-0.76 registered a high correlation with the physical subscales of the SF-36, the Constant and the UCLA scores. The mean time required for completing the RC-QOL was 12 minutes; mean time required for evaluation was 10 minutes. The questionnaire was incompletely answered by 16 patients (15.6%). A total of 120 items (3.5%) were left unanswered. After successful translation and psychometric testing of the German version of the Rotator Cuff Quality-of-Life Measure (RC-QOL) a multidimensional measurement tool for evaluating the quality of life of German-speaking patients with pathology of the rotator cuff is available.