Translation, cultural adaptation, validity and reliability of the Greek version of the modified Constant Score

The purpose of this study was to produce a modified Greek translation of the CS and to test this version in terms of reliability and validity.

Translation of the modified Constant score testing protocol was done according to established international guidelines. Sixty-three patients with shoulder pain caused by degenerative or inflammatory disorders completed the Greek version of CS along with the Greek versions of SF-12 and Quick Dash Scores and the ASES Rating Scale and were included into the validation process. To assess test-retest reliability, 58 individuals completed the subjective part of the test again after 24-36 hours, while abstaining from all forms of treatment; internal consistency was measured using Cronbach's alpha (α); reliability was assessed with test-retest procedure and the use of Interclass Correlation Coefficient (ICC), whereas the validity of the reference questionnaire was evaluated using Pearson's correlation coefficient in relation to control questionnaires.

There were no major problems during the forward-backward translation of the CS into Greek. The internal consistency was high (Cronbach's alpha 0.92) while the test-retest reliability for the overall questionnaire was also high (intra-class coefficient 0.95). Construct validity was confirmed with high values of Pearson's correlation between CS and Q-DASH (0.84), SF-12 (0.80) and ASES score (0.86) in respect.

A translation and cultural adaptation of CS into Greek was successfully contacted. The Greek version of the modified Constant Score can be a useful modality in the evaluation of shoulder disorders among Greek patients and doctors.