Linguistic Validation, Adaptation, and Reliability of the Liverpool Elbow Score’s Patient-Answered Questionnaire in Bulgarian the Bulgarian Les-Paq Questionnaire

Abstract Background There is a lack of upper-limb organ specific patient-reported questionnaires that are linguistically validated and culturally adapted for the Bulgarian population. The Liverpool Elbow Score (LES) is a mixed elbow-specific score with excellent psychometric properties of the patient-answered questionnaire (PAQ). There is no Bulgarian version. The aim of this study was to perform a linguistic validation and cultural adaptation of the LES−PAQ in Bulgarian, and to test the validity and reliability of the Bulgarian version. Materials and Methods The study was conducted in a single institution. Participant selection criteria were defined – included were mentally healthy adult patients with a diagnosis of osteochondritis dissecans of the radiocapitellar joint, elbow arthritis, lateral epicondylitis and elbow contracture. Excluded were patients with coexisting upper limb conditions, illiterate and non-native Bulgarian speakers. The Bulgarian LES−PAQ was created. The process consisted of forward translation, reconciliation and backward translation. An expert committee agreed upon a pre-final Bulgarian version. A final version was decided after cultural adaptation. The psychometric properties and reliability of the Bulgarian LES−PAQ was tested. Results 101 patients were included in this study. We did not observe a ceiling or floor effect. Cronbach’s α coefficient was 0.858. Intraclass correlation coefficient was 0.864 (95% CI 0.77 to 0.92; p < 0.05). A moderate negative correlation was revealed between the LES-PAQ and the DASH (r = -0.591, p < 0.05), and a high positive correlation with SF-12 (r = 0.867, p < 0.001). Conclusion The Bulgarian LES−PAQ is a reliable and valid instrument for assessing elbow conditions such as osteochondritis dissecans of the radiocapitellar joint, elbow arthritis, lateral epicondylitis and elbow contracture. It may assist Bulgarian healthcare professionals in both research and daily work.