Translation, cross-cultural adaptation, and validation of the Italian version of the Synkinesis Assessment Questionnaire in individuals with peripheral facial palsy

BACKGROUND: After peripheral facial palsy, the onset of facial synkinesis results in aesthetic disfigurement and local muscle tension or pain, with possible deterioration of patient's well-being and social participation. The availability of valid instruments to evaluate patient-reported severity of facial synkinesis is important to capture the subjective perception of facial impairment. AIM: To generate and validate an Italian version of the Synkinesis Assessment Questionnaire, a patient-reported outcome measure to assess patient-perceived severity of facial synkinesis after peripheral facial palsy. DESIGN: Observational study. SETTING: Outpatient clinic of a Rehabilitation Unit. POPULATION: Seventy-five patients with peripheral facial palsy. METHODS: Through a process of translation and cross-cultural adaptation, we generated the Italian version of the questionnaire (SAQ-IT) and administered it twice to patients with peripheral facial palsy. We evaluated the clinical severity with the Sunnybrook Facial Grading System (SFGS) and the physical and social/well-being function with the two subscales of the Facial Disability Index (FDI-PHY and FDI-SWB, respectively). RESULTS: Cronbach's alpha was 0.87. Item-total correlations ranged from 0.30 to 0.70, while inter-item correlations ranged from 0.15 to 0.82, with an average value of 0.48. Test-retest reliability showed an Intraclass Correlation Coefficient of 0.946 (95% confidence interval: 0.916-0.966). The minimum detectable change (with a 95% confidence level, MDC95) was 13.14 points. The correlation between SAQ-IT and the SFGS synkinesis subscore was rho=0.74, while that with the SFGS composite score was rho=0.25, with the FDI-PHY rho=-0.11 and with the FDI-SWB rho=-0.13. CONCLUSIONS: Our study validates the SAQ-IT in Italian-speaking individuals with peripheral facial palsy, confirming its acceptable psychometric properties, and providing the MDC95. CLINICAL REHABILITATION IMPACT: The availability of a valid instrument for the evaluation of patient-perceived severity of facial synkinesis plays an important role in the definition of tailored rehabilitative interventions after peripheral facial palsy.