Psychometric evaluation of the Chinese version of the Fonseca anamnestic index for temporomandibular disorders

Background The Fonseca anamnestic index (FAI) offers a simple, low-cost, patient-reported method for screening temporomandibular disorders (TMDs). Objectives This study described the development of the Chinese version of the FAI (FAI-C) and examined its reliability and validity when compared to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD). Methods The FAI-C was created by translation and cross-cultural adaptation of the English instrument following international guidelines. Psychometric evaluation of the FAI-C was carried out on a sample of 613 patients with TMDs and 57 controls. Reliability of the FAI-C was determined by means of internal consistency and test-retest methods while validity was ascertained by criterion-related validity. Criterion validity was examined via Cohen's kappa, sensitivity and specificity when compared with DC/TMD Axis I diagnoses. Results Cronbach's alpha value (internal consistency) for total FAI-C score was 0.669, and intra-class correlation coefficient (ICC) value (test-retest reliability) was 0.823. For criterion validity, kappa coefficient value was 0.633 while sensitivity and specificity was 95.9% and 71.9%, respectively. Conclusion The Chinese version of the FAI demonstrated acceptable reliability and good validity. The FAI-C could thus be used as an instrument for screening TMDs in Chinese literate populations.