Transcultural Adaptation and Validation of the Fonseca Anamnestic Index in a Spanish Population with Temporomandibular Disorders.

Abstract Background. The Fonseca Anamnestic Index (FAI) offers a simple method to screen temporomandibular disorders (TMD). This study aimed to validate the standard version of the FAI in a Spanish population and to analyze the clinimetric properties of the Spanish version of the FAI in patients with TMD.Methods. The sample consisted of 179 subjects aged over 18 years, of which 119 were diagnosed with TMD and 60 were healthy controls. Construct validity (exploratory factor analysis), internal consistency, test-retest reliability, and concurrent validity were analyzed. To discriminate between patients with and without TMD, Receiver Operating Characteristic (ROC) curve analysis was performed.Results. The Spanish version of the FAI showed construct validity formed by three factors. Cronbach’s alpha was 0.820, indicating good internal consistency. The reliability of the items measured with the weighted kappa coefficient was between 0.588 and 0.899, varying between moderate to almost perfect. The intraclass correlation coefficient (ICC) of the total score was 0.938, indicating excellent reliability. The standard error of measurement (SEM) was 6.42, with a minimum detectable change (MDC) of 12.59 points. The concurrent validity showed a significant correlation with headache, neck pain, vertigo and the Mental Component Summary (SF-12 MCS) of the SF-12. However, the relationship with the Physical Component Summary (SF-12 PCS) was not significant. The ROC curve analysis showed a good accuracy of the FAI in differentiating between healthy and TMD patients with an area under the curve (AUC) = 0.869, corresponding to a cut-off point for the FAI of >35 points, with a sensitivity = 83.19% and a specificity = 78.33%.Conclusions. The Spanish version of the FAI is a valid and reliable instrument for diagnosing people with TMD, with appropriate general clinimetric properties. Discrimination between patients with and without TMD is excellent.