Propriedades de medida da versão português do Brasil do PHQ-9, GAD-7 e PHQ-4 em pacientes com disfunções temporomandibulares

Abstract

Background: Temporomandibular Disorder (TMD) is a multifactorial condition frequently associated with psychosomatic manifestations, including anxiety and depressive symptoms. Accurate assessment of these emotional dimensions is essential for clinical and research purposes. Although the Patient Health Questionnaire (PHQ-9 and PHQ-4) and the Generalized Anxiety Disorder Scale (GAD-7) are widely used internationally, no validated versions are available for Brazilian patients with TMD, representing a significant gap in national research and practice. Objective: To evaluate the measurement properties of the Brazilian Portuguese versions of the PHQ-9, GAD-7, and PHQ-4 in individuals with TMD. Methods: A total of 222 adults diagnosed with TMD based on the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) were evaluated in two sessions. Confirmatory Factor Analysis (CFA) and Cronbach’s α were used to assess structural validity and internal consistency. Test–retest reliability was examined using the Intraclass Correlation Coefficient (ICC), and measurement error was determined through the Smallest Detectable Change (SDC). Construct validity – hypothesis testing was assessed through predefined hypotheses using Spearman’s correlations. Results: All instruments demonstrated excellent test–retest reliability (ICC > 0.85) and adequate internal consistency (Cronbach’s α > 0.75). Construct validity – hypothesis testing was supported, with 75% of the predefined hypotheses confirmed for the GAD-7, PHQ-4, and the cognitive–affective domain of the PHQ-9. CFA indicated acceptable model fit indices for all scales. Conclusion: The Brazilian Portuguese versions of the PHQ-9, GAD-7, and PHQ-4 showed adequate reliability, validity, and internal consistency for assessing emotional symptoms in patients with TMD. The GAD-7 and PHQ-4 are recommended for preferential use until further studies with larger and more diverse samples confirm the construct validity of the PHQ-9.