Validation of the Brazilian Portuguese version of the Quick Inventory of Depressive Symptomatology and Self-Report (QIDS-SR16) for the Brazilian population

Objectives: To evaluate the psychometric properties of the Quick Inventory of Depressive Symptomatology (QID-SR16), a self-report instrument based on the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) criteria that assesses the severity of depression symptoms, in the Brazilian population. Methods: Participants were 4,400 Brazilians over the age of 15 years recruited for an online survey assessing depressive symptoms during the early phase of the coronavirus disease 2019 (COVID-19) pandemic in Brazil. The internal consistency, construct validity, and convergent and discriminant validity of the QIDS-SR16 were evaluated. Results: The model tested was considered an adequate fit to the data (comparative fit index [CFI] = 0.947, Tucker-Lewis index [TLI] = 0.927, and root-mean-square error of approximation [RMSEA] = 0.051) and its internal consistency was good, with a Cronbach's alpha of 0.71 and an average item correlation of 0.23. The correlations between the total QIDS-SR16 score and the total scores of the Patient Health Questionnaire (PHQ-9) instruments (r = 0.67, p < 0.001), the Posttraumatic Symptoms Checklist (PCL-5) (r = 0.61, p < 0.001), and the Patient-Reported Outcomes Measurement Information System (PROMIS) (r = 0.60, p < 0.001) indicate good concurrent and convergent validity. Conclusion: The QIDS-SR16 has robust psychometric properties in terms of its internal consistency, construct validity, and convergent and discriminant validity. The Portuguese version of the QIDS-SR16 is an adequate instrument for assessment of depressive symptoms in the context of an online survey.