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

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. 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. 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. 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.