Psychometric properties of the Chinese versions of the Quick Inventory of Depressive Symptomatology - Clinician Rating (C-QIDS-C) and Self-Report (C-QIDS-SR)

Background: Developing accurate and time-efficient tools to measure depressive symptoms is important for research and clinical practice. This study aimed to test the psychometric properties of the Chinese version of the 16-item Quick Inventory of Depressive Symptomatology - Clinician Rating (C-QIDS-C) and Self-Report (C-QIDS-SR).

Methods: This study included 998 patients with major depressive disorder (MDD) established using the Mini International Neuropsychiatric Interview (MINI). The severity of depressive symptoms was assessed using the Hamilton Rating Scale for Depression (HAMD), C-QIDS-C and C-QIDS-SR at baseline and 6 weeks later.

Results: Internal consistency (Cronbach's alpha) ranged from 0.73 to 0.82 for C-QIDS-C and C-QIDS-SR at both the baseline and exit. The involvement and energy domains at baseline, and sad mood, concentration/decision making, self outlook, involvement and agitation/retardation domains at exit had the highest item-total correlations across the two C-QIDS scales. The C-QIDS-C and C-QIDS-SR total scores were highly correlated with the HAMD total score at both baseline (r=0.61, p<0.01 and r=0.54, p<0.01, respectively) and exit (r=0.75, p<0.01 and r=0.72, p<0.01, respectively). The C-QIDS-C, C-QIDS-SR and HAMD were equally sensitive to change of depressive symptoms, suggesting high concurrent validity. The C-QIDS-C and C-QIDS-SR showed uni-dimensional measurement properties in exploratory factor analyses at both baseline and exit.

Conclusions: The C-QIDS-C and C-QIDS-SR have excellent psychometric properties and are sensitive measurement of symptom severity in MDD.