The 16-item Quick Inventory of Depressive Symptomatology (QIDS), clinician rating (QIDS-C), and self-report (QIDS-SR): A psychometric evaluation in patients with chronic major depression

Background: The 16-item Quick Inventory of Depressive Symptomatology (QIDS), a new measure of depressive symptom severity derived from the 30-item Inventory of Depressive Symptomatology (IDS), is available in both self-report (QIDS-SR₁₆) and clinician-rated (QIDS-C₁₆) formats. Methods: This report evaluates and compares the psychometric properties of the QIDS-SR₁₆ in relation to the IDS-SR₃₀ and the 24-item Hamilton Rating Scale for Depression (HAM-D₂₄) in 596 adult outpatients treated for chronic nonpsychotic, major depressive disorder. Results: Internal consistency was high for the QIDS-SR₁₆ (Cronbach's α = .86), the IDS-SR₃₀ (Cronbach's α = .92), and the HAM-D₂₄ (Cronbach's α = .88). QIDS-SR₁₆ total scores were highly correlated with IDS-SR₃₀ (.96) and HAM-D ₂₄ (.86) total scores. Item-total correlations revealed that several similar items were highly correlated with both QIDS-SR₁₆ and IDS-SR₃₀ total scores. Roughly 1.3 times the QIDS-SR₁₆ total score is predictive of the HAM-D₁₇ (17-item version of the HAM-D) total score. Conclusions: The QIDS-SR₁₆ was as sensitive to symptom change as the IDS-SR₃₀ and HAM-D₂₄, indicating high concurrent validity for all three scales. The QIDS-SR₁₆ has highly acceptable psychometric properties, which supports the usefulness of this brief rating of depressive symptom severity in both clinical and research settings.