Psychometric properties of the 16-item Quick Inventory of Depressive Symptomatology: a systematic review and meta-analysis

Effective management of depression is predicated upon reliable assessment. The Quick Inventory of Depressive Symptomatology (QIDS) is a depression severity scale with both self-rated (QIDS-SR₁₆) and clinician-rated (QIDS-C₁₆) versions. Although widely used in research, the psychometric properties of the QIDS₁₆ have not been systematically reviewed. We performed a systematic review of studies of the psychometric properties (factor structure, internal consistency, convergent validity, discriminant validity, test-retest reliability and responsiveness to change) of the QIDS-SR₁₆ or QIDS-C₁₆. Six databases were searched: MEDLINE, EMBASE, PsycINFO, CinAHL, Web of Science and the Cochrane Central Register of Controlled Trials. Findings were summarised, bias assessed and correlations with reference standards were pooled. 37 studies (17,118 participants) were included in the review. Both versions of the QIDS₁₆ were unidimensional. Cronbach's alpha ranged from 0.69 to 0.89 for the QIDS-SR₁₆ and 0.65 to 0.87 for the QIDS-C₁₆. The QIDS-SR₁₆ correlated moderately to highly with several depression severity scales. Seven studies were pooled where QIDS-SR₁₆ was correlated with the HRSD-17 (r = 0.76, CI 0.69, 0.81) in patients diagnosed with depression. Four studies examined convergent validity with the QIDS-C₁₆. Four studies examined discriminant validity, for the QIDS-SR₁₆ alone. Eighteen studies had at least one author who was a co-author of the original QIDS₁₆ study. Most studies were conducted in the USA (n = 26). The QIDS-SR₁₆ and the QIDS-C₁₆ are unidimensional rating scales with acceptable internal consistency. To justify the use of the QIDS₁₆ scale in clinical practice, more research is needed on convergent and discriminant validity, and in populations outside the USA.