Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2006 Dec;2(4):557-564.
doi: 10.2147/nedt.2006.2.4.557.

Item Response Analysis of the Inventory of Depressive Symptomatology

Ira H Bernstein  1 , A John Rush, Carmody J Thomas, Ada Woo, Madhukar H Trivedi
Affiliations

Item Response Analysis of the Inventory of Depressive Symptomatology

Ira H Bernstein et al. Neuropsychiatr Dis Treat. 2006 Dec.

Abstract

BACKGROUND: Both the clinician (IDS-C(30)) and self-report (IDS-SR(30)) versions of the 30-item Inventory of Depressive Symptomatology have acceptable psychiatric properties and have been used in various clinical studies. These two scales, however, have not been compared using item response theory (IRT) methods to determine whether the standard scoring methods are optimal. METHODS: Data were derived from 428 adult public sector outpatients with nonpsychotic major depressive disorder. The IDS-C(30) and IDS-SR(30) were compared using Samejima's graded response model. RESULTS: A model was constructed jointly fitting the IDS-C(30) and IDS-SR(30). An improvement in scale performance was obtained by grouping selected items into domains (specifically sleep, psychomotor, and appetite/weight domains) analogous to the standard scoring of the 16-item Quick Inventory of Depressive Symptomatology. CONCLUSIONS: For the IDS-C(30) and IDS-SR(30), standard scoring (ie, computing total score using all individual items) provides simplicity, comparability to published data, and a basis for clinical decision making. The revised scoring method, however, improves the utility of both scales when comparing groups as it provides explicit tests of item parameters.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Boundary functions for a four-alternative item.
Figure 2
Figure 2
Plot of successive eigenvalues (scree) for the IDS-C30, IDS-SR30, and randomly generated data (parallel analysis).
Figure 3
Figure 3
Scatter plot of the IDS-C30 scored by item response theory (IRT) vs the IDS-C30 scored by classical test theory (CTT).
Figure 4
Figure 4
Test information functions for the IDS-C30 and the QIDS-C30.
See this image and copyright information in PMC

References

    1. [APA] American Psychiatric Association . Diagnostic and Statistical Manual of Mental Disorders. 4th ed. Washington DC: APA; 2000. text revision.
    1. Bernstein IH, Rush AJ, Carmody TJ, et al. Clinical vs. self-report versions of the Quick Inventory of Depressive Symptomatology in a public sector sample. J Psychiatr Res. 2006. doi:10.1016/j.jpsychires.2006.04.001. - PMC - PubMed
    1. Carmody TJ, Rush AJ, Bernstein IB, et al. The Montgomery Asberg and the Hamilton ratings of depression: a comparison of measures. Eur Neuropsychopharmacol. 2006a;14:601–11. - PMC - PubMed
    1. Carmody TJ, Rush AJ, Bernstein IH, et al. Making clinicians lives easier: guidance on use of the QIDS self-report in place of the MADRS. J Affect Disord. 2006b;95:115–18. - PMC - PubMed
    1. Hamilton M. A rating scale for depression. J Neurol Neurosurg Psychiatry. 1960;23:56–62. - PMC - PubMed