Outcome Assessment in Depression: Page 2 of 2
Outcome Assessment in Depression: Page 2 of 2
Table 1 lists some of the measures that are covered most frequently in the clinical literature (PsychINFO and Medline searches). For severity of symptoms, the clinician-rated Hamilton Rating Scale for Depression (HAM-D) and the self-report Beck Depression Inventory (BDI) scale, both invented in the 1960s, are probably the most widely studied and used.1,2 However, items rated in these scales are not representative of the definition of depression as we know it today, using DSM-IV-TR diagnostic criteria.3
The clinician-rated Global Assessment of Functioning (GAF) scale is widely used, especially since its inclusion in Axis V of DSM-IV.
However, there are conflicting reports about inter-rater reliability, especially among clinicians with little or no training with the GAF.4,5
The NIH-funded Sequenced Treatment Alternatives to Relieve Depression (STAR*D) study focused on naturalistic settings and brought to light measures that are compatible with office and clinic settings. Table 2 lists clinical instruments whose utility and practicality have been demonstrated and constitute a solid foundation for a clinically based outcome assessment system. Selected measures for each of the 3 outcome measurement domains (symptom severity, functioning, and quality of life) are briefly reviewed below.
The Quick Inventory of Depressive Symptomatology, Self-Report (QIDS-SR) scale is used to measure symptom severity.6 It is a 16-item self-report questionnaire with Likert-style answer options from 0 to 3. The clinician administered version covers the same questions. The scores are:
• 9 or less (no depression).
• 10 to 17 (mild to moderate depression).
• 18 or higher (severe depression).
In a sample of 596 patients, Rush and colleagues7 found high correlations between the QIDS-SR, and the different versions of the HAM-D (17, 21, and 24 items), at the end of 12 weeks of outpatient treatment for acute depression. In a later study, the investigators demonstrated that the QIDS-SR confirmed response and remission rates as measured by the HAM-D-24 items.8
The Work and Social Adjustment Scale (WSAS) is used to measure functioning.9 It is a 5-item, self-report scale that measures impairment on a visual analog ranging from 0 to 8 in 5 areas: work, home management, social activities, private leisure activities, and ability to form/ maintain relationships. The WSAS is widely used in psychotherapy and psychopharmacology research.
The Quality of Life, Enjoyment, and Satisfaction Questionnaire, Short-Form is a 16-item self-report scale with Likert-style answer options from 1 to 5.10 It provides a subjective rating of satisfaction with 14 life activities in addition to 2 items: satisfaction with medication and overall sense of contentment.
Outcome assessment is a multidimensional proposition that incorporates the patient’s subjective report, clinical judgment, and measurement tools. Outcome assessment should incorporate changes in severity of symptoms, functioning, and quality of life. Regular-interval administration of outcome measurement tools has proved to be beneficial in improving the quality of care that we all hope to provide for our patients.
In this Special Report:
1. Hamilton M. A rating scale for depression. J Neurol Neurosurg Psychiatry. 1960;23:56-62.
2. Beck AT, Ward CH, Mendelson M, et al. An inventory for measuring depression. Arch Gen Psychiatry. 1961;4:561-571.
3. Burt T, IsHak WW. Outcome measurement in mood disorders. In: IsHak WW, Burt T, Sederer LI, eds. Outcome Measurement in Psychiatry: A Critical Review. Washington, DC: American Psychiatric Publishing; 2002.
4. Howes JL, Haworth H, Reynolds P, Kavanaugh M. Outcome evaluation of a short-term mental health day treatment program. Can J Psychiatry. 1997;42:502-508.
5. Söderberg P, Tungström S, Armelius BA. Reliability of global assessment of functioning ratings made by clinical psychiatric staff. Psychiatr Serv. 2005;56:434-438.
6. Rush AJ, Gullion CM, Basco MR, et al. The Inventory of Depressive Symptomatology (IDS): psychometric properties. Psychol Med. 1996;26:477-486.
7. Rush AJ, Trivedi MH, Carmody TJ, et al. One-year clinical outcomes of depressed public sector outpatients: a benchmark for subsequent studies. Biol Psychiatry. 2004;56:46-53.
8. Rush AJ, Trivedi MH, Carmody TJ, et al. Self-reported depressive symptom measures: sensitivity to detecting change in a randomized, controlled trial of chronically depressed, nonpsychotic outpatients. Neuropsychopharmacology. 2005;30:405-416.
9. Mundt JC, Marks IM, Shear MK, Greist JH. The Work and Social Adjustment Scale: a simple measure of impairment in functioning. Br J Psychiatry. 2002;180: 461-464.
10. Endicott J, Nee J, Harrison W, Blumenthal R. Quality of life enjoyment and satisfaction questionnaire: a new measure. Psychopharmacol Bull. 1993;29:321-326.