Clinical validation of the self-reported 6-item Hamilton Depression Rating Scale (HAM-D6-SR) among inpatients

Abstract

Background: Brief and valid patient-rated symptom scales represent a valuable addition to clinician-rated scales for assessing depression. Studies on the psychometric properties of the self-rated 6-item Hamilton Depression Rating Scale (HAM-D6-SR) have shown promising results for outpatients with depression. The aim of the present study was to evaluate the psychometric properties of the HAM-D6-SR among inpatients using the clinician-rated 17-item Hamilton Rating Scale for Depression (HAMD17) as the gold standard.

Methods: Inpatients with unipolar or bipolar depression completed the HAM-D6-SR and were subsequently rated on the HAM-D17 by trained raters, who were blind to the HAM-D6-SR ratings. The pairs of HAM-D6-SR and HAM-D17 ratings were completed twice during admission to evaluate responsiveness over time. Agreement between the HAM-D6-SR and the clinician-rated HAM-D17-derived HAM-D6 was evaluated using the intraclass correlation coefficient (ICC). Responsiveness was evaluated by means of the Spearman's rank correlation coefficient (rho).

Results: A total of 102 participants completed the HAM-D6-SR at least once (median age: 41 years; 66 % females). The ICC for the HAM-D6-SR and the HAM-D17-derived HAM-D6 was 0.60 (95%CI = 0.30-0.76), with the ICC at the item level ranging from 0.13 (Psychomotor retardation) to 0.75 (Depressed mood). The correlation between the changes in the baseline-endpoint total scores on the HAM-D6-SR and HAM-D17-derived HAM-D6 was rho = 0.59 (p < 0.001).

Limitations: Test-retest reliability and structural validity were not evaluated.

Conclusions: The HAM-D6-SR holds promise as a valid self-report of core depressive symptoms among inpatients and may aid treatment decisions. However, the validity of self-reported psychomotor retardation was poor.

Keywords: Depression; Psychiatric status rating scales; Psychopathology; Quality of life; Self-report.