The bi-factor structure of the 17-item Hamilton Depression Rating Scale in persistent major depression; dimensional measurement of outcome

Nixon, Neil; Guo, Boliang; Garland, Anne; Kaylor-Hughes, Catherine; Nixon, Elena; Morriss, Richard

Abstract

Background:
The 17-item Hamilton Depression Rating Scale (HDRS17) is used world-wide as an observer-rated measure of depression in randomised controlled trials (RCTs) despite continued uncertainty regarding its factor structure. This study investigated the dimensionality of HDRS17 for patients undergoing treatment in UK mental health settings with moderate to severe persistent major depressive disorder (PMDD).

Methods:
Exploratory Structural Equational Modelling (ESEM) was performed to examine the HDRS17 factor structure for adult PMDD patients with HDRS17 score ≥16. Participants (n = 187) were drawn from a multicentre RCT conducted in UK community mental health settings evaluating the outcomes of a depression service comprising CBT and psychopharmacology within a collaborative care model, against treatment as usual (TAU). The construct stability across a 12-month follow-up was examined through a measurement equivalence/invariance (ME/I) procedure via ESEM.

Results:
ESEM showed HDRS17 had a bi-factor structure for PMDD patients (baseline mean (sd) HDRS17 22.6 (5.2); 87% PMDD >1 year) with an overall depression factor and two group factors: vegetative-worry and retardation-agitation, further complicated by negative item loading. This bi-factor structure was stable over 12 months follow up. Analysis of the HDRS6 showed it had a unidimensional structure, with positive item loading also stable over 12 months.

Conclusions:
In this cohort of moderate-severe PMDD the HDRS17 had a bi-factor structure stable across 12 months with negative item loading on domain specific factors, indicating that it may be more appropriate to multidimensional assessment of settled clinical states, with shorter unidimensional subscales such as the HDRS6 used as measures of change.

Citation

Nixon, N., Guo, B., Garland, A., Kaylor-Hughes, C., Nixon, E., & Morriss, R. (2020). The bi-factor structure of the 17-item Hamilton Depression Rating Scale in persistent major depression; dimensional measurement of outcome. PLoS ONE, 15(10), Article e0241370. https://doi.org/10.1371/journal.pone.0241370

• Journal Article Type: Article
• Acceptance Date: Oct 13, 2020
• Online Publication Date: Oct 26, 2020
• Publication Date: Oct 26, 2020
• Deposit Date: Oct 28, 2020
• Publicly Available Date: Oct 28, 2020
• Journal: PLOS ONE
• Electronic ISSN: 1932-6203
• Publisher: Public Library of Science
• Peer Reviewed: Peer Reviewed
• Volume: 15
• Issue: 10
• Article Number: e0241370
• DOI: https://doi.org/10.1371/journal.pone.0241370
• Keywords: General Biochemistry, Genetics and Molecular Biology; General Agricultural and Biological Sciences; General Medicine
• Public URL: https://nottingham-repository.worktribe.com/output/4995619
• Publisher URL: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0241370