Authors: Cameron, Isobel M¹; Crawford, John R²; Lawton, Kenneth³; Reid, Ian C¹

Source: British Journal of General Practice, Volume 58, Number 546, January 2008 , pp. 32-36(5)

Publisher: Royal College of General Practitioners

Abstract:

Background

The 2004 National Institute for Health and Clinical Excellence (NICE) guidelines highlight the importance of assessing severity of depression in primary care.

Aim

To assess the psychometric properties of the Patient Health Questionnaire (PHQ-9) and the depression subscale of the Hospital Anxiety and Depression Scale (HADS-D) for measuring depression severity in primary care.

Design of study

Psychometric assessment.

Setting

Thirty-two general practices in Grampian, Scotland.

Method

Consecutive patients referred to a primary care mental health worker completed the PHQ-9 and HADS at baseline (n = 1063) and at the end of treatment (n = 544). Data were analysed to assess reliability, robustness of factor structure, convergent/discriminant validity, convergence of severity banding, and responsiveness to change.

Results

Both scales demonstrated high internal consistency at baseline and end of treatment (PHQ-9 α = 0.83 and 0.92; HADS-D α = 0.84 and 0.89). One factor emerged each for the PHQ-9 (explaining 42% of variance) and HADS-D (explaining 52% of variance). Both scales converged more with each other than with the HADS anxiety (HADS-A) subscale at baseline (P<0.001) and at end of treatment (P = 0.01). Responsiveness to change was similar: effect size for PHQ-9 = 0.99 and for the HADS-D = 1. The HADS-D and PHQ-9 differed significantly in categorising severity of depression, with the PHQ-9 categorising a greater proportion of patients with moderate/severe depression (P<0.001).

Conclusion

The HADS-D and PHQ-9 demonstrated reliability, convergent/discriminant validity, and responsiveness to change. However, they differed considerably in how they catergorised severity. Given that treatment decisions are made on the basis of severity, further work is needed to assess the validity of the scales' severity cut-off bands.

References: 23 references open in new window

Articles that cite this article?

Keywords: depression; measurement; primary care; severity

Document Type: Research article

DOI: http://dx.doi.org/10.3399/bjgp08X263794

Affiliations: 1: Department of Mental Health, University of Aberdeen, Aberdeen 2: School of Psychology, University of Aberdeen, Aberdeen 3: Department of General Practice and Primary Care, University of Aberdeen, Aberdeen

Publication date: 2008-01-01

More about this publication?

• The British Journal of General Practice is an international journal publishing articles of interest to family practitioners and primary care researchers worldwide. The journal's 2010 Impact Factor is 2.07, making it the world's second most highly cited journal of general practice and primary health care.

  Recent issues: members of the Royal College of General Practitioners receive complimentary access to the British Journal of General Practice. Access is via the members' login area using your RCGP membership details. All users can freely access articles published up to 1 year ago, and the BJGP archive is available via PubMed Central.
  
  Email alerts can be enabled by registering with IngentaConnect. For information, see Help for web users.

• Information for Authors
• Subscribe to this Title
• Membership Information
• BJGP Archive
• ingentaconnect is not responsible for the content or availability of external websites

Related content

• In this: publication
• By this: publisher
• In this Subject: Public Health
• By this author: Cameron, Isobel M ;  Crawford, John R ;  Lawton, Kenneth ;  Reid, Ian C

Website © Publishing Technology. Article copyright remains with the publisher, society or author(s) as specified within the article.

• Terms and conditions
• Privacy policy
• Information for advertisers