Screening for depression in primary care: a Rasch analysis of the PHQ-9†. (October 2016)

• Record Type: Journal Article
• Authors: Horton, Mike; Perry, Amanda E.
• Is Part Of: BJPsych bulletin. Volume 40:Number 5(2016)
• Page Start: 237
• Page End: 243
• Publication Date: 2016-10
• Subjects: Psychiatry -- Periodicals; Psychiatry -- Great Britain -- Periodicals; 616.8905
• DOI: 10.1192/pb.bp.114.050294
• Languages: English
• ISSNs: 2056-4694

Abstract

Abstract : Aims and method: To explore the modern psychometric properties of the Patient Health Questionnaire (PHQ-9), we used the Rasch analysis in a sample of 767 primary care patients with depression. Results: The analysis highlighted dependency issues between items 1 and 2 ('Little interest or pleasure in doing things' and 'Feeling down, depressed, or hopeless'), and items 3 and 4 ('Trouble falling or staying asleep, or sleeping too much' and 'Feeling tired or having little energy'). Items 1 and 2 displayed an over-discrimination, suggesting their potential redundancy within the complete item set. Clinical implications: In its current format the PHQ-9 displays some problems with regard to its measurement structure among a sample of primary care patients. These problems can be addressed by removing potentially redundant items to deliver a stable screening tool. The results also lend support for the PHQ-2 to be used as a screening tool in a primary care setting.