Are Scores on English and French Versions of the PHQ-9 Comparable? An Assessment of Differential Item Functioning
Open Access
- 14 December 2012
- journal article
- research article
- Published by Public Library of Science (PLoS) in PLOS ONE
- Vol. 7 (12), e52028
- https://doi.org/10.1371/journal.pone.0052028
Abstract
Medical research increasingly utilizes patient-reported outcome measures administered and scored in different languages. In order to pool or compare outcomes from different language versions, instruments should be measurement equivalent across linguistic groups. The objective of this study was to examine the cross-language measurement equivalence of the Patient Health Questionnaire-9 (PHQ-9) between English- and French-speaking Canadian patients with systemic sclerosis (SSc). The sample consisted of 739 English- and 221 French-speaking SSc patients. Multiple-Indicator Multiple-Cause (MIMIC) modeling was used to identify items displaying possible differential item functioning (DIF). A one-factor model for the PHQ-9 fit the data well in both English- and French-speaking samples. Statistically significant DIF was found for 3 of 9 items on the PHQ-9. However, the overall estimate in depression latent scores between English- and French-speaking respondents was not influenced substantively by DIF. Although there were several PHQ-9 items with evidence of minor DIF, there was no evidence that these differences influenced overall scores meaningfully. The PHQ-9 can reasonably be used without adjustment in Canadian English- and French-speaking samples. Analyses assessing measurement equivalence should be routinely conducted prior to pooling data from English and French versions of patient-reported outcome measures.Keywords
This publication has 51 references indexed in Scilit:
- Optimal cut-off score for diagnosing depression with the Patient Health Questionnaire (PHQ-9): a meta-analysisCMAJ : Canadian Medical Association Journal, 2011
- Reliability and validity of the Thai version of the PHQ-9BMC Psychiatry, 2008
- Psychometric comparison of PHQ-9 and HADS for measuring depression severity in primary careBritish Journal of General Practice, 2008
- Validation of the Patient Health Questionnaire-9 for depression screening among Chinese AmericansComprehensive Psychiatry, 2007
- Differential Association of Cognitive and Somatic Depressive Symptoms With Heart Rate Variability in Patients With Stable Coronary Heart Disease: Findings From the Heart and Soul StudyPsychosomatic Medicine, 2007
- Screening for Depression in Medical Settings with the Patient Health Questionnaire (PHQ): A Diagnostic Meta-AnalysisJournal of General Internal Medicine, 2007
- The Patient-Reported Outcomes Measurement Information System (PROMIS)Medical Care, 2007
- Do Self-Report Instruments Allow Meaningful Comparisons Across Diverse Population Groups?Medical Care, 2006
- The PHQ-9Journal of General Internal Medicine, 2001
- Cutoff criteria for fit indexes in covariance structure analysis: Conventional criteria versus new alternativesStructural Equation Modeling: A Multidisciplinary Journal, 1999