This study by Marc et al.1 developed and tested a Haitian-Creole translation of the PHQ-9 in men who have sex with men (MSM) living in the Republic of Haiti. The investigators demonstrated unidimensionality of the translated PHQ-9, moderately high internal consistency reliability (α=0.78), preliminary evidence of construct validity (i.e., greater depression in HIV-positive subjects), and no evidence of differential item functioning (DIF) across age, education, sexual orientation or HIV status.
The PHQ-9 has become one of the most widely-used depression measures due to its brevity, inclusion of the nine criteria for major depressive disorder (MDD), utility as a screening, severity, and outcome measure, and public domain status.2 The PHQ-9 has been translated into more than 80 languages (many available at www.phqscreeners.com). Because it is difficult to obtain funding solely for translations, new translations of a measure are often developed as part of studies funded for other reasons (e.g., epidemiological research, multi-national pharmaceutical trials, or by investigators with an interest in conditions assessed principally by patient-report). Also, when a measure has already been widely translated, a publication validating a new translation has added value when it provides data on a new population (e.g., MSM) or “higher-level” psychometric analyses (e.g., factor analysis and DIF). Most studies examining the factor structure of the PHQ-9 have found it to be unidimensional; thus, even though MDD comprises several types of symptoms (e.g., somatic, affective, cognitive), it appears the MDD syndrome is captured by a single overarching construct. One implication is that the clinician need not decide if somatic symptoms are due to a comorbid medical disease or depression, but can use an inclusive approach to counting all symptoms towards a diagnosis of MDD.3 Fewer studies have examined DIF for the PHQ-9, and these have typically (but not invariably) shown that the PHQ-9 items perform similarly across most demographic and disease subgroups. Patient-reported outcome measures like the PHQ family of scales and the NIH PROMIS measures4 (www.nihpromis.org) are becoming increasingly important,5 and valid translations are necessary for evaluating and improving global health.
REFERENCES
Marc LG, Henderson WR, Desrosiers A, Testa MA, Jean SE, Akom EE. Reliability and validity of the Haitian Creole PHQ-9. J Gen Intern Med 2014; (Article SPI #2951)
Kroenke K, Spitzer RL, Williams JBW, Löwe B. The Patient Health Questionnaire somatic, anxiety, and depressive symptom scales: a systematic review. Gen Hosp Psychiatry. 2010;32:345–359.1.
Simon GE, Von Korff M. Medical co-morbidity and validity of DSM-IV depression criteria. Psychol Med. 2006;36:27–36.
Cella D, Riley W, Stone A, Rothrock N, Reeve B, Yount S, et al. The Patient-Reported Outcomes Measurement Information System (PROMIS) developed and tested its first wave of adult self-reported health outcome item banks: 2005–2008. J Clin Epidemiol. 2010;63:1179–94.
Glasgow RE, Riley WT. Pragmatic measures: what they are and why we need them. Am J Prev Med. 2013;45:237–43.
Conflict of Interest
The author has no conflicts of interest with the material in this article.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Kroenke, K. Capsule Commentary on Marc et al., Reliability and Validity of the Haitian Creole PHQ-9. J GEN INTERN MED 29, 1691 (2014). https://doi.org/10.1007/s11606-014-2998-3
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11606-014-2998-3