Criterion validity of the French version of Patient Health Questionnaire (PHQ) in a hospital department of internal medicine.

OBJECTIVES: Depressive disorders are overrepresented among the patients admitted to non-psychiatric units in general hospitals. However, the majority of depressed patients fail to be identified within this care setting. Since a self-administered questionnaire (Patient Health Questionnaire, PHQ-9) has given encouraging results in English and Spanish, new research should test its criterion validity in a French-speaking environment. DESIGN: The study included 292 patients admitted to the internal medicine units of the University Hospitals of Geneva. Each patient filled the PHQ-9; 212 patients also underwent a blinded DSM-IV diagnostic assessment by a psychiatrist. METHODS: In order to assess the validity of PHQ-9 against the gold standard of the psychiatrist's DSM-IV diagnosis, we calculated overall accuracy, sensitivity, specificity, positive predictive value and Cohen kappa coefficients. We also studied the relationship between the PHQ-9 diagnostic and the severity of depression. Finally, analysis focused on the presence of a diagnosis of depression. RESULTS: Within the framework of the study, PHQ-9 showed an acceptable level of specificity. However, its sensitivity in detecting major depression was low (about 50% of false-negative results). As regards the overall presence of depressive disorders, this instrument performed hardly any better (35% of false negatives). Other characteristics of the population under investigation may have affected the data. CONCLUSIONS: The French version of PHQ-9 demonstrated low sensitivity as compared with psychiatrist-established diagnosis of DSM-IV A criterion and major depressive episode.

Prevalence and treatment of depression in a hospital department of internal medicine.

BACKGROUND: Depressive disorders are overrepresented among patients admitted to nonpsychiatric units of general hospitals, but the majority of depressed patients are not identified in this setting. Effective and well-tolerated treatments and reliable diagnostic criteria, together with new assessment tools (self-administered or not), have been developed with encouraging results. Nevertheless, few studies have utilized standardized instruments and extensive clinical interviews by well-trained psychiatrists to assess depression. New research should test these tools in a French-speaking environment. METHODS: The investigation covered 292 patients aged 18-65 who were admitted over a period of 6 months to the internal medicine units of Geneva University Hospitals. Each patient filled in a self-administered questionnaire for depression [Patient Health Questionnaire (PHQ-9)]; 212 patients were also evaluated by a psychiatrist using DSM-IV diagnostic assessment and the Hamilton Depression Rating Scale during the first week of their hospital stay; both assessments were single-blinded. RESULTS: Psychiatric clinical interviews identified a high proportion (26.9%) of depressive disorders (37% among women) for all diagnoses; 11.3% (17.3% among women) of the patients met the DSM-IV criteria for major depression. The PHQ-9 identified depressive disorders among 34.9% of patients (42% among women) and identified a major depressive syndrome among 18.4% of patients (29.6% among women). Physicians in the internal medicine unit identified only about half the depressive patients; at the time of psychiatric examination, fewer than one in four patients was receiving antidepressant therapy. CONCLUSIONS: Our findings confirm the results of previous investigations, which showed that the failure to detect and treat depression is a major health problem among patients admitted to nonpsychiatric units of a general hospital.