Diagnosing and treating depression in general hospitals

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.