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The WHO-5 Wellbeing index performed the best in screening for depression in primary care
  1. Brian A Primack, MD, EdM
  1. University of Pittsburgh School of Medicine
 Pittsburgh, Pennsylvania, USA

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 QUESTION: In the setting of primary care, what is the accuracy of screening questionnaires in identifying depression compared with the accuracy of clinical diagnosis without the aid of questionnaires?

    Design

    Blinded comparison of unaided clinical diagnosis and 3 screening questionnaires with a standardised psychiatric interview.

    Setting

    18 primary care practices in Germany.

    Patients

    431 patients {18–88 years of age (mean age 52.6 y, 63% women)}* who were attending the practices on 1 given day and agreed to complete 3 screening questionnaires.

    Description of tests and diagnostic standard

    Before being seen by a physician, patients completed 3 screening questionnaires: the depression module of the Brief Patient Health Questionnaire (PHQ-9), the General Health Questionnaire, and the World Health Organization (WHO) Wellbeing Index (WHO-5). Physicians treating the patients completed an encounter form to record a clinical assessment, blinded to the screening results. Within 6 days of their visit, patients were contacted via telephone by a psychologist who was blinded to the screening results and physician assessment, for a standardised psychiatric interview using the Composite International Diagnostic Interview.

    Main outcome measures

    Sensitivity, specificity, and predictive values of the 3 depression screening tools and physicians’ unaided clinical diagnosis.

    Main results

    The diagnostic performances of the tests are in the table. The WHO-5 had the greatest sensitivity and negative predictive value of the tests and clinical assessment.

    Diagnostic characteristics of 3 screening questionnaires and unaided clinical diagnosis for detecting depression†

    Conclusions

    In primary care, the World Health Organization Wellbeing Index (WHO-5) performed better than 2 other questionnaires and unaided clinical diagnosis as a depression screening tool. More cases of depression could be identified by using the WHO-5.

    Commentary

    In May 2002, the US Preventive Services Task Force recommended screening all adults for depression. In this study, Henkel et al provide a timely and useful model for evaluating different screening measures. They find that unaided primary care providers detect depression with only 65% sensitivity, emphasising the need for depression screening tests.

    Of the 3 tests evaluated, it is not surprising that the WHO-5 had the best sensitivity and negative predictive value, since it is perhaps the broadest of the measures.1 Participants are asked to agree or disagree with such statements as “I feel calm and relaxed.” Such general statements improve sensitivity and negative predictive value at the cost of specificity and positive predictive value.

    However, others still prefer the PHQ-9 as an overall screening test. It has been found to have sensitivity and specificity as high as 88% each, and despite its brevity, to be useful in grading the severity of depression.2

    Other screening tests not used in this study also merit consideration for further study. One clinically useful measure is the BDI-PC (Beck Depression Inventory for Primary Care).3 It consists of 7 questions and can be completed in a few minutes. Since brevity is indeed important in the primary care arena, the 2 question PRIME-MD (Primary Care Evaluation of Mental Disorders) depression screen, which has been shown to be useful when combined with a 4 question follow up screen, should also be further evaluated.4

    Finally, it is essential to compare the utility of the various depression screening measures in different populations, because patients of different ages, sexes, and cultural backgrounds respond differently to such screens.5

    References

    View Abstract

    Footnotes

    • Sources of funding: German Federal Research Ministry; Pfizer; Novartis.

    • For correspondence: Dr V Henkel, Ludwig-Maximilians-University Munich, Munich, Germany. verena.henkel{at}psy.med.uni-muenchen.de

    • Abstract and commentary also appear in ACP Journal Club.

    • * Information provided by author.

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