Current issues of ACP Journal Club are published in Annals of Internal Medicine


Diagnosis

2 questions were as good as more questions for detecting depression

ACP J Club. 1998 Jan-Feb;128:10. doi:10.7326/ACPJC-1998-128-1-010


Source Citation

Whooley MA, Avins AL, Miranda J, Browner WS. Case-finding instruments for depression. Two questions are as good as many. J Gen Intern Med. 1997 Jul;12:439-45. [PubMed ID: 9229283]


Abstract

Objective

To compare the test characteristics of a 2-question instrument with those of 6 previously validated instruments for detecting depression.

Design

A blinded comparison of the results from each instrument with the diagnosis of major depression on the basis of a standard interview.

Setting

An urgent-care clinic at a U.S. Veterans Affairs hospital.

Patients

590 consecutive patients (mean age 53 y, 97% men) who visited the urgent-care clinic. Exclusion criteria were concurrent mania or schizophrenia (n = 47) or missing data (n = 7).

Description of tests and diagnostic standard

Patients were given a self-report questionnaire that included the 2-question instrument taken from the Primary Care Evaluation of Mental Disorders Procedure (“During the past month, have you often been bothered by feeling down, depressed, or hopeless?” and “During the past month, have you often been bothered by little interest or pleasure in doing things?”). A positive test result was a “yes” response to either question. Patients also completed the Center for Epidemiologic Studies Depression Scale, long and short versions (CES-D, CES-D-short); the Beck Depression Inventory, long and short versions (BDI, BDI-short); the Symptom-Driven Diagnostic System for Primary Care (SDDS-PC); and the Medical Outcomes Study (MOS) depression measure. The diagnostic standard, the National Institute of Mental Health Quick Diagnostic Interview Schedule (QDIS-III-R), was administered by trained graduate students who were blinded to the result! s of the case-finding instruments.

Main outcome measures

Sensitivity, specificity, likelihood ratios for a positive and negative result, and area under the receiver-operating characteristic (ROC) curve.

Main results

97 patients (18%) were given a diagnosis of major depression on the basis of the QDIS-III-R. The 2-question instrument had a sensitivity of 96% (95% CI 90% to 99%), a specificity of 57% (CI 53% to 62%), and likelihood ratios for a positive and negative result of 2.2 and 0.07, respectively. The 2-question instrument performed less well (area under the ROC curve 0.82, CI 0.78 to 0.86) than the CES-D (0.89, CI 0.85 to 0.92) (P = 0.006), CES-D short (0.87, CI 0.83 to 0.91) (P = 0.034), and MOS (0.89, CI 0.85 to 0.91) (P = 0.004) and was similar to the SDDS-PC, BDI, and BDI-short.

Conclusion

A 2-question case-finding instrument for detecting depression had test characteristics similar to those of 3 previously validated instruments and had worse test characteristics than 3 other previously validated instruments.

Sources of funding: University of California and Department of Veterans Affairs Health Services Research and Development Locally Initiated Programs.

For article reprint: Dr. M.A. Whooley, General Internal Medicine Section, San Francisco Veterans Affairs Medical Center, 4150 Clement Street, 111A1, San Francisco, CA 94121, USA. FAX 415-386-4044.


Commentary

The study by Whooley and colleagues contributes sound new findings that can enhance the detection of depression in primary care. Careful psychometric comparisons showed that a 2-item measure was as effective as more detailed screening instruments in detecting probable cases of major depression. This information can facilitate the detection of clinically important conditions, potentially leading to the effective treatment of affected persons.

This paper reports a technologically sophisticated investigation. It does not, however, address the related practical issues on which its clinical importance is predicated. What actions are indicated, for example, after the practitioner detects a person with probable depression using the 2-item test? Given the high rate of false-positive results, it is imperative that the clinician gather further information before intervening (1).

What should be done, moreover, for persons who do not meet the diagnostic criteria? Emphasis on whether patients meet or do not meet diagnostic criteria might lead to ignoring the important clinical question of how best to intervene for those who are “distressed” but not “depressed.” Referral to mental health professionals who are not biologically oriented may be appropriate when elevated distress, detected by screening instruments, is not accompanied by a psychiatrically diagnosable condition or is attributable to “problems in living.”

Effective case detection and subsequent intervention depend on practitioners routinely looking for distress. The omission of routine screening for depression or other common psychiatric symptoms from usual assessment procedures is a persistent problem in primary care despite repeated efforts (2). Routine investigation of such problems is as deserving of research attention as research in case-detection technology.

Gerald M. Devins, PhD
Clarke Institute of PsychiatryUniversity of TorontoThe Toronto HospitalToronto, Ontario, Canada

Gerald M. Devins, PhD
Clarke Institute of PsychiatryUniversity of TorontoThe Toronto Hospital
Toronto, Ontario, Canada


References

1. Costello CG, Devins GM. Screening for depression among women attending their family physicians. Can J Behav Sci. 1989;21:434-51.

2. McLean PD, Miles JE. Training family physicians in psychosocial care: an analysis of a program failure. J Med Educ. 1975;50:900-2. [PubMed ID: 1152027]