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Centre for Evidence-
Based Medicine

Diagnosis: Clinical Scenario

You are a nurse practitioner in a primary care setting. You are familiar with a number of validated instruments to detect depression. However, a colleague describes a 2-question instrument that she feels is as effective in detecting probable cases of major depression and would be much quicker to use. You decide to investigate the instrument and its properties further.

You pose the question, in patients with suspected depression what is the accuracy of a two-question case-finding instrument for depression compared with six previously validated instruments?

Searching terms and evidence source:
You search MEDLINE using the terms "depression" or "depressive disorder" and come up with 10537 articles. Because you are interested in finding this 2-question tool, you add "sensitivity and specificity" and "questionnaire". When these terms are joined, you still have 58 articles - too many to quickly find the tool. When you join the above search terms with "primary care" as a text word, or "primary health care", the results are narrowed to six, a more manageable retrieval situation. From the six, you find the following paper: 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;12:439-45.

Read the article and decide:

  1. Is the evidence from this study valid?
  2. If valid, is this evidence important?
  3. If valid and important, can you apply this evidence in caring for your patient?

Continue to completed worksheet