Prognosis

1D

PROGNOSIS
Adrienne Randolph, Heiner Bucher, W. Scott Richardson, George Wells, Peter Tugwell, and Gordon Guyatt
The following EBM Working Group members also made substantive contributions to this section: Deborah Cook, Jonathan Craig, and Jeremy Wyatt

IN THIS SECTION
Finding the Evidence Are the Results Valid? Was the Sample of Patients Representative? Were the Patients SufficientlyHomogeneous With Respect to Prognostic Risk? Was Follow-up Sufficiently Complete? Were Objective and Unbiased Outcome Criteria Used? What Are the Results? How Likely Are the Outcomes Over Time? How Precise Are the Estimates of Likelihood? How Can I Apply the Results to Patient Care? Were the Study Patients and Their Management Similar to Those in My Practice? Was Follow-up Sufficiently Long?Copyright © 2002 by the American Medical Association

Can I Use the Results in the Management of Patients in My Practice? Cinical Resolution

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USERS ’ G UIDES TO THE M EDICAL L ITERATURE

CLINICAL SCENARIO
Age 71, a Prior Stroke: What Is the Prognosis?

You are a Swiss internist seeing a 71-year-old man recovering from a right
lower lobe pneumonia. The patient, who suffered aright hemispheric stroke 1 year ago, has little function of his left arm but is able to walk with a crutch. He is in sinus rhythm. For at least 15 years, he had hypertension that probably was poorly controlled. His echocardiogram has revealed left ventricular hypertrophy and mild left ventricular dysfunction. A Doppler examination of his carotid arteries shows nonsignificant stenosis of less than50% bilaterally. He takes aspirin 300 mg per day, an angiotensin-converting enzyme (ACE) inhibitor, and a thiazide diuretic now control his hypertension. From a lively discussion with the patient, you learn that he is a connoisseur of French wines and that since his early retirement he spends several months each year in Southern France, where he owns a little cottage. The patient grumbles that sincethe stroke, “things are not going the way they should” and you try to console him. Later on, speaking to the patient’s wife, you find she is concerned about her husband’s difficulty accepting his disability. She feels that owning two residences, with all of the commuting between them, is too much for both of them. The back-and-forth driving and the care for the two houses has completely becomeher burden, and she states that the pneumonia was the “proof for her husband’s exhaustion.” She feels that information about his risks of a recurrent stroke and death could help him and his family to “settle things.” Because your knowledge about the prognosis of survivors of stroke is vague, you tell the patient’s wife that you will obtain specific information to address her concerns, and youpromise to report back to her and to the patient.

Copyright © 2002 by the American Medical Association

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FINDING THE EVIDENCE
Your hospital does not offer access to Best Evidence or the Cochrane Library, but at least you have an Internet connection. During a break, you connect to the Internet and to MEDLINE at the US National Library of Medicine Web site via PubMed.You enter the term “stroke” and, using the thesaurus, you find the correct Medical Subject Heading (MeSH) term, “cerebral infarction.” Combining the search with the terms “epidemiology,” “recurrence,” and “prognosis” yields a number of relevant results. You identify one interesting article, “Long-Term Risk of Recurrent Stroke After a First-ever Stroke,” from the Oxfordshire Community Project andobtain a copy from the library.1 Clinicians help patients in three broad ways: by diagnosing what is wrong with them, by administering treatment that does more good than harm, and by giving them an indication of what the future is likely to hold. Clinicians require studies of patient prognosis—those examining the possible outcomes of a disease and the probability with which they can be expected...