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Center for Health Sciences
Medical Physiology - Evidence-Based Medicine
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What is EBM?

Patient Care Model
Life-long Learning
Why is EBM Important?
Available Evidence?
EBM Issues

The Well-built Question

The EBM Process
Anatomy of a Question

Finding Evidence

Selecting a Resource
Searching the Resource
Reviewing Search Results
Returning to the Patient

Evaluating Evidence

Evaluating the Validity
Validity Questions


Knowledge Test

Multiple Sclerosis
Case #2
Case #3
Case #4




In the following exercise, click an answer and a pop-up box will appear that contains feedback.

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Case 4: Parkinson's Disease

The Patient

1. Start with the patient - a clinical problem or question arises out of the care of the patient.

A 63-year-old woman returns with a 4-year history of advanced Parkinson 's disease . Currently, her medication is effective for only 4 hours, after which time her tremor becomes more severe, her handwriting "cramped," and her walking worse. She denies involuntary movements with her medication (dyskinesias), falls, or "freezing" of gait. Review of her autonomic nervous system reveals that she has been having constipation and is not eating much fiber or taking any dietary supplements. She has no urinary difficulties or episodes of light-headedness. Her neuropsychiatric review demonstrates no history of depressed mood, anxiety, hallucinations, or significant cognitive impairment. She continues to work part time, is driving, and has no sleep impairment or daytime somnolence from her medication. Her present medication is carbidopa/levodopa, 25/100 mg po tid.

This case represents the typical course of Parkinson ' s disease with the development of motor fluctuations, which occur with disease progression. Other than constipation, there are no major concerns. Adjustment of her medication regimen should relieve her present disability.

The patient's neurologist decides to confirm that the present medication is supported by the best available evidence for treating Parkinson's disease before adjusting her medication regiment.

The Question

2. Construct a well-built clinical question derived from the case.

Based on this scenario, choose the best, well-built clinical question:

A. For an elderly female diagnosed with advanced Parkinson's disease with motor fluctations is levodopa therapy an efficacious treatment for significantly reducing symptoms of motor dysfunction such as tremors and difficulty walking?

B.For a patient diagnosed with Parkinson's disease is levodopa therapy the best therapy?

C. For an elderly female diagnosed with advanced Parkinson's disease is levodopa therapy good for reducing symptoms?

The Resource

3. Launch PIER (From ACP) and conduct a search using the well-built question from Answer A above. (Hint: In point-of-care databases it is best to start by searching for the pre-dominant medical condition, in this case use "Parkinson's disease .")

Based on your PIER search results please answer the following question.

Which of the following are given by PIER with regrard to drug therapy for Parkinson's disease?

A. Consider use of dopamine agonists as first-line treatment, recognizing that there is no consensus on drug management of patients with Parkinson 's disease.

B. Avoid ergot dopamine agonists such as pergolide, cabergoline, and bromocriptine.

C. Recognize that most drugs can be beneficial at any stage of the disease.

D. Recognize that there are no specific algorithms to guide drug management.

E. All of the above

The Evaluation

4. Appraise the evidence for its validity (closeness to the truth) and its applicability (usefulness in clinical practice).

As stated previously, evaluating medical research reports is a complex and time-consuming undertaking. The best resources in the clinical setting are the point-of-care databases which provide pre-evaluated answers to specific clinical questions in the practical time frame needed by a practicing physician.

PIER is a good example of a database providing patient-oriented, evidence-based clinical answers that are pre-evaluated for validity. Evidence in PIER is labeled in one of three levels so clinicians can quickly grasp the reliability of conclusions and recommendations.

Based on your PIER search results please answer the following question.

In PIER what level of evidence is assigned to levodopa therapy as a treatment for a patient with Parkinson's disease?

A. Grade C [preponderance of data derived from level 3 studies]

B. Grade A [preponderance of data derived from level 1 studies]

C. Grade B [preponderance of data derived from level 2 studies]

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