Evidence Based Medicine

Question 1

State the primary purpose of the NHS.

Answer 1

To secure, through resources available, the greatest possible improvement in the physical and mental health of the population

Question 2

Define Evidence Based Practice.

Answer 2

The systematic search for, and appraisal of, best evidence in order to make clinical decisions that might require changes in current practice, while taking into account the individual needs of the patient.

Question 3

Identify the main components of EBM.

Answer 3

• Production of evidence through scientific research and review
• Production and dissemination of evidence based clinical guidelines
• Implementation of evidence based, cost effective practice through education and change management
• Evaluation of compliance with practice guidance through clinical audit

Question 4

Identify the principles of EBM.

Answer 4

1. High quality health care rests on objective and clinically relevant information
2. There is a hierarchy of evidence where some types are stronger than others
3. Scientific data alone is not a sufficient basis for making clinical decisions about individual patients

Question 5

Describe the level of impact of evidence based medicine.

Answer 5

Strategic changes:
1) EMB used by NICE, Scottish Medicine Consortium, All Wales Medicine Strategy Group, to formulate Health Technology Assessments (HTAs) which determine which treatments should be available within the NHS.

2) Primary care and hospital trusts formulate prescribing, care pathways and guidelines based on HTAs

Question 6

Why is EBM now essential ?

Answer 6

• Daily requirement for correct answers to questions about
– The effects of therapy
– The utility of diagnostic tests 
– The prognosis of diseases
– The etiology of disorders

Question 7

List the main criticisms (cons) for EBM, and the response from proponents (pros).

Answer 7

-EBM is ‘old hat’. Clinicians have been using the literature to guide their decisions for a long time. The label is new.
VS
The new focus on EBM ‘formalizes’ that ‘old hat’ process and filters the literature so that decisions are made based on ‘strong’ evidence’.

-EBM identifies statistically significant benefits which may be marginal in clinical practice.
VS
-EBM should be one part of the process. Decisions are based on individual clinical expertise, patient preferences and, when available, good evidence.

-EBM has generated a massive volume of evidence and guidelines which are unmanageable.
VS
-EBM produces expert judgement in a format that clinicians can understand.

-EBM is the mindless application of population studies to the treatment of the individual. It plays down sound clinical judgement.
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-The last step in the EBM process is to decide whether or not the information and results are applicable to your patient and to discuss the results with the patient.

-Often there is no randomized controlled trial or ‘gold standard’ in the literature to address the clinical question, especially where the patient has complex problems.
VS
-Clinicians might consider the ‘evidence pyramid’ and look for the next best level of evidence. Clinicians need to understand that there may be no good evidence to support clinical judgment.

Question 8

What are steps to practicing evidence based medicine ?

Answer 8

• Craft a clinical question (PICO)
• Search the medical literature (medical informatics)
• Find the study that will best answer the question
• Perform a critical appraisal (check for validity and bias)
• Determine how the results will help you care for your patient
• Evaluate the results in your patient or population

Question 9

Describe the evidence pyramid.

Answer 9

From top to bottom:

• Meta-analyses and systematic reviews
• RCTs
• Non-randomised experimental designs
• Cohort studies
• Case-control studies
• Cross-sectional studies
• Case series and case studies
• Personal communication