2 Evidence Based Medicine

Question 1

Define Evidence-Based Medicine

Answer 1

Evidence-based medicine is the idea that clinical practise should be based on the best available evidence.

Question 2

What constitutes “best available evidence”?

Answer 2

Findings of rigourously conducted studies e.g. systematic reviews, giving evidence of EFFECTIVENESS & COST EFFECTIVENESS

Question 3

What were the founding ideas of evidence medicine, what problems had been identified?

Answer 3

Practice was too heavily influenced by:

• Professional Opinion
• Clinical Fashion
• Historical Precedent
• Organisation and Hierarchy

Question 4

What did the errors identified in practice before EBM lead to?

Answer 4

Persistent usage of ineffective interventions
Failure to uptake new effective interventions
Tolerance of huge variation in practice –> INEQUITY

Question 5

Why was the Cochrane Library established?

Answer 5

A need was noted for a register of all ongoing research, specifically RCTs.
The Cochrane logo highlights the fact that the use of corticosteroids in premature pregnancy had been identified as reducing mortality for nearly 20 years before it was implemented into clinical practice.

Question 6

Why are SYSTEMATIC REVIEWS needed (e.g. over narrative reviews)?

Answer 6

1. Narrative reviews can be subjective and biased
2. Not transparent as to how studies were selected
3. Quality of studies used in narrative studies is questionable
4. They can directly address clinical uncertainty
5. They can highlight gaps in research/ poor quality research

Question 7

Why are systematic reviews specifically useful to clinicians?

Answer 7

• Quality control already been done
• Up-to-date information in an authoritative format
• Saves time having to find information from primary studies
• Can help reduce delay between research and implementation

Question 8

How can criticisms of EBM be grouped?

Answer 8

Into PRACTICAL and PHILOSOPHICAL criticisms

Question 9

What are the PRACTICAL criticisms of EBM?

Answer 9

Impossible task to maintain systematic reviews for all specialties

Challenging to disseminate information

RCTs are not always feasible e.g. because of ethical considerations

Lack of scope for BIOPSYCHOSOCIAL model, results often very BIOMEDICAL

Requires good faith in pharmaceutical companies

Question 10

What are the PHILOSOPHICAL criticisms of EBM?

Answer 10

Does not integrate well with most doctor’s reasoning PROBABILISTIC vs DETERMINISTIC. This has a probability of causes that, rather than this causing that.

EBM & NICE guidelines create BLIND FOLLOWERS of GUIDANCE

POPULATION based data does not neccessarily work best for the individual - loss of patient-centred aspect

Loss of autonomy

Can be seen as a way of LEGITIMISING RATIONING - undermining the doctor-patient relationship

Question 11

What are the problems with getting EBM into practice?

Answer 11

• Poor Dissemination - doctors don’t know about it
• Culture/ Autonomy - doctors know but are choosing not to do what the evidence says
• Organisation- managers not enforcing changes
• Commissioning - commissioning has priorities other than evidence-base because of local demands
• Resources not available to implement change