Week 2 workshop - science as evidence

Question 1

evidence-based practice

Answer 1

using the best available evidence in deciding whether a given treatment works and for whom it works.
* Using the best available evidence to decide which of 2 or more treatment options is most effective and affordable.

Question 2

sources of evidence

Answer 2

clinical observations
experimental studies
expert consensus
RCTs
systematic review

Question 3

clinical observations

Answer 3

• Reflect experience
• Influenced by subjectivity and bias
• Show inter-individual variations
• Not always replicable

Question 4

experimental studies

Answer 4

• Objective
• Can demonstrate efficacy
• Tend to be selective
• Experimental control may not be practical outside the lab
• May lack real world generalisability

Question 5

expert consensus

Answer 5

• “In an ideal world, clinical guidelines would be based on evidence derived from rigorously conducted empirical studies.
• In practice, there are few areas of health care where sufficient research-based evidence exists or may ever exist.
• In such situations… guidelines will inevitably have to be based partly or largely on the opinions and experience of clinicians…”
• Gains from experience
• Influenced by subjectivity but reflects peer scrutiny
• Only as good as the source evidence

Question 6

RCTs

Answer 6

• Formal trials of therapy (usually in practice)
• Allows for replication of results
• Allows for systematic review
• Gold standard for clinical evidence

Question 7

systematic review

Answer 7

• Review of all relevant RCTs
• Strictly operationalised
• Public access

Question 8

common sources of unreliable evidence

Answer 8

• Anecdotal evidence
• Personal testimonials
• Intuition

Question 9

what is an RCT

Answer 9

• An experiment in which investigators randomly allocate eligible people into groups to receive (treatment group) or not to receive (control group) interventions that are being compared.
• Results are assessed by comparing outcomes in the treatment and control groups.
• Clear definition of the problem.
• Random (unbiased) allocation into experimental groups.
• Controlled observation (including ‘placebo’ controls).
• Clearly defined outcome measures.

Question 10

patient choice and evidence: is their conflict?

Answer 10

• Patients may choose idiosyncratically
• Evidence may be confusing
• The evidence-based option may be unacceptable (e.g. religious reasons)