Evidence based medicine

Question 1

what is evidence based medicine

Answer 1

the integration of best research evidence with clinical expertise and patient values

Question 2

why is evidence based medicines important

Answer 2

1. daily need for valid information in clinical settings
2. inadequacy of traditional information sources
3. maybe an increase in diagnostic skills and clinical judgement with time and experience, but a decline in up to date knowledge
4. lack of time for in depth search and evaluation of information

Question 3

what are the 4 steps to practising EBM

Answer 3

1. formulate an answerable question
2. find the best evidence
3. critically appraise the evidence
4. apply to the patient

Question 4

describe the key points in asking good clinical questions

Answer 4

1. patient/problem- how would you describe a group of patients similar to the one in front of you
2. intervention- what main intervention/treatment are you considering
3. comparison- what is the alternative
4. outcome- what are you hoping to accomplish

Question 5

where should you look to find the best evidence

Answer 5

1. tertiary sources- textbooks, guidelines, BNF
2. secondary sources- review of research
3. primary sources- where data was collected

Question 6

what factors should be considered when critically appraising the evidence

Answer 6

1. what are the findings- results section
2. are they reliable- methods
3. are they generalisable/applicable- sample

Question 7

what is the use of statistics in medical reseach

Answer 7

1. quantify the magnitude of an effect- treatment efficacy
   - prognosis
   - diagnostic accuracy
2. statistical significance verus clinical significance

Question 8

what factors are involved in magnitude of effect

Answer 8

1. absolute risk reduction
2. relative risk reduction- often more impressive than absolute risk reduction
   - the lower the event rate in the control group, the larger the difference between relative risk reduction and absolute risk reduction
3. numbers needed to treat

Question 9

what is the numbers needed to treat

Answer 9

number of persons who would have to receive an intervention for 1 to benefit

• 100/ARR (where ARR is %)
• 1/ARR (where ARR is proportion)

Question 10

what is the value of statistics in EBM

Answer 10

1. objective- not swayed by practitioner beliefs
2. take chance into account
3. provide standard tool for making clinical decisions

Question 11

what is the gold standard for research evidence in determining treatment efficacy

Answer 11

meta analysis of systematic reviews- top of hierarchy of evidence