Information: Quality not Quantity Flashcards
EBM
Evidence based medicine
What is EBM ?
Use the best evidence in the scientific literature to provide the best care for an individual patient.
3 principles of evidence based medicine
- High quality health care rests on objective and clinically relevant information.
- There is a hierarchy of evidence where some types are stronger than others.
- Scientific data alone is not a sufficient basis for making clinical decisions.
Early randomised clinical trial
Effectiveness of bloodletting
Describe the 1st clinical trial
200-500 people
Divided into 2 groups by casting lots
Control group - no phlebotomy
Treatment group - as much bloodletting as appropriate
Efficacy assessed by the number of funerals in each group.
Standardised mortality ratio
expected deaths
NB - assumes the 2 populations are equal in terms of age and sex
NNT
Number needed to treat
What is meant by NNT ?
The number of patients who need to be treated in order for one person to benefit.
The larger the NNT the less the benefit.
What is the ideal NNT ?
Ideally NNT is 1.
Everyone who is treated benefits.
Evidence pyramid
Systematic reviews and meta-analyses
Randomised controlled double blind studies
Cohort studies
Case control studies
Cross-sectional studies
Case study, series or report
Read it in a textbook
Somebody told me
Simplest rules to choosing a starting point
Questions found in systematic reviews/ meta-analyses
Clinical practice guidelines
What is a systematic review ?
It attempts to identify, appraise and synthesise all the empirical evidence that meets pre-specified eligibility criteria to answer a given research question.
What do researchers conducting systematic reviews use ?
Explicit methods aimed at minimising bias, in order to produce more reliable findings.
Trial identification
Identified 4 electronic databases :
- Medline
- Human nutrition
- EMBASE
- Allied and Alternative medicine
Why are systematic reviews viewed as gold standard ?
Avoidance and/or the minimisation of bias
What is a meta-analysis ?
A meta-analysis is when results of the individual studies are combined to produce an overall statistic.
Aims of meta-analysis
To provide a precise estimate of the effects of an intervention and to reduce uncertainty.
What is a point estimate ?
(Usually the mean)
Indicates the magnitude of the effect of the experimental intervention compared to the control intervention.
Confidence interval
Uncertainty of point estimate.
A range of values within which we can be reasonably sure that the turn effect actually lies.
Narrow confidence interval
Higher level of confidence in results
Wider confidence interval
Lower level of confidence in results
How to answer a clinical question ?
Systematic reviews or meta-analysis
NICE and SIGN guidelines
Then, only use primary research literature.
NICE
National Institute for Health and Care Excellence
Est. as a special health authority in April 1999
What did NICE do ?
Development and implementation of evidence based guidelines for appropriate clinical practice, public health and social care.
