Science and Medicine Flashcards
Purpose of the NHS
‘… to secure, through resources available, the greatest possible improvement in the physical and mental health of the population’
What is evidence based medicine ?
Using the best evidence in the scientific literature to provide the best care for an individual patient.
What is scientific method ?
Observation/experiments
Explanation (Hypothesis) which can be tested
Prediction
Experimentation and data interpretation
Confirmation (or not) of hypothesis
Peer review
Publication (conference/academic journal)
What is good science ?
Observation and experiments
Hypothesis (prediction and testing)
Peer review
Publication
What is real science ?
Observation and experiments
Hypothesis (prediction and testing)
[Results not consistent with hypothesis]
[Back to beginning]
Peer review
Publication
Where do the ideas for hypothesis come from ?
‘Standing on the shoulders of giants’
Invention of a new technique
Intuition/hunch/luck
Funding bodies which control research
[Pharmaceutical industry/ government/ charities]
What is tamiflu ?
An antiviral drug (produced against Swine flu) marketed by Roche
Types of bias
Selection bias
Attrition bias - patients drop out
Reporting bias
Performance bias - did patents know about the trial
Detection bias
What were some bad science examples in the production of Tamiflu ?
The trials were too small
No published protocols
Placebo capsules contained dehydrocholic acid and dibasic calcium phosphate dihydrate.
Authors of clinical study reports cannot be identified.
Missing statistical analyses
Pfizer Neurontin original license
The control of partial seizures in epilepsy - used in conjunction with other anti-epileptic drugs (anti-convulsants)
What was wrong with the Pfizer Neurontin drug ?
It was sold as treatment for many other things as well as epilepsy, which was not what the original license was for.
e.g pain, bipolar disorder, restless leg syndrome, migraine
Importance of evidence based medicine in the provision of care
EBM allows the integration of good quality published evidence with clinical expertise and the opinions and values of the patients and their families or carers.
Effect of bias on scientific research
Bias can cause the results of a scientific study to be disproportionately weighted in favor of one result or group of subjects.
What is a primary study ?
An experiment where a procedure is performed on a patient in artificial, controlled surroundings where the effects of varying one condition can be measured.
Describe primary studies
Direct experimentation
[In vitro models / In vivo testing]
Clinical trials
Surveys
In vitro models
Molecular biology, cell & tissue culture, isolated tissue and organs.
In vivo testing
Animal models and volunteers (artificial control over biological variables)
Clinical trials
Drug treatments and follow ups
Describe secondary studies
Research overviews
- Review
- Systematic review
- Meta-analysis
Review
Expert summary of a number of research studies
Systematic review
Objective analysis of all qualifying primary research studies
Meta-analysis
Integrated analysis of the numerical data from all qualifying studies.
Difference between primary and secondary studies
Primary studies involve :
-Direct experimentation
-Clinical trials
-Surveys
whereas Secondary studies involve :
- Research overviews
How can you asses the accuracy of information ?
Refereed paper
Group of old professors
Systematic review
Randomised control trial
Meet somebody in the Union
Read a textbook
What is an evidence pyramid ?
It is like a hierarchy of quality from worthless up to the best.
Where possible you should try to get the best possible evidence from as high up the pyramid as possible.
Describe the layers of the evidence pyramid from bottom to top
BOTTOM
‘I read it in a textbook’
‘Somebody told me’
Cohort studies
Case control studies
Cross sectional studies
Case studies, series or report
Systematic reviews and meta-analyses
Randomised controlled double blind studies
TOP
What is a peer review ?
Process of subjecting an author’s scholarly work or ideas to the scrutiny of anonymous referees, who are experts in the field.
Purpose of peer review
Ensures that authors meet the standards of their discipline and of science generally.
Leads to publication in an academic journal : Nature, Lancet, BMJ, JAMA etc.
Name the infamous non-paper
Wakefield MMR
8/12 parents convinced the onset of problems coincided with the MMR jab.
What is the MMR controversy ?
MMR vaccination was linked to the development of autism.
Early report published in the Lancet in February 1998 by Wakefield et al. from the Royal Free Hospital.
What happened after the Wakefield paper was released ?
A review was published questioning the safety of the immunisation programme (Wakefield 2011)
The tabloid press suggested that medical opinion was divided on the safety of the MMR vaccination.
95% of children with the measles virus in the gut had MMR as their only documented exposure (Wakefield 2002)
Identification of a distinct group of children with autism resulting from MMR (Shattock 2002)
Example that expert review is subjective
Tabloid press implied 50:50 split, but in fact 99% thought MMR OK only 1% did not. Shattock et al same group as Wakefield.
Why is MMR delivered as a 3 in 1 vaccine ?
MMR is free on the NHS
Single doses are not
more chances if drop outs if vaccinate for each separately.
Single vaccines are less safe than MMR because they leave children vulnerable to dangerous diseases for longer
What is more dangerous measles or MMR ?
Measles
How to read a scientific study ?
Why was the study done ?
What clinical question were the authors addressing ?
What type of study was it ?
Was the design appropriate to the research ?
Are the conclusions justified ?
