Evidence Based Practise Flashcards
Why would you add a fixed weight to studies in a meta analysis?
So thay bigger studies have a greater influence
What is an non-inferiority design?
When a RCT is done to see if a drug is ‘not inferior’ to the standard treatment
When would you add ‘random effects’ to a meta analysis?
When there is significant heterogeneity
This accounts for inter-study variability
What do opportunity costs refer to?
Benefits that could have been recieved but that were given up in order to take another course of action
Define health economics
The study of attempts to allocate limited health care resources among unlimited wants and needs to achieve the maximum benefit for society
Should you document an answer for a questions that has been asked?
And why?
Yes
To demonstrate that you have used reliable sources
In case of a complaint (over your own back)
In case the same question is asked again
So others can see
What is a PICO question?
Patient and problem
Intervention
Comparison
Outcome
What is the Crossover type of RCT?
A person will try out both treatments to see which is most effective
Can’t use a drug that could cure a disease….as then they wouldn’t need the other drug!
In economics, what is the other word given for satisfaction?
Utility
What is diminishing marginal utility?
This is the theory that there comes a point where a products cost no longer provides enough satisfaction (utility) to the person specifically
What is an Incident Rate Ratio?
Where the incidence in the exposed group is divided by the incidence in the group that isnt exposed to the treatment (placebo)
The ratio is compared to 1
What is a confidence interval?
A range of values in which we can be confident includes the true value
SE = Standard error
What is a meta-analysis?
A statistical method for combining the results of a number of studies
What is the ‘Willing to pay approach’?
A type of cost-benefit analysis that’s used to compare the outcomes of medical interventions in monetary terms
So how much would somebody pay to extend their lives by 2 years….
If their expectancy was 54……or 95……
There persons whos was 54 is more likely to pay
How do you test for heterogeneity for meta-analysis?
Cochran’s Q test
Finds if there is a significant difference between each studys odds ratio and the fixed effects odds ratio
What’s difference between Intention to Treat and Per-Protocol analysis?
Intention to Treat –> The analysis includes everybody in the trial, including those who didnt comply properly (eg, drop out)
Per-Protocol –> Only includes those who fully complied with the drug/rules
Which type of meta analysis will give smaller studies a greater relative weight?
Random Effects Model
What are the two types of blinding that can occur in RCTs?
Double blind –> Neither the Dr or patient knows which group has what
Single Blind –> Either the patient or Dr doesn’t know what they’ve got
A good example is for surgery….as the surgeon needs to know whats going on!!
What is ICER?
Incremental Cost-Effectiveness Ratio
Used when comparing 2 different treatments
What are the key points in the 3 stages of clinical trials?
Stage 1 –> Generates PK/PD data
Stage 2 –> Patients given the drug
Small study of efficacy
Stage 3 –> Evaluate toxicity and efficacy
What is a QALY?
Quality-Adjusted Life Years
The number of years lived * utility
What does a p-value under 0.05 mean?
The null hypothesis is rejected
With the null hypothesis being that any difference is caused by sampling/experimental errors…….
So a low p-value means that theres a high probability that the result (in the study) is significant
What is the main reason for randomised controlled trials?
To eliminate confounding (bias) and to test for efficacy
What is cost-effectiveness?
The most cost-effective intervention is the one with the greatest effectiveness for the lowest cost
Only NHS costs are considered
Below the line is best!! (see image)
What’s the difference between surrogate endpoints and clinical endpoints?
Clincal –> Reflects the survival or symptomatic status of a patient (eg, has the treatment fully worked?)
Surrogate –> Certain biomarkers, like BP/tumour size, are decreased (or start changing for the good). This isnt always correlated with clinical endpoints, but can often show that the drug is on its way to achieving the clinical endpoint
What assumption should be made when undergoing cost-minimisation analysis?
That the effectivness of the treatments are equal
What are the 4 stages of answering a medicines information enquiry?
Understand the questions
Carry out your research
Prepare your answer
Feedback your answer
Sloppy trial design will increase or decrease the likelihood of what?
Decreases –> Chance of superiority
Increases –> Chance of non-inferiority
