1.3+4 Population Science Clinical Trials Flashcards
What do phase 1 studies detect?
Pharmacodynamics
Pharmacokinetics
Major side effects
What do phase 2 studies aim to detect?
Effects and dosages
Common side effects
What do phase 4studies aim to detect?
Monitoring for adverse reactions
Potential new uses
What type of risk does scientifically proven refer to?
Relative risk
What type of study are clinical trials?
Cohort study
Exposed and unexposed then count outcome events and person years
So do new treatments and standard treatment and then measure the outcomes over time
Define a clinical trial
Any for, of planned experiment which involves patients and is designed to elucidate the most appropriate method of treatment for FUTURE patients with a given medical condition
What is the purpose of a clinical trial?
To provide reliable evidence of treatment efficacy and safety
Define efficacy
The ability of a health care intervention to improve the health of a defined group under specific conditions
Define safety
The ability of a health care intervention not to harm a defined group under specific conditions
What does a Control in a clinical trial mean?
It means that there is a comparison
NOT that everything is controlled
What three things should a clinical trial be to be able to give a fair comparison of effect and safety?
Reproducible
Controlled
Fair
What does the observed rate ratio mean?
If the null hypothesis value is consistent with the observed data, then any observed difference from the null hypothesis may be due to chance
What is randomisation?
Having an equal chance of being put into group A or group B
What do non randomised clinical trials involve?
The allocation of patients receiving a new treatment to compare with a group of patients receiving the standard treatment
What are two problems with non randomised clinical trials?
Allocation bias
Confounding (known and unknown)
What is a benefit of RCT in terms of confounding?
Randomising reduces confounding
This includes confounding factors that were unknown at the time
This works as long as the sample size was large enough
What are some of the issues with the standard treatment group when using historical controls?
Selection often less well defined and less rigorous
Treated differently from new treatment group
Less information about bias and confounders
Unable to control for confounders
What factors must be controlled in a RCT?
Disease of interest Treatments to be compared Outcomes to be measured Possible bias and confounders The patients eligible for the trial The patients to be excluded from the trial
What steps are involved for conduct of the trial?
Identify a source of eligible patients
Invite eligible patients to be in the trial
Consent patients willing to be in the trial
Allocate participants to the treatments fairly
Follow up participants in identical ways
Minimise losses to follow up
Maximise compliance with treatments
How can you tell if a trial is statistically significant?
Could the observed difference have originated by chance?
Related to p value and 95% confidence interval
How can you tell whether a trial is clinically important?
How big is the observed difference between the treatment groups?
Need to have a big enough study group
Why do you need to predefine outcomes for a clinical trial?
Prevent data dredging and repeated analyses
Protocol for data collection
Agreed criteria for measurement and assessment of outcomes
What is data dredging?
Looking back at studies, at very small groups, to find an effect
What is the primary outcome used in?
Sample size calculation
What are three groups of outcomes?
Pathophysiological
Clinically defined
Patient focussed