Strand B Flashcards
What is a clinical trial?
A research study in which one or more human subjects are prospectively assigned to one or more interventions to evaluate those interventions on health-related biomedical or behavioural outcomes
What is a clinical study?
A study involving using human volunteers that is intended to add medical knowledge, interventional and observational
What is the difference between a clinical trial and study?
Study - interventional and observational
Trial - interventional only
What is the history of clinical trials?
562 BCE - ‘first’ clinical trial
1537 - first trial of 2 medical treatments
1747 - one of the earliest controlled clinical trials
1940s - first double blind clinical trial
1948 - first ‘true’ randomised control trial
What are the different types of clinical trials?
Mechanistic
Exploratory/development
Pilot/feasibility
Other interventional
Behavioural
Basic experimental (BESH)
What are the differences between experimental and observational studies?
Experimental - Randomised control trials (RCTs)
Non-randomised control trials (nRCTs)
Observational - Cohort studies
Case-control studies
Cross-sectional studies
Ecological studies
What are randomised control studies (RCTs)?
Used to find effectiveness of new treatment while eliminating as many biases as possible
Randomised to one of two or more groups to test specific drug, treatment, etc (e.g. intervention used vs placebo)
Groups are followed up to see how effective
Outcomes measured at specific times and different responses are assessed statistically
What are non-randomised control studies (nRCTs)?
People allocated to different interventions using methods that are not random
Purely observational, non-randomised interventional studies, and single-arm trials with external control
What are cohort studies?
Observational study using defined groups while being followed over time
People with similar characteristics
Why are cohort studies used?
Examine associations between different interventions received and subsequent outcomes
What is the difference between a prospective and retrospective cohort study?
Prospective - recruits participants before
Retrospective - subjects from past records describing interventions received
What are case-control studies?
Observational study to find the possible cause of a disease/condition
Researcher looks for aspects of lives that differ to see what has caused the condition
Why are case-controlled studies used?
Compares groups of patients who have the disease with a group of people without but with similar characteristics (unrelated from condition)
What is a cross-sectional study?
A ‘snap-shot’ observation of a set of people at 1 time
Describe a variable not measuring it
Why are cross-sectional studies used?
Public health research uses this to assess exposure and a disease and compare the rates of disease and symptoms of an exposed and unexposed group
What are the advantages and disadvantages of cross-sectional studies?
Advantages: cheap, quick, minimal room for error
Disadvantages: Doesn’t help determine cause and effect, report bias is probable (surveys)
What are ecological studies?
Used to understand relationship between outcome and exposure at a population level (population with shared characteristics)
Characteristics include geography, ethnicity, socio-economic status of employment
Why are ecological studies used?
Ecological vs other studies is the group is the unit analysis studied no assumptions about individual study participants
What are the phases of a clinical trial?
Laboratory studies - cell/animal studies
Phase I - Safety of medication on people
Phase II - Safety and effectiveness
Phase III - Safety, effectiveness and dosing
Phase IV - long-term effectiveness vs new treatment to standard treatment
What happens during the laboratory stage of clinical trials?
Basic research, accurately model desired biological effect of a drug predicting treatment outcome in patients and predict ant adverse reactions
Testing: in vitro, in vivo and drug profiling using computer models
What happens during phase I of clinical trials?
Drug/treatment on small group of people for first time
Safety and side effects
Several months
Success around 52%
What happens during phase II of clinical trials?
Larger group of people
Emphasis on effectiveness
Preliminary data whether drug works in people with disease/condition
Last several years (~1-4)
Success around 30%
What happens during phase III of clinical trials?
Large groups of people
More information of safety and effectiveness, different populations and dosages and drug-drug interaction
Information for the drug to be used safely
Success around 58%
What is the FDA approval stage during clinical trials?
New Drug Application (NDA) for treatment to an organisation e.g. FDA
Review results to determine if approves the drug and allow marketing to public
Continue to monitor effects
Success around 25-30%