AAAA Therapy Flashcards
Objectives:
❖Introduce a framework for using population based research in clinical practice (Assess-Access-Appraise-Act)
❖Rehearse the framework for a question about the effectiveness of a treatment
❖Understand key methodological aspects of studies used to evaluate effectiveness of a treatment
❖Calculate and interpret common ‘effectiveness’ outcome measures
What are the 4 elements of the aaaa framework
❖Assess: what type of healthcare question – what type of study?
❖Access: finding the ‘best’ evidence (validity/ trustworthy and relevance)
❖Appraise: evaluating the quality of the evidence & interpreting the results
❖Act: is this evidence relevant to my clinical practice. Should this evidence change my practice?
Why is aaaa important
❖An essential professional and academic skill
❖Medical knowledge is continually evolving.
❖The medical profession frequently fails to use effective treatments even when they are available.
❖Keeping up to date is a lifelong commitment for every doctor.
❖You need to develop and use the skills to find, appraise and act on research evidence.
What is evaluation bypass
Avoid evaluation bypass
Where interventions adopted with unevaluated procedure
With only enthusiasm, convictions, and commercial pressure
And no good evidence
Example of RCT which was planned to address gap in evidence
❖Corticosteroids had been used to treat acute head injury for more than 30 years
❖MRC-CRASH Randomised Controlled Trial aimed to solve remaining uncertainty of benefit
❖International trial n=20,000 planned
❖Trial stopped early (n=10,000) – evidence of harm
❖Mortality at 2 weeks -21.1% with steroids -17.9% with placebo
❖Hundreds of thousands harmed (killed) internationally
What study design is used for a effectiveness question
RCT
Cause and effect their is a hierarchy of evidence. Three key characteristics that determine validity of study:
Casual agent - treatment
Effect - benefit to patient
- Temporality - whether cause proceeds the outcome. RCT and cohort studies high in hierarchy
- Experimental evidence - RCT less biased than observational studies
- Evidence from several studies rather than one - systematic reviews are best
What to do when assessing clinical question
- Effectiveness is a balance btw benefits and harm
- Potential side effects
What are clinical components of an effectiveness question
❖Population: those who are eligible for treatment with the intervention / comparator
❖Intervention: New treatment
❖Comparator: Existing treatment / usual care (may be no
treatment)
❖Outcome(s): Mortality / morbidity / physiological measure (BP)
Formulating PICO is important for:
• Efficient searching for evidence in electronic bibliographic databases such as MEDLINE
• Assessment of the applicability of research to your patients
What is access in the framework
How to find the best study
That are clinically relevant to the question
How to access specific RCTs
❖Use the components of your question-specific PICO
❖Start with terms for Intervention of interest. If necessary to increase
specificity of the search combine with terms for the Population
❖Often more than one one term to describe question components which can be taken from:
-bibliographic database thesaurus’ (MEdical Subject Headings) -non MESH terms for the question component (free Text
terms)
What are Boolean operators
❖Combine terms using Boolean operators:
-“AND” gives search results which include both search terms
-“OR” gives search results which include either one or other or both search terms
What is appraise in the framework
Quality of the conduct of the study
Interpretation of the results
❖Does the study address a research question which is relevant to my clinical problem
(is there a match between my PICO & the study question?)
❖Did reserchers use the study design most likely to provide a valid answer to the clinical question
(for effectiveness was it an RCT?)
❖Was the study done well / is the study trustworthy ? (were steps taken to reduce bias?)
❖If the study was done well (valid), what were the results?
(direction, size, precision and statistical significance of results)
What is bias
If pattern of deviation has a systematic pattern
Key Features of an RCT
Prospective
Exposure (treatment) comes before we measure the outcome
New treatments/ comparator
Randomisation
Why do we have a control group
Having a control group allows us to evaluate whether patients would get better anyway - the comparator treatment /no treatment
Why do drug manufactures not allocate treatment
Patients have different abilities to benefit from treatment
Manufacturer may be inclined to select patients with a better prognosis to have new treatment
May make new treatment look better than actually is
Removes selection bias
Why cant patient/ dr allocate treatment
Patients and doctor may choose for more severe patients to receive the new treatment
Skews the results and data
Imbalance between group with treatment and control
So removes selection bias