EBM Flashcards
The medical history of a single patient described anecdotally is known as…
Case report
‘Describes the histories of several patients with a similar problem or outcome of interest’
Case series
‘A study that uses population data instead of individual records’
Ecological study
‘The analysis of population data from a specific point in time’
Cross-sectional survey
‘People with a particular outcome are identifed and matched with controls. Retrospective analysis to identify possible causative agents’
Case-control study
‘People selected due to their exposure to a particular agent of interest. Followed up over time to track disease progress’
Cohort study
‘Each patient is randomly allocated to a group. The investigator controls the exposure of a factor of interest, and the patients followed up over time’
Randomised controlled trial
‘Compares the different responses to different treatments of individual patients for the same disease’
Crossover trial
‘Review that answers a specific pre-set question using data analysis of all related primary literature’
Systematic review
‘Statistical analysis that combines the results of multiple studies. Statistically similar studies are analysed as if they were one study”
Meta-analysis
What is the name given to the statistical value produced from a meta analysis? How is this shown?
Pooled treatment result
Forrest plot
Define validity. What are the two types of validity?
The extent to which a variable measures what its supposed to
Internal (experiemental design) and external (results application to wider population)
Define reliability…
The degree of stability when an experiment is repeated under the same conditions
A tendancy to influence trial results other than experiemental intervention is known as…
Bias
What is information bias?
Errors in measuring responses
What is selection/exclusion bias?
Based on trial recruitment
Observer bias is…
Bias if a trial co-ordinator is aware of the treatment (mitigated by blinding)
Interviewer bias is….
Weighted gathering of information
What is recall bias?
Inaccurate recollection of past events
Referer filter bias is…
When the only patients referred from primary care for trials are those with severe of atypical presentations
Confirmation bias is…
Tendency to search for information that reinforces preordained beliefs
What are confounding variables?
A variable that has an effect on the outcome yet is not the variable that researchers are interested in or aware of
What is sample variation?
The chance that different samples could provide different results within the same population
What is the true mean?
Average result if an entire population could be sampled
