H&S Formative Feedback Flashcards
What are the features that make an RCT beneficial?
Placebo arm ensures any effect is attributable to the intervention alone.
Random allocation because it ensures no selection bias and that confounding factors are evenly distributed
What does it mean if the confidence intervals between studies overlap?
There is no statistically significant difference between the groups.
What are the features of trials translated to English?
Larger effect size, therefore only including English trials will lead to overestimation of effect.
Why is assessing the quality of the included studies important in systematic review?
Quality of the stud insures that the effect estimate is not over-estimated. Pre-agreed criteria maes sure that the process of systematic review is objective and transparent.
Meta analysis definition?
STATISTICAL COMBINATION of the results of multiple studies into a SUMMARY ESTIMATE.
What is the confidence interval indicate?
Range of values where the true mean is likely to lie, therefore a value which is within the interval provides evidence to reject the null hypothesis and that it is statistically significant.
What is deductive reasoning?
Generating a specific argument because it is logically conclusive support for the conclusion.
What is inductive reasoning?
Based on a body of observations that makes a generalised conclusion for a probable conclusion.
What makes an argument invalid?
It is possible for the premises to be true however this will not change that the conclusion will be false.
How is the quality of evidence assessed in systematic reviews?
Using GRADE, which rates the certainty and validity of evidence in systematic reviews and meta-analysis.
What should be considered when doing a conclusion of results of meta-analysis?
If the intervention can be offered in the local setting
All important outcomes were considered from the perspective of the patient/family/policymakers
Any bias in the studies
Confidence intervals and whether they overlap with line of null effect
The pooled effect estimate lies within the CI and if this overlaps with the line of null effect
Rejection or accepting the null hypothesis
What is the CASP checklist?
Checklist of prompt questions for evaluation of research studies like RCT’s and systematic review. These are structured around 3 main sections:
Are the results valid?
What are the results?
Can these be applied in local settings
What is expectation bias?
Observers report or analyse data in line with what they think is likely to happen, which only occurs in non-blinded trials.
What is publication bias?
Failure to publish results from valid studies, often as they showed a negative or uninteresting result. Important in meta-analyses where studies showing negative results may be excluded.
What is expectation bias?
Only a problem in non-blinded trials. Observers may subconsciously measure or report data in a way that favours the expected study outcome.
What is power in a study?
Probability of identifying a statistically significant difference and correctly rejecting the null hypothesis when it is false, which is used to identify the true effectiveness of an intervention.
What is p value?
The probability of obtaining the observed results if the null hypothesis is true, in order to determine if the result is statistically significant. Therefore a p value of 0.03 means there is a 3% chance of the results occurring if the null hypothesis is true.
