Interventions Flashcards
How can systematic reviews and meta-analyses still be misleading?
if the evidence included in the analyses is of low quality
What is used to compare different interventions?
Effect sizes
what do effect sizes show?
provide the difference in improvement between intervention and the control group, adjusted to the scale and accuracy of the measurements used in each study
how are effect sizes adjusted?
commonly the standardised mean difference in the measure used
what is the unit for effect size?
Cohens D
what is selection bias?
when there is a difference between the control and treatment groups that are being compared (difference is there before the study starts)wh
what is performance bias?
difference between groups in the care that is providedw
what is detection bias?
difference between groups in how outcomes are determined
what is attrition bias?
differences between groups due to withdrawal from a study, either due to exclusions or attrition
what is reporting bias?
differences between reported and unreported findings (significant findings more likely to be reported)
how could you control for selection bias?
randomisation of assignment to condition groups - ensuring there is controls where the treatment condition is as similar to the control group as possible
how can you control for performance bias?
double-blinding
how can you control for detection bias?
outcome assessor blinding
how can you control for reporting bias?
pre-specified outcome measures
