Quiz 2 Deck 2 Flashcards
what is MDC?
Minimal Detectable Change: amount of change that just exceeds the SEM
what is MCID?
Minimal Clinically Important Difference: smallest difference in measurement that signifies an important change in pt’s condition
for outcome measurement properties that are easy to interpret, what do MDC & MCID indicate?
- below MDC = not stat significant & not important.
- btwn MDC & MCID = stat significant, but not important.
- above MCID = stat sig & important
for outcome measurement properties that are challenging to interpret, what do MDC & MCID indicate?
- below MCID = not stat significant & not important.
- btwn MCID & MDC = important change but cannot be distinguished from measurement error.
- above MDC = stat sig & important
what is pooled standard deviation
calculation of effect size for 2 groups w/in a trial
3 ways to calculate effect size for single group studies
- effect size, ES = (mean posttest - mean pretest) / SDpre
- standardized response mean, SRM = (mean post - mean pre) / SDchange
- Guyatt’s = MCID / sqrt(2 x MSE)
what does Cohen’s d interpret?
effect size & SRM between control & experimental groups
Cohen’s d criteria
- 8 = large treatment effect.
- 5 = moderate
- 2 = small
if difference in means = variance, effect size is ___
large
if difference in means > variance, effect size is ___
large
if difference in means is 50% of variance, effect size is ___
mod
effect size correlation (r)
r = d / sqrt(d^2 - 4)
experimental success rate (what it means & how to calc)
how likely the Rx group will have a successful outcome.
exp success rate = 0.5 + r/2
control success rate (what it means & how to calc)
how likely the Ctrl group will have a successful outcome.
exp success rate = 0.5 - r/2
relative success rate
= exp success rate / ctrl success rate
