Quiz 3 Flashcards
Research question
Quest for evidence
- Review study design for intervention
- Hierarchy of evidence for intervention
Study credibility
Study results
Application to the patient
Factors that influence decision on treatment
- Signs/symptoms fitting classification scheme
- Complexity of case
- Prioritize problem list
- Determine resources necessary and availability
- Identify pt educational needs
- Identify barriers to adherence
Other factors that influence tx decision
- Your past experience w these cases
- Ethical/legal/socioeconomic issues
- pt/client SES
- Pt/client preferences and values ab PT
- Relative value pt places on recovery
- Co-pay
Benefit/Risk Trade-off
If intervention is applied OR NOT, will condition improve, regress, remain same or will new problems results?
Efficacy
Extent to which an intervention produces a desired outcome under ideal conditions
Effectiveness
Extent to which an intervention produces a desired outcome under usual clinical conditions
Hierarchy of evidence for intervention
- RCTs
- Pt centered studies
- Groups of lesser quality pt centered studies
- Single lesser quality pt centered study
- Physiologic
- Case report, expert opinion, anecdote
Treatment Effect Size
How far apart are the groups
Absolute effect size
difference bw means
Standardized effect size
-includes variation in scores in the calculation
-to compare the impact of the same intervention but with different outcomes
-used to determine power calculations for minimal sample size needed to detect a statistically significant difference
Standardized effect size equation
Mean of group 1 - mean of group 2 / pooled standard deviation (value bw 0-1)
- smaller sd = bigger variation?
Effect size for clinical importance
For continuous variables:
> .8 large effect
0.5-0.8 mod effect
0.2-0.5 small effect
Absolute benefit increase (ABI)
% of people who improved in the treatment and control groups - can determine large/small tx effects
Experimental group event rate - control group event rate (a / a+b)
Relative benefit increase (RBI)
% insensitive to the magnitude of tx effects
Experimental event rate - control event rate / control event rate (c / c + d)
Absolute risk reduction
ARR = CER - EER
Absolute value of the difference in rates of adverse outcomes bw the intervention and control groups (%)
Relative risk reduction
RRR = CER - EER / CER
Absolute value of the rate of decrease in adverse outcomes bw the intervention and control groups (%)
P value
Describe the magnitude of the group difference that is greater than chance (>.5)
Confidence intervals
More helpful in determining meaningfulness of the study findings or the precision of the effect size (ABI,RBI,ARR,RRR). Can be negative value. Narrow ci with minimal bias and strong stat significance should be taken seriously.
MCID
Smallest tx effect that would be meaningful to pt and pt management, fewest side effects, lowest cost and least inconvenient. Not necessarily clinically important.
Number needed to treat (NNT)
NNT = desired outcome in experimental / desired outcome in control. Applies to group of pts only.
Nomograms
Like likelihood, outcome on left then draw through RRR to find NNT.
