Exam Two - RCT Part One Flashcards
RCTs are the gold standard for…
showing cause and effect
RCTs typically have high _________ validity
internal
what are 3 things we should consider in order to be critical consumers of RCTs?
1 - importance/clinical relevance (size of effect)
2 - generalizability
3 - internal validity (PEDro)
What levels of evidence are RCTs?
1b or 2b
t or f, authors are always truthful and transparent when reporting research findings
false, they can fudge details and exaggerate results to bias readers
(trial design, conduct, analysis/interpretation)
what was the goal of the CONSORT statement
CONsolidated Standards of Reporting Trials
- increase transparency of important aspects of the trail (so reader can interpret internal validity for themselves)
What is the purpose of the flow diagram
depict the passage of participants through a RCT (did any people drop out, if so, why?)
What are the 4 stages of an RCT where you have to report sample size
1 - enrollment
2 - allocation
3 - follow-up
4 - analysis
what are the two questions you must answer at each stage about sample size?
1 - number of participants for each group
2 - reason for loss or removal
what are some common explanations for loss of subject data
- drop outs during intervention
- refusal of assigned treatment
- lack of compliance
why is missing data a big deal?
threatens internal validity
what are two common ways to handle missing data for analysis
1 - completer analysis
2 - intention to treat analysis
completer analysis
- exclude missing data
- analyze ONLY the results of subjects who complied with the study protocol
intention to treat analysis
- include missing data
- data analyzed according to the initial random assignments regardless of the treatment they actually received
pros of completer analysis
- demonstrates the effect of a treatment if the patient is compliance
cons of complete analysis
disregards the results of patients who dropout
- sub. perceive gain will probs stay and those that don’t will probs leave
unequal group numbers at the end of the study
- increase likelihood of certain stats assumptions being violated
completer analysis use may be justified if….
the number of missing cases is small and RANDOM cases are missing
“last observation carried forward” means…
the last know data point is used for the final outcome for the subject (used in ITT analysis)
ITT analysis protects….
sample size calculation and similar group sizes
T or F, if you use completer analysis you’ll get a PEDro point
false, you will get a point if you use ITT analysis
How is ITT analysis considered to reflect clinical practice
- some patients are noncompliant
- answers “how will this treatment work for me if it is applied in a similar clinical environment”
ITT analysis is believed to guard against the potential for bias if…
dropouts are related to outcomes or group assignment
ITT analysis may bias the results towards an effect if:
many people dropout from the control group but their treatment IS effective
ITT analysis may bias the results toward no effect if:
many people dropout from the treatment group but their treatment IS effective
Why do most current recommendations say use ITT analysis not completer?
because is more closely resembles clinical practice
Many papers report ____ completer and ITT analysis
both
Dr. WIllson thinks this is BEST research practice
