EIDM Flashcards
What are three qs to ask when looking at a study?
1) Does the study answer my practice question?
2) Are the results of the study valid? (minimizes bias, results not due to other factrors, results can be applied to larger population, outcomes analyzed)
3) Can I apply these results to my nursing practice?
What are intervention studies?
- address a treatment/therapy or prevention
- RCT is the strongest design
- determine how the interventions affects the outcome
- RCT not always ethical, observational studies can be used
What observational studies exist?
- cohort analytic study (one group, before and after)
- case control study
How can participants be selected for an intervention study?
- convenience sampling (volunteer); potential bias, making results less valid
- random sampling (ideal)
- better if allocation can be concealed
What is allocation sequence?
- random process of allocating participants into experimental/control groups
What is allocation concealment?
- researchers not aware of how allocation occurred, unpredictable (remote randomization, opaque envelopes, medications look similar)
- participants blinded to what group they are in
- prevents bias
How do we know whether randomization of participants occurred?
- compare experimental and control groups - similar in all known determinants of the outcome
- usually uses p-value to compare the two groups
- assume unknown determinants corrected with randomization
Where could potential biases occur without blinding?
- participants if they know what group they are in (Hawthorne effect)
- people delivering the intervention could make intervention look more effective
- people evaluating the outcome
What is intention-to-treat analysis?
- outcome analysis should include the participants who dropped out before completion of the study within the group they were originally allocated
- statistical analysis needs to include all participants, even those not completing the study
What should we ask about follow-up?
- was it complete and was it long-enough?
- were all participants accounted for?
What are the two types of variables?
1) dichotomous (yes/no)
2) continuous
What are the types of continuous data?
- ordinal: sets of ordered categories (pain scale)
- interval: ordered set where series of intervals are the same size (temperature)
- ratio: interval with absolute 0 (weight)
- can be reported as dichotomous data but not vice versa
How is treatment effect measured for continuous data?
- uses “mean” values to show whether data changed after exposure to intervention
- may include the range of values and/or standard deviation (variable around the mean)
- line of no difference is 0
How is treatment effect measured for dichotomous data?
- line of no difference is 1
- outcomes reported as relative risk (RR) or odds ratio (OR)
- RR or OR = 1 means there is no difference between the control and intervention group results
- RR or OR > 1 means more of the outcome in the intervention group (less in the control group)
- RR or OR < 1 there is less of the outcome in the intervention group (more in the control group)
What is OR/RR?
The odds or risk that an outcome will occur in the intervention group compared to the control group