Quiz 3 Flashcards
It is well documented that patients’ response to pain medication is associated with their hair color. Specifically, patients with red hair require a higher dose of anesthesia than brunettes or blondes to achieve equivalent pain relief. I conducted a randomized controlled trial on dental anxiety during tooth extraction, and determined, after the fact, that 10% of one group was redheaded, while 30% of the other group was redheaded. What should I be concerned about when interpreting the results of my study?
Threats of maturation & history
Statistical validity
Inclusion and exclusion criteria
External validity
Internal validity
internal validity
If I can show that the independent variable (and only the independent variable) caused the difference in my dependent variable across groups, I have established good:
External validity
Internal validity
Statistical validity
Power
internal validity
You are interested in determining if yoga can help improve (ie, reduce) stress.
You enroll participants in a study in which they practice yoga every day in a group setting for 10 days. You measure the participant’s stress level on Day 1 and Day 10, and note that, on average, they report lower stress on Day 10 than Day 1. What can you conclude about the efficacy of yoga in reducing stress?
It relieves stress
It enhances stress
Nothing
Gathering in a group reduces stress
nothing
Regarding the yoga study above, how could you improve its design?
Ask the participants if they thought the yoga helped their stress
Randomize the yoga positions
Make the yoga sessions harder
Recruit people who gather as a group, but do not do yoga
recruit people who gather as a group, but do not do yoga
A health care provider advertises that she is able to reduce low back pain. In order to support her claim, she enrolls 30 new patients in her pain reduction program. She measures their back pain on Day 1, and again on Day 30. Average back pain is shown to decrease significantly. What can she legitimately claim about the efficacy of her back pain reduction program, and which threat to validity is most salient?
Nothing, history
Nothing, maturation
Efficacy, statistical
Efficacy, regression to the mean
Efficacy, instrumentation effects
nothing, maturation
You are just beginning a new line of research, and it is very important that you determine that your new therapy is more effective than standard of care, if in fact, this is the case. What type of study will you design?
Effectiveness study
Efficacy study
A study with statistical validity
A study that is externally valid
efficacy study
I recruited subjects from one large apartment complex to participate in a study. I assigned one-half to an active exercise program, and the other continue their routine exercise program. Early in the study, the apartment complex opened a new gym free to its residents. What threat to validity is most likely to come into play?
Maturation
Practice
History
Setting
Bias
hx
I have recruited 60 patients to be in my study, and assigned 30 patients randomly to each of two groups. The therapy I am testing takes six seeks to complete. Three patients drop out of my placebo group and 10 drop out of my active group before completing therapy. I should be concerned, most, about the threat to:
External validity
History
Internal validity
Maturation
None of the above
internal validity
Social Psychology reports have been impugned as creating a, “psychology of college freshmen” because most of their subjects were students taking Psychology 101 who were given course credit for participating in their professors’ research. If pressed, what concern would critics cite?
external validity
Randomized controlled trials are highly valued because they address issues concerning:
Both intrinsic and extraneous variables
Extraneous variables
Intrinsic variables
External validity
both
A crossover design requires all subjects to participate in:
All levels of the intervention simultaneously
The control level of the intervention more than once
All arms (interventions) in a study
The active level of the intervention more than once
All arms (interventions) in a study
A quasi-experimental study does not include
Participants
Randomization
Dependent variables
Variable operationalization
randomization
In single-group designs, the independent variable is:
The same as the dependent variable
Time
Undefined
Group assignment
time
In a single-subject design, subjects should not be switched to the next phase until
Stability in the outcome measure is achieved
The subject indicates he is exhausted
The subject achieves the highest score possible
The subject’s score is substantially different from the previous trial
Stability in the outcome measure is achieved
the internal validity of a single-subject design will increase with the
Passage of time
Number of subjects
Number of phases
Rapidity of phase shifts
number of phases
A crossover design may not be used if:
The response score does not achieve stability
Fewer than 30 subjects are enrolled
An efficacy design is required for the study
The intervention being tested has long-lasting effects
The intervention being tested has long-lasting effects
