Behavioral science, Psychiatry, Immunology, Pathology, Pharmacology Flashcards
What two groups are compared in a case-control study? What math is used to evaluate findings?
Group with a disease to a group without a disease. Odds ratio (prior exposure or risk factor)
What is the focus of a cohort study? What math is used to evaluate findings?
Exposure or risk (prospective or retrospective). Relative risk
Describe phase 1-4 of a clinical trial
1: Is it safe (small # of healthy volunteers)
2: Does it work (small # of patients with disease)
3: Is it better? (large #, compares to SOC/placebo)
4: Postmarketing surveillance (can it stay?)
How do PPV and NPV change with disease prevalence?
PPV increases with increasing prevalence, NPV decreases with increasing prevalence
When are prevalence and incidence the same? When is prevalence> incidence?
Prevalence and incidence are about equal in short duration disease but prevalence is greater in chronic disease
Difference in Relative risk and attributible risk?
RR is division of risk of developing disease in exposed group divided by risk of disesase in unexposed group. AR is the same variables but with subtraction
What is the equation for NNT? NNH?
NNT= 1/ARR NNH= 1/AR
Another word for accuracy? Precision?
Accuracy= validity Precision= reliability
How does an increase in precision effect the statistical power and standard deviation.
Decreases standard deviation, increases statistical power (less likely to miss a positive result)
What is Berkson bias? What type of bias is it?
Berkson bias is selection bias where the study population selected from the hospital is less healthy than the general population
What type of bias do crossover studies help to eliminate? Matching?
Both help eliminate confounding bias
What is the relation between standard deviation and standard error of the mean?
Standard error of the mean is the STDev divided by the square root of the sample size
In positive skew, where is the longer tail? Which measure is the greatest between mean, median and mode?
Longer tail is to the right and the mean is the most affected and thus greatest value
Type I vs Type II errors? What is power?
Type I:(alpha) saying there is a difference when there isn’t
Type II:(beta) saying there is no difference when there is
Power= 1-beta
What does the preset p-value usually represent?
Used to judge significance against preset alpha error value (usually 0.05)
How is power affected by increase in sample size?
Power is increased (thus Beta error is decreased)
When does the 95% CI including 0 mean something isn’t statistically significant? What about 1?
0: when mean difference is being compared
1: when odds ratio or relative risk is being compared
What is the Z score for 95% CI? 99%?
95%= 1.96 99%= 2.58 CI = mean +/- Z*SEM
How can you use the CIs of two different groups to see if a significant difference exists?
Usually, if they do not overlap the difference is significant
Four main components of informed consent.
Disclosure, understanding, capacity and voluntariness
What if a minor comes in to the ER and needs immediate blood but the parent religious/cultural beliefs are against it?
If it is emergent, give it anyway
Who typically comes first in the surrogate decision maker pathway between parents or adult children?
Adult children
What is the Tarasoff decision?
Physician is required to directly inform and protect potential victim from harm
When can an infant stand? Walk? Pincer grasp?
Stand and pincer grasp at 10 months, walk by 12-18