Flashcards in Behavioral Science - UWorld Deck (18)
A payer pays a fixed predetermined fee for all healthcare services required by a patient
Capitation. This is the concept behind HMOs.
Positively vs. negatively skewed Bell curve
Positively skewed = most scores are on the lower end and mean > median > mode
Negatively skewed = most scores are on the high end and mode > median > mean
Study subjects are assigned to groups in a non-random fashion
Cancers with highest incidence/mortality in US men and women
Men incidence: prostate > lung > colon
Men mortality: lung > prostate > colon
Women incidence: breast > lung > colon
Women mortality: lung > breast > colon
Study's ability to detect a difference when one exists
Power = 1 - beta, where beta = the likelihood of making a type II error (accepting the null when it's actually false...i.e. say there isn't a difference when there truly is). Thus, power is the likelihood of rejecting the null when there really is a difference.
Type I error
Reject the null when it's actually true...i.e. say there is a difference when there's truly not.
AD/BC. Only use in case-control studies because you do not follow patients over time and cannot assess risk.
A new study is developed for prostate cancer that is negative in 95% of patients who do not have cancer. If the test is used on 8 blood samples from patients without prostate cancer, what is the probability of getting one false-positive result?
The probability that one sample tests positive = 1 - (0.95^8) because you are testing the probability of a series of independent events, which requires mulitplication of the probability of each individual event.
[a/(a+b)] / [c/(c+d)]
How do you relate carrier, disease and gene frequency for an autosomal recessive disease with only two possible alleles?
Hardy-Weinberg Principle: p^2 + 2pq + q^2 = 1
-p = homozygous dominant individuals
-2pq = carrier frequency
-q = homozygous recessive individuals (q^2 = disease frequency for autosomal recessive diseases)
***It is important to remember that you only need one value, p or q, and then you can calculate the frequency because there are only two alleles for the disease. Plug your known value into the Hardy-Weinberg equation, then substitute that value for (p+q)=1 and solve for the other variable, then plug it back into the Hardy-Weinberg Principle and it will give you that genotype frequency in the general population.
Absolute risk reduction
Event rate in control group - Event rate in treatment group
Relative risk reduction
Absolute relative risk / control rate.
Number needed to treat
1/Absolute risk reduction or 1/(control rate - treatment rate)
When does the OR approach RR?
When disease incidence is low
Number needed to harm
1/Attributable Risk (treatment group event rate - control group event rate)
Benzo with short t1/2 that can be used for short-term insomnia treatment in patients that cannot tolerate daytime sleepiness
Attributable risk percent
100 x [(exposed risk) - (unexposed risk)]/exposed risk
or more simply
100 x (RR - 1)/RR