Flashcards in Behavioral Science - UWorld Deck (18)

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1

## A payer pays a fixed predetermined fee for all healthcare services required by a patient

### Capitation. This is the concept behind HMOs.

2

## 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

3

## Attrition bias

### Study subjects are assigned to groups in a non-random fashion

4

## 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

5

## 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.

6

## Type I error

### Reject the null when it's actually true...i.e. say there is a difference when there's truly not.

7

## Odds ratio

### AD/BC. Only use in case-control studies because you do not follow patients over time and cannot assess risk.

8

## 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.

9

## Relative risk

### [a/(a+b)] / [c/(c+d)]

10

## 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.

11

## Absolute risk reduction

### Event rate in control group - Event rate in treatment group

12

## Relative risk reduction

### Absolute relative risk / control rate.

13

## Number needed to treat

### 1/Absolute risk reduction or 1/(control rate - treatment rate)

14

## When does the OR approach RR?

### When disease incidence is low

15

## Number needed to harm

### 1/Attributable Risk (treatment group event rate - control group event rate)

16

## Benzo with short t1/2 that can be used for short-term insomnia treatment in patients that cannot tolerate daytime sleepiness

### Triazolam

17

## Attributable risk percent

###
100 x [(exposed risk) - (unexposed risk)]/exposed risk

or more simply

100 x (RR - 1)/RR

18