bioethics/biostats

Question 1

external relationship obscures the relationship being studied
- ex: smokers consuming more alcohol than non-smokers obscures the relationship between smokers and hepatic carcinoma

Answer 1

confounding bias

Question 2

investigator inadvertently influences the subjects in order to guide the results in a previously expected direction
- subjects perform better when there are positive expectations and perform less well when the expectations are low

Answer 2

experimenter-expectancy bias

- aka observer–expectancy bias or the Pygmalion effect

Question 3

study sample does not reflect the general population

Answer 3

selection bias

Question 4

false estimations of survival rates due to the disease being diagnosed at an earlier stage

Answer 4

lead-time bias

Question 5

TP / (TP + FN)

Answer 5

sensitivity

- ability to detect the disease

Question 6

TN / ( TN + FP)

Answer 6

specificity

- ability to detect the absence of disease

Question 7

information was gathered at an inappropriate time, causing results to be skewed
- ex: study of fatal disease, only survivors are alive to answer questions, opinions of deceased not taken into account

Answer 7

late-look bias

Question 8

when information is gathered in a systematically distorted manner

Answer 8

measurement bias

Question 9

how likely that a patient is healthy (does NOT have disease)

Answer 9

negative predictive value

Question 10

(A/C) / (B/D)

Answer 10

odds ratio

Question 11

what type of error occurs if the null hypothesis is not rejected even though it is false; i.e., indicating that there is NO relationship between groups when one actually exists in the population

Answer 11

type II
- occurs when there is low statistical power. Increasing the size or reducing the variability of the study groups increases statistical power, thus decreasing the probability of a type II error

Question 12

measures the number of new cases in a population over a specified period of time

Answer 12

incidence

Question 13

measures the total number of cases (new cases + existing cases) in a population during a period of time or at a specific point in time

Answer 13

prevalence

Question 14

comparing a group of people with a certain disease, to a group of people without the disease

Answer 14

case-control

Question 15

comparing risk factors (and lack of said factors) within a group of people with a specific disease
- both groups have disease, some are exposed to a risk factor, some are not

Answer 15

cohort

Question 16

[TP / (TP + FP)] / [FN / (FN + TN)]

Answer 16

relative risk

= (incidence of the exposed group) / (incidence of the unexposed group)

Question 17

when a study reports that there IS a relationship between two factors, when, in fact, none exists

Answer 17

type I error

Question 18

test that checks the difference between means of two groups

- ex: comparing mean BP between men and women

Answer 18

t-test

- T is meant for two

Question 19

test that checks differences between means of 3 or more groups
- ex: comparing the means blood pressure between members of 3 different ethnic groups

Answer 19

ANOVA

- 3 words: analysis of variance

Question 20

test that checks differences between 2 or more percentages or proportions of categorical outcomes (not mean values)
- comparing the percentage of members of 3 different ethnic groups who have essential HTN

Answer 20

Chi-square test

- “chi”-tegorical

Question 21

test that checks the differences between 2 percentages or proportions of categorical, nominal outcomes (small groups)
- comparing the percentage of 20 men and 20 women with HTN

Answer 21

Fisher’s exact test

Question 22

what are the only 2 mature defense mechanisms?

Answer 22

1. sublimation: channeling impulses into socially acceptable behavior
2. suppression: putting unwanted feelings aside to cope with reality

Question 23

what is splitting?

Answer 23

black and white

- experiencing a person/situation as all positive or all negative