L12- Clinical Epidemiology, Bias-Chance-Confounding

Question 1

what are the two types of error in a study

Answer 1

• random

- systematic

Question 2

what are the two types of biases in systemic error

Answer 2

• information bias: in data collection

- selection bias: in subject enrollment / participation

Question 3

what are the two types of information biases

Answer 3

• random misclassification

- non-random misclassification

Question 4

what ate the two types of non-random misclassifications

Answer 4

• recall bias

- observer bias

Question 5

define effect modification

Answer 5

• when the combination of two variables/exposures has a higher risk than then the sum of the individual risks
• implies the variables share an interaction

Question 6

define response bias

Answer 6

• anything to influence the answers to survey questions

- includes question and interviewer bias

Question 7

define Berkson’s bias

Answer 7

• idea that studies of people in hospital deals with patients of worse health and health behaviors
• therefore hospital based studies cannot be generalized to entire population

Question 8

define Pygmalion effect

Answer 8

expectations influence actions/behaviors and therefore results; whether negative or positive, it equals a self-fulfilling prophesy

Question 9

lead-time bias vs length time bias

Answer 9

Lead- earlier detection seems to lengthen survival time, although no improvement in actual disease progression

Length- slow progressive diseases are more likely to be screened than fast progressive ones, implies screening improves survival