biostats mod 7,8,9

Question 1

def. relative risk

Answer 1

RR is the risk of disease in an exposed population due to exposure relative to unexposed population

Question 2

RR formula

Answer 2

incidence in exposed/incidence in non-exposed

a/a+b)/(c/c+d

Question 3

how to interpret RR

Answer 3

less than 1 = less incidence

more than 1 = more incidence

Question 4

how is RR diff. from chi

Answer 4

RR - gives magnitidue of diff. between rates

chi - tells you whether these numbers were likely due to chance

Question 5

def. odds ratio

Answer 5

OR = odds of a person with disease being exposed vs. not exposed compared to a person without the disease being exposed vs. not exposed

Question 6

what is OR limit

Answer 6

relative risk generally preferred - as the prevalence increase the OR becomes a poor approximation of relative risk

Question 7

OR formula

Answer 7

odds of exposure given event/odds of exposure given no event = ad/bc

Question 8

how to interpret OR

Answer 8

OR1 = higher risk of outcome from exposure

Question 9

what is slope in regresson

Answer 9

estimate of the changes in the outcome associated with a one unit change of IV

Question 10

5 main steps to data interpretaion

Answer 10

1. do data tables etc. match up to plan
2. answer primary RQ
3. answer secondary questions
4. put it all together as a whole
5. criticize work

Question 11

def. prevalence

Answer 11

of affected indivs/total pop

Question 12

sens

Answer 12

TP/TP+FN

Question 13

spec

Answer 13

TN/TN+FP

Question 14

PPV

Answer 14

TP/TP+FP

Question 15

NPV

Answer 15

TN/TN+FN