research

Question 1

formula for sensitivity

Answer 1

TP/(TP+FN)

testing for true positive
good screener- good at ruling out

Question 2

formula for specificity

Answer 2

TN/(TN+FP)

testing for true negative
good at confirming- rule in

Question 3

formula for PPV

Answer 3

TP/(TP+FP)

someone having the disease actually testing positive for it

Question 4

formula for NPV

Answer 4

TN/(TN+FN)

someone healthy actually testing negative for it

Question 5

NNT formula

Answer 5

1/absolute risk reduction

Question 6

how is PPV and NPV related to prevalence

Answer 6

greater the prevalence the higher the PPV

less the prevalence the higher the NPV

Question 7

at what p value does it indicate a statistically significant result

Answer 7

p < 0.05 is statistically significant to reject the null hypothesis
this means there is a 5% likelihood that your results are just d/t chance

Question 8

what is a type I error

Answer 8

rejecting the null hypothesis in error

same as the P value

Question 9

what is a type II error

Answer 9

accepting the null hypothesis in error

Question 10

what is validity

Answer 10

whether and instrument or test actually measured what it is support to measure

think ear thermometer

Question 11

what is reliability

Answer 11

the consistency of reults

Question 12

intention to treat

Answer 12

analysis that insists that all pts remain in the original groups they were initially randomly assigned in the study

helps increase the power of a study

Question 13

what is NNT

Answer 13

number of pts you would need to tx to prevent one additional adverse affect

Question 14

what is incidence

Answer 14

number of newly dx cases

Question 15

what is prevalence

Answer 15

number of total cases in a population

Question 16

what is standard error

Answer 16

the accuracy of the sample mean in comparison to the true population mean

for example— determine average height in 10 y/o girls ned a sample with rage of heights that are representative of the general population

Question 17

what is pre test probability

Answer 17

the estimate of the probability of a condition present before you do testing

think about criteria/guidelines before testing is done (ie centaurs criteria before rapid strep)

Question 18

likelihood ratio

Answer 18

a person with the disease will have a positive test result

LR greater than 1 increases the probability that the target condition is present
LR less than 1 makes the condition less likely

Question 19

formula for absolute risk

Answer 19

a/(a+b)

a= exposed + disease
b= exposed + healthy

Question 20

formula for relative risk

Answer 20

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

a= exposed + disease
b= exposed + healthy
c= not exposed + disease
d= not exposed + healthy

Question 21

formula for odds ratio

Answer 21

(a/(a+b))/(b/(a+b)) or a/b

a= exposed + disease
b= exposed + healthy

Question 22

what is the best type of scientific study

Answer 22

RCT

gold standard of research design

Question 23

what is a cohort study?

Answer 23

cohort is followed forward or traced backwards to investigate associated risks for a certain outcome

need a large sample size

Question 24

what is the difference in case control and cohort studies

Answer 24

cohort uses a large sample size to evaluated associated risks and outcome
case control uses a small sample size of individuals with disease (case) compared to a control and then check back for risk factors

Question 25

what is a cross sectional study

Answer 25

observation and looks at association between 2 measured factors at one point in time

a “snap shot”