Biostatistics

Question 1

What is the only type of study that can provide information about absolute risk?

Answer 1

Cohort

Question 2

Composition of group in Phase I clinical trial?

Answer 2

Healthy volunteers

Question 3

Composition of group in Phase II clinical trial?

Answer 3

Patients

Question 4

Composition of group in Phase III clinical trial?

Answer 4

Patients vs. Controls

Question 5

___ Bias refers occurs when focusing of subgroup for study

Answer 5

Sampling

Question 6

___ Bias refers occurs when dividing subjecting into experiment + control groups

Answer 6

Selection

Question 7

Solution for Selection Bias?

Answer 7

Randomization

Question 8

Who is subject to Recall Bias?

Answer 8

Patients

Question 9

Solution for Recall Bias?

Answer 9

Blinding

Question 10

Who is subject to Observer Bias?

Answer 10

Researchers

Question 11

Solution for Observer Bias?

Answer 11

Blinding

Question 12

Incidence is a measure of …

Answer 12

Risk

Question 13

Equation for Relative Risk?

Answer 13

[(A/A+B)] / [(C/C+D)]

Question 14

Equation for Attributable Risk?

Answer 14

[(A/A+B)] – [(C/C+D)]

Question 15

Equation for Odds Ratio?

Answer 15

AD / BC

Question 16

Relationship between Power and Type II error?

Answer 16

P = 1 – β … (β = Type II error) … Increase power, Decrease Type II error

Question 17

Diagnostic test has SN = 0.75, SP = 0.9; Prevalence of disease = 0.10 – what is the PPV of the test?

Answer 17

45% … start with N = 1000; plug in prevalence, then SN/SP

Question 18

Prevalence of disease = 20%; Diagnostic test has SN = 95%, SP = 50% – what percent of group who tests (+) will actually have confirmed disease?

Answer 18

32%

Question 19

Equation for RRR?

Answer 19

(CER – EER) / CER … CER = Control Event Rate; EER = Experimental Event Rate

Question 20

Equation for ARR?

Answer 20

(CER – EER) … CER = Control Event Rate; EER = Experimental Event Rate

Question 21

New hormone therapy developed for women who are at risk of osteoporotic fractures; 15% of women in control group develop fracture; 5% of women in treatment group develop fracture – what is NNT?

Answer 21

1/0.1 = 10