Biostatistics Flashcards
What is the only type of study that can provide information about absolute risk?
Cohort
Composition of group in Phase I clinical trial?
Healthy volunteers
Composition of group in Phase II clinical trial?
Patients
Composition of group in Phase III clinical trial?
Patients vs. Controls
___ Bias refers occurs when focusing of subgroup for study
Sampling
___ Bias refers occurs when dividing subjecting into experiment + control groups
Selection
Solution for Selection Bias?
Randomization
Who is subject to Recall Bias?
Patients
Solution for Recall Bias?
Blinding
Who is subject to Observer Bias?
Researchers
Solution for Observer Bias?
Blinding
Incidence is a measure of …
Risk
Equation for Relative Risk?
[(A/A+B)] / [(C/C+D)]
Equation for Attributable Risk?
[(A/A+B)] – [(C/C+D)]
Equation for Odds Ratio?
AD / BC
Relationship between Power and Type II error?
P = 1 – β … (β = Type II error) … Increase power, Decrease Type II error
Diagnostic test has SN = 0.75, SP = 0.9; Prevalence of disease = 0.10 – what is the PPV of the test?
45% … start with N = 1000; plug in prevalence, then SN/SP
Prevalence of disease = 20%; Diagnostic test has SN = 95%, SP = 50% – what percent of group who tests (+) will actually have confirmed disease?
32%
Equation for RRR?
(CER – EER) / CER … CER = Control Event Rate; EER = Experimental Event Rate
Equation for ARR?
(CER – EER) … CER = Control Event Rate; EER = Experimental Event Rate
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?
1/0.1 = 10
