Behavioral Science/Stats Flashcards
Study type that establishes prevalence
Cross-sectional
Case-control study measure?
Odds ratio (What was “odd” about their history?)
Case-control study design?
People with disease v. people without disease. Looking for prior exposure or a RF
Cohort study measure?
Relative risk (Increased risk for disease)
Cohort study design?
People with exposure v. people without exposure
Twin concordance study design?
Frequency of disease between twins
Pharm phase I asks?
Is it safe? Safety, toxicity, pharmacokinetics
Pharm phase II asks?
Does it work? Efficacy, dosing, AE’s
Pharm phase III asks?
Is it as good or better?
Pharm phase IV asks?
Can it stay? Post-marketing surveillance
Sensitivity =
TP / (TP + FN) = Pr (T+|D+)
Specificity =
TN / (TN + FP) = Pr (T-|D-)
PPV =
Pr (D+|T+) = TP / (TP + FP)
NPV =
Pr (D-|T-) = TN / (TN + FN)
Prevalence is related to incidence how?
Prevalence is approx incidence rate x avg disease duration
Incidence rate =
of new cases in specified time period / population at risk during same time period
Odds and Probability related how?
Odds = Pr / (1-Pr) ; Pr = O / (1 + O)
What parameters are only dependent on the test itself?
Sensitivity, specificity, likelihood ratio
Odds ratio and relative risk?
OR = (a/b) / (c/d) = ad/bc; RR = [a / (a+b)] / [c (c+d)]
RRR =
1 - RR
Difference between effect modification and confounding bias?
Effect modification is something to be studied; Present when effect of the main exposure is modified by presence of another variable.
Power
= 1 - Beta; Beta = Pr(type II error) = Pr of rejecting null hypothesis when it is truly false = Pr difference when there IS one = Maximize for clinical trials!