Flashcards in Behavioral Science/Stats Deck (57)
Study type that establishes prevalence
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
TP / (TP + FN) = Pr (T+|D+)
TN / (TN + FP) = Pr (T-|D-)
Pr (D+|T+) = TP / (TP + FP)
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)]
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.
= 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!
Type 1 v. type 2 error
1st and foremost, making something out to be when there isn't anything. (Rejecting H0 when it is true). 2nd, saying nothing when there is (Fail to reject, when H0 is false)
Selection bias - selecting hospitalized patients as the control
The tendency for a study population to affect an outcome due to the knowledge of being study. e.g. behavioral studies
Researcher's beliefs in efficacy of treatment potentially affecting the outcome
Number needed to harm?
Precision vs. accuracy?
Accuracy has to do with close to REAL number. Precision has to do with ability to REPRODUCE a result
Lead-time bias vs. recall bias?
Lead-time bias occurs when the early detection of a condition is interpreted as increased survival. Recall bias is when awareness of the condition leads to increased recall (e.g. retrospective studies)