Behavioral Science Flashcards
Study measuring disease prevalence and risk factor association in a snapshot of time.
Controls are patients without the risk factor.
CROSS-SECTIONAL STUDY
Prevalence odds ratio.
Study comparing prior exposure or risk factors for an outcome of interest.
Controls are patients who do not have the outcome regardless of prior exposure status.
CASE-CONTROL STUDY
Exposure odds ratio.
Susceptible to recall bias (always retrospective)
Control founding with matching
Study determining if exposure affects the likelihood of disease - can be prospective or historical.
Controls are patients without the risk factor.
COHORT STUDY
Relative risk.
Assessment of safety, toxicity, kinetics, and dynamics of a new drug.
PHASE I
Healthy volunteers.
Assessment of efficacy, dosing, and adverse effects of a new drug.
PHASE II
Patients with disease of interest.
Assessment of new drug vs standard of care.
PHASE III
Large randomized controlled trial.
Assessment of rare or long-term adverse effects.
PHASE IV
Postmarketing surveillance.
Proportion of people with disease who test positive.
SENSITIVITY
High sensitivity useful for ruling out disease (screening) - low false-negative rate.
Proportion of all people without disease who test negative.
SPECIFICITY
High specificity useful for ruling in disease (confirmatory) - low false-positive rate.
Proportion of positive test results that are true positives.
POSITIVE PREDICTIVE VALUE
Increases with increasing pretest probability (prevalence) - high pretest probability means higher PPV
Proportion of negative test results that are true negatives.
NEGATIVE PREDICTIVE VALUE
Decreases with increasing pretest probability (prevalence) - high pretest probability means lower NPV
Odds of exposure of people with the disease, compared with odds of exposure of people without the disease.
ODDS RATIO
If rows are exposed/unexposed and columns are disease/no disease then OR = ad/bc
Relative risk
RELATIVE RISK
Treatment Rate/Control Rate
If prevalence is low, OR = RR (rare disease assumption)
Absolute risk increase (Attributable Risk)
Treatment Rate - Control Rate
Relative Risk Reduction (RRR) - The proportion of risk reduction attributable to the intervention
RELATIVE RISK REDUCTION
RRR = 1 - RR = ARR/Control Rate
Note: ARP = (RR - 1)/RR
Absolute risk reduction (ARR)
Control Rate - Treatment Rate
Number needed to treat.
1/ARR
Number needed to harm.
1/ARI