Behavior/Biostats Flashcards
(52 cards)
Collects data from a group of people to assess frequency of disease (and related risk factors) at a particular point in time
Cross sectional study (observational)
“what is happening?”
Compares a group of people with disease to a group without a disease looking for prior exposure or risk factor
Case-control study (observational/retrospective)
eg: patient with COPD had higher odds of a history of smoking than patient without COPD
Odds Ratio
Case-control measure. (A/C)/(B/D)
Compares a group with a given exposure or risk factor to a group without such exposure. Looks to see if exposure increases likelihood of disease
Cohort study (observational and prospective or retrospective) eg: patient who smoked has higher risk of COPD than pt who didnt smoke
Relative risk
cohort study measure. Risk of developing disease in exposed group. (A/(A+B))/(C/(C+D))
Measures heritability/environmental influence
Twin concordance/Adoption studies
Drug trial
Phase I: safety (healthy pt)
Phase II: efficacy (diseased pt)
Phase III: compare to current meds on market (RCT)
Phase IV: long term SE
Probability a test detects disease when it’s present
Sensitivity = TP/(TP+FN)
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Probability that a test indicates non-disease when disease is absent
Specificity = TN/(TN+FP)
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Probability person has the disease given a positive test
Positive predictive value = TP/(TP+FP)
Probability that person is disease free given a negative test result
Negative predictive value = TN/(TN+FN)
number of new cases/population at risk in a time period
incidence
number of existing cases/population at risk in a time period
prevalance
1-RR
relative risk reduction
Difference in risk between exposed/unexposed groups
attributable risk
number of patients who need to be treated for 1 patient to benefit
number needed to treat 1/ARR
number needed to harm
number of patients who need to be exposed to a risk factor for 1 patient to be harmed 1/AR
unexposed risk - exposed risk
absolute risk reduction (ARR)
increased precision
decreased standard deviation
systematic error
decreased accuracy
early detection is confused with increased survival
lead time bias
self fulfilling prophecy, observer expectancy bias
pygmalion effect
groups who know they’re being studied behave differently
hawthorne effect
graph suggesting two different populations
bimodal distribution
