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Behavioral Science
Epidemiology/Statistics
69
Medical
Graduate
01/17/2014

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Cards

Term
compares a group of people with disease to a group without
Definition
case-control
Term
study type that uses OR
Definition
case-control
Term
compares a group with a given expo rue or risk factor to a group without
Definition
cohort
Term
type of study that measures relative risk
Definition
cohort
Term
assesses frequency of a disease at a particular point in time
Definition
cross sectional study
Term
type of study that measures disease prevalence
Definition
cross-sectional
Term
compares monozygotic or dizygotic development of disease
Definition
twin concordance study
Term
compares siblings raised by biologic vs adoptive parents
Definition
adoption study
Term
phase I clinical trial
Definition
safety, toxicity, and pharmacokinetics
Term
phase II clinical tril
Definition
efficacy, optimal dosing, adverse effects
Term
phase III clinical trial
Definition
new treatment to the current standard of care
Term
phase IV of clinical trial
Definition
rare or longer-term adverse effects; post marketing surveillance
Term
sensitivity equation
Definition
TP/ (TP + FN)
Term
used for screening in diseases
Definition
sensitivity
Term
high value of _____ rules out disease
Definition
sensitivity
Term
specificity equation
Definition
TN / (TN + FP)
Term
used in confirmatory tests
Definition
specificity
Term
high value or ____ rules in disease
Definition
specificity
Term
PPV equation
Definition
TP / (TP + FN)
Term
meaning of PPV
Definition
probability that person actually has the disease given a positive test result
Term
NPV equation
Definition
TN / (FN + TN)
Term
meaning of NPV
Definition
probability that persn is disease free given a negative result
Term
what effect does decreasing the cutoff have on sensitivity?
Definition
increase sensitivity because will increase the number of positives
Term
what effect does increasing the cutoff have on specificity?
Definition
specificity will increase because there will be more true negatives
Term
point prevalence
Definition
total cases in a population at a given time / total population
Term
incidence equation
Definition
over a given time period / total population at risk during that time period
Term
how does prevalence relate to incidence and disease duration?
Definition
prevalence = incidence x disease duration
Term
how does prevalence relate to incidence with chronic diseases?
Definition
prevalence > incidence
Term
how does prevalence relate to incidence for acute disease states?
Definition
prevalence = incidence
Term
odd ratio equation
Definition
AD / BC
Term
how does odd ratio relate to relative risk?
Definition
OR approximates RR if prevalence of disease is low
Term
how do you calculate relative risk?
Definition
[a/(a+b)]/[c/(c+d)]
Term
what is attributable risk?
Definition
proportion of disease occurecnes that are attributable to the exposure
Term
how do you calculate attributable risk?
Definition
[a/(a+b)] - [c/(c+d)]
Term
what is absolute risk reduction?
Definition
reduction in risk associated with a treatment as compared to a placebo
Term
how do you calculate ARR?
Definition
[c/(c+d)] - [a/(a+b)]
Term
how do you calculate NNT?
Definition
1/ARR
Term
how do you calculate NNH?
Definition
1/AR
Term
precision
Definition
consistency and reproducibility of a test, absence of random variation
Term
accuracy
Definition
trueness of test measurements (validity)
Term
selection bias
Definition
nonrandom assignment to study groups
Term
recall bias
Definition
knowledge of presence of disorder alters recall by subjects
Term
sampling bias
Definition
subjects are not representative relative to general population; so results are not genearlizable
Term
lake look bias
Definition
info gathered at an inappropriate time
Term
procedure bias
Definition
subjects in different groups are not treated the same
Term
confounding bias
Definition
occurs with 2 closely associated factors; effects of 1 factor distorts he effect of the other
Term
lead-timebias
Definition
early detection confused withincreased survival; seen with improved screening
Term
Pygmalion effect
Definition
when a rsearcher's belief in the efficacy of a treatment changes the outcome of that treatment
Term
hawthorne effet
Definition
group being studied changes its behavior owing to the knowledge of being studied
Term
how do you calculate SEM?
Definition
SD / sqrt(n)
Term
positive skew
Definition
tail on right; mean > median > mode
Term
negative skew
Definition
tail on left; mean < median < mode
Term
null hypothesis
Definition
hypothesis of no difference
Term
alternative hypothesis
Definition
that ther is some difference
Term
type I error
Definition
stating there is an effet or difference when none exists
Term
type II error
Definition
stating there is not an effect when one exists
Term
power
Definition
probability of rejecting the null hypothesis when it is in fact false
Term
what things effect power?
Definition
increasing sample size -> increased power
- difference in compliance between tx groups
- total number of end points experienced by population
Term
what is meta-analysis?
Definition
pools data and integrates results from several similar studies to reach an overall conclusion
Term
how do you calculate CI?
Definition
x +/- z(SEM)
Term
z value for:
- 90%
- 95%
- 99%
Definition
- 1.645
- 1.96
- 2.58
Term
what value do you want the CI do you not want to include for:
- mean difference
- OR/RR
Definition
- 0
- 1
Term
t test
Definition
checks difference between the means of 2 groups
Term
ANOVA
Definition
checks difference between the means of 3 or more groups
Term
chi square
Definition
checks difference between 2 or more percentages or proportions
Term
correlation coefficienct
Definition
between -1 and 1; closer to 1 then the stronger the correlation
Term
primary prevention
Definition
prevent disease occurence
Term
secondary prevention
Definition
early detection of disease
Term
tertiary prevention
Definition
reduce disability from disease
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