Test 4 Flashcards
Purpose of Stats in Epidemiology
-Describe basic biostatistic used in epidemiology
-Describe concepts underlying statical tests
-to be able to improve basic biostatistical used in epidemiology studies
Categorical Variable
Variables that place individuals into a category
Ex: age, race, height, hair color
Ordinal Variable
“Ordinal” = “order” or “position”
Interval Variable
Equal steps or measures between points
Ex: $5 vs $10
Numerical Variable
Infinite numbers within the range of the variables any value is possible- including fractions
Discrete variable
limited numbers available- fractions not included
Ex: number of cars in VSU parking lot
Bell shaped curve
normal distribution of data
Mean
average
Median
Middle number
Mode
most frequently occurring number
Variance
How far the numbers spread out from the mean
(more spread out = high volume distribution)
Standard deviation
How much of the data set is spread out from the mean
Confidence Interval
estimate of the lowest and highest value that might be expected (realistic value)
Correlation
A measure of the extent to which two factors vary together, and thus of how well either factor predict the other
Causation
Indicates that 1 event is the result of the occurrence of the other event
p-value
unlikely to have occurred by chance (probability of occurrence by chance)
Statistical Significance
not random, not by chance p<0.05
Clinical meaningfulness
possible random, may/may not be statistical significance
Confidence intervals provide _____ for a population expectation
reasonable bounds
P-value provides statistical significance estimates ____ to have occurred by chance
Unlikely
Correlation tells us how much and in what _______ to variables are related two each other
direction
Plausibility =
reliability
Dose response
dose is a recommended amount, increase amount has a different payout at the end
Amount of dependent variable affects the ____
Independent variable
What percentage is the middle of standard deviation?
68%
P- value is another name for?
Statistical Significance
P-value is chance, if less than 5% ____
thats not chance, which means its not p-value
