# Multivariate Statistical Analysis and Modeling Flashcards

what are statistics used for?

to discern justifiable differences in quantitative patterns

give 3 classic statistical tests and why they are not practical for epidemiology

- basic t tests
- ANOVA
- Chi squared

too burdensome to apply to situations where multiple variables and their interactions are in question

describe the T test and give an example of how it could be used

tests whether significant differences, not attributable to random chance, are present in continuous data; could use for averaging hemoglobin levels in two different groups of people

what does the chi squared test do? give an example

tests significance between groups of non-continuous data

examples are infected versus not infected, vaccinated or not vaccinated

what are chi squared tests useful for?

2x2 contigency tables

what is Fisher’s exact test?

tests for significance in much the same way as the chi squared test does, but works with ANY SIZE DATA SET!!

what does the Fisher’s exact test give?

gives an exact P value rather than an approximation like other tests do

what can Fisher’s exact test also be applied to?

2x contigency tables

what is mutlivariable regression? (2)

- multiple independent variables are regressed on a single dependent variable
- all variables are considered together to discern correlations either individually or in combinations

what does multivariate analysis allow for?

allows more than two variables to be analyzed at once

is multivariable regression a type of multivariable analysis?

not usually considered under the heading, but is technically multivariate analysis

what are the 2 general types of multivariate analysis technique?

- asnalysis of dependence
- analysis of independence

describe the analysis of dependence multivariate analysis technique

where one or more variables are dependent variables, to be explained to predicted by others

give 3 analysis of dependence multivariate analysis tests

- multivariable regression
- PLS (partial least squares)
- MDA (multiple discriminant analysis)

where is multivariable regression analysis often seen?

in cohort studies