Stata 9, Epi tables, Survey, Factor
• Tables for epidemiologists
• Survey commands
• Factor analysis
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Tables for epidemiologists
• Commands
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cs
ir
cc
mcc
Cohort study with incidence proportion
Cohort study with incidence rate
Case-control
Matched case-control
• Example
– cc diseased exposed, by(sex) Stratified MH-OR
• Calculator (i=immideate)
– csi 100 50 900 950
– iri 100 50 1000 1000
– cci 10 90 5 95
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RR
RR
OR
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Survey commands
• Purpose
– A family of commands to account for survey
designg effects (stratification (and clustering))
• Workflow
– svyset [pweight=p1],strata(country)
probability weights and stratification
– svy:mean x1
weighted mean
set
– Regressions do not need weighting
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Factor analysis
• Purpose
– Find latent factors from a large set of variables
• Workflow
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factor x1 x2 x3
factor analysis
screeplot
plot eigenvalues
factor x1 x2 x3, factors(3) max 3 factors
estat kmo
sampling OK?
rotate
varimax rotation
loadingplot
2 first factors
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