Stata 9, Epi tables, Survey, Factor

• Tables for epidemiologists

• Survey commands

• Factor analysis

20.04.23 H.S. 1

Tables for epidemiologists

• Commands– cs Cohort study with incidence proportion

– ir Cohort study with incidence rate

– cc Case-control

– mcc Matched case-control

• Example– cc diseased exposed, by(sex) Stratified MH-OR

• Calculator (i=immideate)– csi 100 50 900 950 RR

– iri 100 50 1000 1000 RR

– cci 10 90 5 95 OR

20.04.23 H.S. 2

Survey commands

• Purpose– A family of commands to account for survey

designg effects (stratification (and clustering))

• Workflow– svyset [pweight=p1],strata(country) set

probability weights and stratification

– svy:mean x1 weighted mean

– Regressions do not need weighting

20.04.23 H.S. 3

Factor analysis

• Purpose– Find latent factors from a large set of variables

• Workflow– 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

20.04.23 H.S. 4