1. Epidemiologic Tables and Transforming Variables
Day 4
Epidemiologic Tables
and Transforming Variables

2. Incidence Rates
Is there an association between breast cancer and exposure to multiple X-ray fluoroscopies (Howe, 1982)?

3. Incidence Rates
iri

4. Cohort Studies
Is there an association between mortality and low birthweight among infants (defined by birthweight < 2500g) in New York City in 1974?

5. Cohort Studies
csi

6. Case Control Studies
Is there an association between average daily alcohol consumption and esophageal cancer? (Tuyns, 1977).

7. Case Control Studies
cci

8. Using cc or cs on “real data”
What is the risk of death for individuals who have septicemia as a complication of abdominal aortic surgery compared to those who do not?
cc death septicem
cs death septicem

9. Matched Case Control Studies
Are individuals who drink 6 or more cups of coffee per day at increased risk of myocardial infarction?

10. Matched Case Control Studies
mcci

11. Transforming Variables
What “transformation” should we use to normalize
los?
totchg?
icuday?
age?

12. Transforming Variables
gladder
sktest
[ladder]

13. Conditional Statementsif
comes before the comma
e.g.
if age<50
if age>=50
if age==50
ci los if age<50
ci los if age<50, by(sex)

14. Conditional Statements
and (&), or (|)
ci los if age>50 & age<70
ci los if age<50 & sex==1
ci los if septic==1 | reintub==1