1. Proportions and Sample Size
Day 5
Proportions
and
Sample Size

2. Motivating Question What factors are associated with mortality?
ICU characteristics
patient characteristics
complications
comorbid diseases

3. Confidence Intervals ci death, bi ci death, bi by(phys)
ci death, bi by(npnight)
ci death, by(nonwhite) bi
ci death, by(reint) bi

4. Binomial Test
Fisher’s exact test
2 test
tab cc cs

5. Fisher’s exact test tab death ruptured, exact col
cs death ruptured, exact col

6. Fisher’s exact test tab death diabetes, exact col
gen diabetes=cond(mdmR==1 |sdmR==1,1,0)
tab death diabetes, exact col
cs death diabetes, exact

7. 2 test
tab death reintub, chi col
tab death reintub, chi exact col

8. Sample Size Comparing 2 means Comparing 2 proportions Options
sampsi m1 m2, sd1(s1) sd2(s2)
sampsi m1 m2, sd1(s)
Comparing 2 proportions
sampsi p1 p2
Options
power
alpha