/********************** birdlung.sas **************************/
title 'Logistic Regression on Bird Lung Data';

proc format;
     value ynfmt 0 = "No"  1 = "Yes";
     value sexfmt 0 = "Male"  1 = "Female";
     value sesfmt 0 = "Low"  1 = "High";

data tweet;
     infile '/folders/myfolders/2453f15/birdlung.data.txt';
     input cancer sex ses birdkeep age yrsmoke cigday;
     format sex sexfmt.;
     format ses sesfmt.;
     format cancer birdkeep ynfmt.;
     
proc freq;
     tables cancer sex ses birdkeep cigday;
     
proc means;
     var age yrsmoke cigday;  

proc logistic order=internal descending; /* Always use descending for 0-1 DV */
     model cancer = sex ses birdkeep age yrsmoke cigday;
     smoke: test yrsmoke = cigday = 0;