** USING THE MIDPOINT SCORES ;
data table_2_7a;
input malf $ alc count @@;
datalines;
Absent 0.0 17066   Present 0.0 48
Absent 0.5 14464   Present 0.5 38
Absent 1.5   788   Present 1.5  5
Absent 4.0   126   Present 4.0  1
Absent 7.0    37   Present 7.0  1
;

proc freq order=data; weight count;
tables alc*malf/chisq;
test pcorr;

proc genmod order=data; class alc malf;
model count = alc malf / dist = poi link=log residuals; 
run;

************************************************************;
************************************************************;
************************************************************;

** USING THE MIDRANK SCORES ;
data table_2_7b;
input malf $ alc count @@;
datalines;
Absent 8557.5  17066   Present  8557.5 48
Absent 24365.5 14464   Present 24365.5 38
Absent 32013     788   Present 32013    5
Absent 32473     126   Present 32473    1
Absent 32555.5    37   Present 32555.5  1
;

proc freq order=data; weight count;
tables alc*malf/chisq;
test pcorr;

proc genmod order=data; class alc malf;
model count = alc malf / dist = poi link=log residuals; 
run;