FILENAME goptions URL "http://192.38.117.59/~linearpredictors/datafiles/goptions.sas";
%include goptions;

FILENAME url URL "http://192.38.117.59/~linearpredictors/datafiles/readFever.sas";
%include url;

DATA fever; SET fever;
    IF weight=0 THEN weight=.;
    ga=(gwbirth>31)+(gwbirth>32)+(gwbirth>33)+(gwbirth>34)+(gwbirth>35)+
    (gwbirth>36)+(gwbirth>37)+(gwbirth>38)+(gwbirth>39)+(gwbirth>40);
    parity2=(parity>0); IF parity=. THEN parity2=.;
PROC SORT; BY ga;
RUN;    

PROC UNIVARIATE DATA=fever pctldef=3 NOPRINT;
    BY ga;
    VAR weight;
    OUTPUT OUT=sgalimits
    PCTLPTS = 5
    PCTLPRE = pct;    
RUN;    

DATA sgalimits; SET sgalimits;
    IF ga=0 THEN DELETE;
RUN;

DATA fever; SET fever;
    IF ga=0 then ga=1;
RUN;

DATA fever; MERGE fever sgalimits; BY ga;
   sga=(weight<pct5);
   IF weight=. THEN sga=.;
RUN;

DATA casecon; SET fever;
  IF sga=1 THEN OUTPUT;
  IF sga=0 THEN DO;
    IF RANUNI(1)<0.15 THEN OUTPUT; END;
RUN;

/* NB new control sample (and 2 fewer sga cases) */

PROC FREQ DATA=casecon;
    TABLES parity2*smoke*sga/NOCOL NOPERCENT;
RUN;

PROC FREQ DATA=casecon;
    TABLES parity2*sga/NOCOL NOPERCENT;
RUN;

PROC FREQ DATA=casecon;
    TABLES smoke*sga/NOCOL NOPERCENT;
RUN;


/*
PROC GENMOD DATA=fever DESCENDING;
    CLASS smoke;
    MODEL sga=parity2 smoke/DIST=BIN TYPE3;
    ESTIMATE '1 vs. 0' smoke -1 1 0;
    ESTIMATE '2 vs. 0' smoke -1 0 1;    
RUN;    

PROC GENMOD DATA=fever DESCENDING;
    CLASS smoke;
    MODEL sga=parity2 smoke parity2*smoke/DIST=BIN TYPE3;
RUN;    

PROC GENMOD DATA=fever DESCENDING;
    CLASS smoke;
    MODEL sga=parity2 smoke/DIST=BIN TYPE3 LINK=PROBIT;
    ESTIMATE '1 vs. 0' smoke -1 1 0;
    ESTIMATE '2 vs. 0' smoke -1 0 1;    
RUN;    

PROC GENMOD DATA=fever DESCENDING;
    CLASS smoke;
    MODEL sga=parity2 smoke parity2*smoke/DIST=BIN TYPE3 LINK=PROBIT;
RUN;    

PROC GENMOD DATA=fever DESCENDING;
    CLASS smoke;
    MODEL sga=parity2 smoke/DIST=BIN TYPE3 LINK=LOG;
    ESTIMATE '1 vs. 0' smoke -1 1 0;
    ESTIMATE '2 vs. 0' smoke -1 0 1;    
RUN;    

PROC GENMOD DATA=fever DESCENDING;
    CLASS smoke;
    MODEL sga=parity2 smoke parity2*smoke/DIST=BIN TYPE3 LINK=LOG;
RUN;    

PROC GENMOD DATA=fever DESCENDING;
    CLASS smoke;
    MODEL sga=parity2 smoke/DIST=BIN TYPE3  LINK=IDENTITY;
    ESTIMATE '1 vs. 0' smoke -1 1 0;
    ESTIMATE '2 vs. 0' smoke -1 0 1;    
RUN;    

PROC GENMOD DATA=fever DESCENDING;
    CLASS smoke;
    MODEL sga=parity2 smoke parity2*smoke/DIST=BIN TYPE3 LINK=IDENTITY;
RUN;    
*/