Hello! I am running the following macro for my propensity score matching which I have copy pasted from this code published online - http://www2.sas.com/proceedings/sugi29/165-29.pdf
What this code essentially does is generates propensity scores in the first part of the logistic regression and the macro then assigns cases to controls. Based on the number of controls one chooses to assign to each case, it will assing one control, two controls or three controls.
This is the code -
ods graphics on;
proc logistic data = aim1.propensity_group1_step10 plots(maxpoints = none) outest=betas;
model oo (event = '1') = age gender CCI_score sum_ED sum_Inpatient sum_Outpatient sum_Others phar_count / lackfit outroc=roc1;
;
output out= aim1.propen prob=prob ;
title 'logistic regression for Group 1';
RUN;
ods graphics off;
/* Call Macro and Perform 1:1 Match */
%OneToManyMTCH(aim1,propen,overdose,encrypted_mbr,Matches_1,1);
/* Call Macro and Perform 1:2 Match */
%OneToManyMTCH(aim1,propen,overdose,encrypted_mbr,Matches_2,2);
/* Call Macro and Perform 1:3 Match */
%OneToManyMTCH(aim1,propen,overdose,encrypted_mbr,Matches_3,3);
/* ***************************************** */
/* ***************************************** */
/* Matching Macro */
/* ***************************************** */
/* ***************************************** */
%MACRO OneToManyMTCH (
Lib, /* Library Name */
Dataset, /* Data set of all patients */
depend, /* Dependent variable that indicates Case or Control */
/* Code 1 for Cases, 0 for Controls */
PatientN, /* Patient ID */
matches, /* Output data set of matched pairs */
NoContrls); /* Number of controls to match to each case */
/* ********************* */
/* Macro to Create the Case and Control Data sets */
/* ********************* */
%MACRO INITCC(CaseAndCtrls,digits);
data tcases (drop=cprob)
tctrl (drop=aprob) ;
set &CaseAndCtrls. ;
/* Create the data set of Controls */
if &depend. = 0 and prob ne . then
do;
cprob = Round(prob,&digits.);
Cmatch = 0;
Length RandNum 8;
RandNum=ranuni(1234567);
Label RandNum='Uniform Randomization Score';
output tctrl;
end;
/* Create the data set of Cases */
else if &depend. = 1 and prob ne . then
do;
Cmatch = 0;
aprob =Round(prob,&digits.);
output tcases;
end;
run;
%SORTCC;
%MEND INITCC;
/* ********************* */
/* Macro to sort the Cases and Controls data set */
/* ********************* */
%MACRO SORTCC;
proc sort data=tcases out=&LIB..Scase;
by prob;
run;
proc sort data=tctrl out=&LIB..Scontrol;
by prob randnum;
run;
%MEND SORTCC;
/* ********************* */
/* Macro to Perform the Match */
/* ********************* */
%MACRO MATCH (MATCHED,DIGITS);
data &lib..&matched. (drop=Cmatch randnum aprob cprob start oldi curctrl matched);
/* select the cases data set */
set &lib..SCase ;
curob + 1;
matchto = curob;
if curob = 1 then do;
start = 1;
oldi = 1;
end;
/* select the controls data set */
DO i = start to n;
set &lib..Scontrol point = i nobs = n;
if i gt n then goto startovr;
if _Error_ = 1 then abort;
curctrl = i;
/* output control if match found */
if aprob = cprob then
do;
Cmatch = 1;
output &lib..&matched.;
matched = curctrl;
goto found;
end;
/* exit do loop if out of potential matches */
else if cprob gt aprob then
goto nextcase;
startovr: if i gt n then
goto nextcase;
END; /* end of DO LOOP */
/* If no match was found, put pointer back*/
nextcase:
if Cmatch=0 then start = oldi;
/* If a match was found, output case and increment pointer */
found:
if Cmatch = 1 then do;
oldi = matched + 1;
start = matched + 1;
set &lib..SCase point = curob;
output &lib..&matched.;
end;
retain oldi start;
if _Error_=1 then _Error_=0;
run;
/* get files of unmatched cases and controls */
proc sort data=&lib..scase out=sumcase;
by encrypted_mbr;
run;
proc sort data=&lib..scontrol out=sumcontrol;
by encrypted_mbr;
run;
proc sort data=&lib..&matched. out=smatched (keep=encrypted_mbr matchto);
by encrypted_mbr;
run;
data tcases (drop=matchto);
merge sumcase(in=a) smatched;
by encrypted_mbr;
if a and matchto = . ;
cmatch = 0;
aprob =Round(prob,&digits.);
run;
data tctrl (drop=matchto);
merge sumcontrol(in=a) smatched;
by encrypted_mbr;
if a and matchto = . ;
cmatch = 0;
cprob = Round(prob,&digits.);
run;
%SORTCC
%MEND MATCH;
/* ********************* */
/* Macro to call Macro MATCH for each of the 8-digit to 1-digit matchs */
/* ********************* */
%MACRO CallMATCH;
/* Do a 8-digit match */
/*%MATCH(Match8,.0000001);*/
/* Do a 7-digit match on remaining unmatched*/
/*%MATCH(Match7,.000001);*/
/* Do a 6-digit match on remaining unmatched*/
/*%MATCH(Match6,.00001);*/
/* Do a 5-digit match on remaining unmatched*/
%MATCH(Match5,.0001);
/* Do a 4-digit match on remaining unmatched */
%MATCH(Match4,.001);
/* Do a 3-digit match on remaining unmatched */
%MATCH(Match3,.01);
/* Do a 2-digit match on remaining unmatched */
%MATCH(Match2,.1);
/* Do a 1-digit match on remaining unmatched */
%MATCH(Match1,.1);
%MEND CallMATCH;
/* ********************* */
/* Macro to Merge all the matches files into one file */
/* ********************* */
%MACRO MergeFiles(MatchNo);
data &matches.&MatchNo. (drop = matchto);
set &lib..match5(in=a) &lib..match4(in=b) &lib..match3(in=c)
&lib..match2(in=d) &lib..match1(in=e);
if b then matchto=matchto + 100000;
if c then matchto=matchto + 10000000;
if d then matchto=matchto + 1000000000;
if e then matchto=matchto + 100000000000;
run;
/*set &lib..match8(in=a) &lib..match7(in=b) &lib..match6(in=c) &lib..match5(in=d)
&lib..match4(in=e)
&lib..match3(in=f) &lib..match2(in=g) &lib..match1(in=h);
if a then match_&MatchNo. = matchto;
if b then match_&MatchNo. = matchto + 10000;
if c then match_&MatchNo. = matchto + 100000;
if d then match_&MatchNo. = matchto + 1000000;
if e then match_&MatchNo. = matchto + 10000000;
if f then match_&MatchNo. = matchto + 100000000;
if g then match_&MatchNo. = matchto + 1000000000;
if h then match_&MatchNo. = matchto + 10000000000;
run;*/
%MEND MergeFiles;
/* ******************************* */
/* ******************************* */
/* Perform the initial 1:1 Match */
/* ******************************* */
/* ******************************* */
/* Create file of cases and controls */
%INITCC(&LIB..&dataset.,.00000001);
/* Perform the 8-digit to 1-digit matches */
%CallMATCH;
/* Merge all the matches files into one file */
%MergeFiles(1)
/* ********************************* */
/* ********************************* */
/* Perform the remaining 1:N Matches */
/* ********************************* */
/* ********************************* */
%IF &NoContrls. gt 1 %Then %DO;
%DO i = 2 %TO &NoContrls.;
%let Lasti=%eval(&i. - 1);
/* ********** */
/* Start with Cases from the last Matched Cases file and the remaining Un-Matched */
/* Controls. NOTE: The Unmatched Controls file (Scontrol) is created at end of the */
/* previous match */
/* Select the Matched Cases from the last Matched File */
data &LIB..Scase;
set &matches.&Lasti.;
where &Depend. = 1;
run;
/* ********** */
/* Perform the 8-1 digit matches between Matched Cases and the Unmatched Controls */
%CallMATCH;
/* ********** */
/* Merge the 8-digit to 1-digit matches files into one file */
%MergeFiles (&i.)
%DO m=1 %TO &Lasti.;
data &matches.&i;
set &matches.&i.;
if &Depend.=0 then Match_&m. = .;
run;
%END;
/* ********** */
/* Determine which OLD Controls correspond to the kept Cases */
%DO c = 1 %TO &Lasti.;
/* Select the KEPT Cases */
proc sort data=&matches.&i. out=skeepcases (keep = Match_&c.);
by Match_&c.;
where &Depend. = 1;
run;
/* Get the OLD Controls */
proc sort data = &matches.&Lasti. out = soldcontrols&c.;
by Match_&c.;
where &Depend. = 0 and Match_&c. ne . ;
run;
/* Get the OLD Controls that correspond to the kept Cases */
data keepcontrols&c.;
merge skeepcases (in = a) soldcontrols&c. (in = b);
by Match_&c.;
if a;
run;
%END;
/* ********** */
/* Combine all the OLD Controls into one file */
data keepcontrols;
set keepcontrols1 (obs=0);
run;
%DO k = 1 %TO &Lasti.;
data keepcontrols;
set keepcontrols keepcontrols&k.;
run;
%END;
/* ********** */
/* Append the OLD matched Controls to the new file of matched cases and controls */
data &matches.&i.;
set &matches.&i. keepcontrols;
run;
/* ********** */
/* If there are more matches to be made, add the previously matched, but not kept, */
/* controls back into the pool of unmatched controls */
%if &i. lt &NoContrls. %then %do;
%DO z = 1 %TO &Lasti.;
/* Select all the KEPT Cases */
proc sort data=&matches.&i. out=skeepcases (keep = Match_&z.);
by Match_&z.;
where &Depend. = 1;
run;
/* Select all the OLD Controls */
proc sort data = &matches.&Lasti. out = soldcontrols&z.;
by Match_&z.;
where &Depend. = 0 and Match_&z. ne .;
run;
/* Keep the OLD Controls that correspond to the NOT KEPT Cases */
/* Drop the previuos Match_X variable */
data AddBackControls&z. (drop = Match_&z.);
merge skeepcases (in = a) soldcontrols&z. (in = b);
by Match_&z.;
if b and not a;
run;
%END; /* End DO */
/* Drop the previuos Match_X variable */
data &LIB..Scontrol (drop = Match_&lasti. );
set &LIB..Scontrol;
run;
/* Append */
%DO y = 1 %TO &Lasti.;
data &LIB..Scontrol;
set &LIB..Scontrol AddBackControls&y.;
run;
%END; /* End DO */
%end; /* End IF */
%END; /* End Main DO */
%END; /* End Main IF */
/* ************************************* */
/* ************************************* */
/* Save the final matched pairs data set */
/* ************************************* */
/* ************************************* */
/* Sort file by Treatment Variable */
proc sort data=&matches.&NoContrls. out = &lib..&matches.;
by &depend.;
run;
%MEND OneToManyMTCH;
The problem is - in the section that I have bolded, the work Match in "Match_&m." appears as red and therefore, the macro does not run as it is supposed to. I also tried re-typing that section but I am not sure what is going wrong.
I would greatly appreciate any help with this!
Thank you.
