/* Program from 
   Rick Wicklin, "Create a waterfall plot in SAS", The DO Loop, April 20, 2015.
   http://blogs.sas.com/content/iml/2015/04/20/waterfall-plot.html
*/
proc format;
value RECISTFmt   1='Disease progression'  2='Stable disease'
                  3='Partial response'     4='Complete response';
run;

data Tumor;
format PatientID z4. Response percentN7. RECIST RECISTFmt.;
input  PatientID Response RECIST;
datalines;
1001 -0.75 2 
1002 -0.73 3 
1003 -0.51 2 
1004 -0.09 2 
1005 -0.10 2 
1006 -0.17 2 
1007 -1.00 3 
1008 -0.83 3 
1009 -0.65 2 
1010 -0.53 2 
1011 -1.00 4 
1012 -0.48 3 
1013 -0.47 3 
1014 -0.85 3 
1015 -0.58 3 
1016  0.54 1 
1017 -1.00 3 
1018 -0.68 3 
1019 -0.25 1 
1020  0.21 1 
1021 -0.87 3 
1022 -0.21 2 
1023 -0.29 2 
1024 -0.20 1 
1025 -0.43 3 
1026 -0.50 3 
1027 -0.74 3 
1028 -1.00 3 
1029 -0.36 3 
1030 -0.44 3 
1031  0.22 2 
1032 -0.59 3 
1033 -0.26 2 
1034 -0.89 3 
1035 -0.57 3 
1036 -0.72 2 
1037 -0.76 3 
1038 -0.66 3 
1039 -0.44 3 
1040 -0.31 3 
1041 -0.40 3 
1042 -0.57 3 
1043 -0.74 3 
1044 -0.13 2 
1045 -0.07 1 
1046 -0.05 2 
1047 -0.29 2 
1048 -0.51 3 
1049 -0.70 3 
1050 -0.35 3 
1051 -0.43 3 
1052 -0.34 2 
1053 -0.87 3 
1054 -0.34 3 
1055 -0.59 3 
1056 -0.45 3 
1057 -0.26 2 
1058 -0.22 2 
1059 -1.00 3 
1060 -0.75 3 
1061 -0.83 2 
1062 -0.38 3 
1063 -0.70 3 
1064 -0.12 2 
1065 -0.32 3 
1066 -0.15 2 
1067 -0.49 3 
1068 -0.50 3 
1069  0.00 1 
1070 -0.41 3 
1071 -0.41 3 
1072 -0.50 3 
1073 -0.76 2 
1074 -0.78 3 
1075 -0.18 2 
1076  0.00 1 
1077  0.44 1 
1078 -0.23 2 
1079 -0.34 3
;

/* Sort by response and enumerate */
proc sort data=Tumor out=Waterfall;
   by descending Response RECIST;  *use RECIST code to break ties;
run;

data Waterfall;
   set Waterfall;
   Position + 1;                   /* Position = _N_ */
run;

title "Percent Change in Tumor Burden (N=79)";
footnote justify=left "After Gillespie (2012)";
footnote2 justify=left "Data from Kwak et al. (2010)";

/* Create a waterfall plot by using the VBAR (or HBAR) statement */
ods graphics / width=600px height=400px;
proc sgplot data=Waterfall;
   refline -0.3 / axis=y lineattrs=(pattern=shortdash);
   vbar Position / response=Response group=RECIST;
   xaxis label="Patient Number" fitpolicy=thin;
   yaxis label="Change from baseline (%)" values=(-1 to 1 by 0.2) valueshint;
   keylegend / location=inside down=2;
run;

/* Alternative: use the NEEDLE statement */
ods graphics / width=579px height=400px;
proc sgplot data=Waterfall;
   refline -0.3 / axis=y lineattrs=(pattern=shortdash);
   needle x=Position y=Response / baseline=0 group=RECIST
          lineattrs=(thickness=5px);
   xaxis label="Patient Number" values=(1, 5 to 75 by 5, 79) integer;
   yaxis label="Change from baseline (%)" values=(-1 to 1 by 0.2) valueshint;
   keylegend / location=inside down=2;
run;