1. Introduction to Graphing in SAS
Greg Grandits, Division of Biostatistics
March 6, 2017

2. Treatment of Mild Hypertension Study (TOMHS)
Clinical Trial of persons with “mild” hypertension
Four clinical centers in U.S.
902 participants
Six treatment groups (5 classes of BP meds)
Diuretic
Beta Blocker
Calcium Channel Blocker
Alpha Blocker
ACE inhibitor
Placebo
All participants intervened to reduce weight and intake of sodium 2

3. TOMHS SAS Dataset (1 Row per participant)
Demographics
Age
Gender
Ethnicity
Blood Pressure, Pulse and Weight
Treatment group (1-6)
Blood total and HDL cholesterol
Serum potassium and glucose
Data at baseline, 6-months, and 12-months

5. Graphing With SAS PROC SGPLOT PROC SGPANEL Histograms Box plots
Barcharts
Scatter plots (regression line)
Series plots
PROC SGPANEL
Paneled plots
Example: Boxplots of Change in BP by Group, Paneled by visit

7. proc format;
value sex 1 = 'Men' 2='Women';
value group 1='BB' 2='CCB' 3='Diuretic‘
4='AB' 5='ACE' 6='Placebo';
value visit 0='Baseline' 6='Month 6' 12='Month 12';
value active 1='Active' 2='Placebo';
value race 1 = 'White' 2='Black' 3='Asian' 4='Other';
run;

8. * Reading in the data and defining variables;
libname t '.';
data temp;
set t.tomhs;
bmi = (wtbl* )/(height*height);
sbpdif12 = sbp12 - sbpbl;
if group in(1,2,3,4,5) then active = 1; else active = 2;
run;

9. * Set up;
ods graphics / reset noborder;
ods listing ; * Writes each graph to a png file;

10. * Histogram using sgplot;
proc sgplot;
histogram bmi;
density bmi/type=normal;
density bmi/type=kernel;
yaxis label='Percent' grid ;
xaxis label='BMI (kg/m2)';
title 'Histogram of BMI at Baseline
in TOMHS';
run;

11. * Boxplots by Gender ;
proc sgplot;
vbox bmi/category=sex;
yaxis label='BMI (kg/m2)' grid;
xaxis display=(nolabel);
title 'Boxplot of BMI at Baseline by Gender in TOMHS';
format sex sex.;
run;

12. * Vertical bar chart;
proc sgplot;
vbar clinic/stat=freq datalabel;
xaxis label='Clinical Center';
yaxis label='No. of Participants';
title 'Number of Perticipants Enrolled by Clinical Center in TOMHS';
run;

13. proc sgplot;
vbar clinic/stat=percent datalabel;
xaxis label='Clinical Center';
yaxis label='% of Participants' ;
title 'Percent of Participants
Enrolled by Clinical Center in TOMHS';
run;

14. * Response chart;
proc sgplot noautolegend;
vbar group/response=sbpdif12 stat=mean limitstat=stderr ;
yaxis label = 'Mean SBP Change (mm Hg)';
xaxis label = 'Treatment Group';
title 'Mean Systolic BP Change at
12-Months by Group in TOMHS';
format group group.;
run;

15. proc sgplot;
vbar race/stat=freq datalabel group=sex groupdisplay=cluster name='sex';
xaxis label='Race/Ethnicity';
yaxis label='No. of Participants';
title 'Number of Participants Enrolled by Ethnicity and Gender in TOMHS';
keylegend 'sex' / title='' ;
format race race.;
format sex sex.;
run;

16. * Standard scatter plot with regression line;
proc sgplot;
reg y=sbpbl x=dbpbl;
yaxis label = 'SBP (kg/m2)';
xaxis label = 'Age (y)';
title 'Scatter Plot of SBP Versus DBP at Baseline in TOMHS';
run;

18. * Create long format file;
data long;
set temp;
keep active visit sbp dbp;
sbp = sbpbl;
dbp = dbpbl;
visit = 0;
if sbp ne . then output;
sbp = sbp6;
dbp = dbp6;
visit = 6;
sbp = sbp12;
dbp = dbp12;
visit = 12;
run;

19. Obs
ptid
active
sbp
dbp
visit 1
A00001
139.5
87.0 2
122.0
74.0 6 3
A00010
144.0
90.5 4
117.0 5
129.0
71.0 12
A00021
141.0 7
116.0
65.0 8
118.0
69.0 9
A00023
134.0
92.5 10
139.0
92.0

20. * Create boxplots by group and visit using proc sgpanel;
proc sgpanel data=long noautolegend;
panelby visit/columns=3 novarname ;
rowaxis label='BP (mmHg)' grid;
colaxis integer display=(nolabel);
vbox sbp/category=active;
format active active.;
format visit visit.;
title 'Boxplots of SBP by Visit
and Group in TOMHS';
run;

21. proc sgpanel data=long noautolegend;
panelby visit/columns=3 novarname ;
rowaxis label='BP (mmHg)' grid;
colaxis display=(nolabel);
vbox sbp/category=active group=active
nofill nomean ;
format active active.;
format visit visit.;
title 'Boxplots of SBP by Visit
and Group in TOMHS';
styleattrs datacolors=(blue red);
run;

23. output out=plot mean=msbp mdbp stderr=sesbp sedbp n=nsbp ndbp; run;
proc means nway;
class active visit;
var sbp dbp ;
output out=plot mean=msbp mdbp
stderr=sesbp sedbp
n=nsbp ndbp;
run;
Obs
active
visit
_TYPE_
_FREQ_
msbp
mdbp
sesbp
sedbp
nsbp
ndbp 1 3
668 2 6
639 12
627 4
234 5
225
221

24. proc sgplot data=plot ;
series x=visit y=msbp/markers group=active ;
xaxis label='Follow-up Visit' type=discrete ;
yaxis label='SBP (mmHg)' grid ;
title 'Average SBP Over Follow-up for
Active and Placebo Groups in TOMHS';
format active active.;
label active= 'Group';
run;

26. data plot;
set plot (drop=_freq_ _type_);
uppsbp = msbp + sesbp;
lowsbp = msbp - sesbp;
uppdbp = mdbp + sedbp;
lowdbp = mdbp - sedbp;
run;

27. proc sgplot data=plot ;
styleattrs datasymbols=(circlefilled diamondfilled);
series x=visit y=msbp/markers group=active name='group';
scatter x=visit y=msbp/group=active yerrorlower=lowsbp yerrorupper=uppsbp ;
xaxis label='Follow-up Visit' type=discrete offsetmin= offsetmax=0.05 ;
yaxis label='SBP (mmHg)' grid minor;
keylegend 'group' / title='' ;
title 'Average SBP Over Follow-up for Active and Placebo Groups in TOMHS';
format active active.;
label active= 'Group';
run;