Forest Plot for Overall Survival Confidence Interval

SAS Day 40: Forest Plot 

Tired looking across many overall response tables while comparing the same rate?  The forest plot is a perfect solution to summarise data from multiple resources and convert it into a single reader-friendly graph.  

 

Ideal Forest Plot:

When taking all the relevant studies, ask the same question with the same statistical model, identifies a common endpoint in papers and displays them on a single set of axis. The forest plot directly comparing the studies by showing the quantity and quality of the results all in one place. 

(🔷 means the most important study, and ⚫ size is according to the study population size)

Free-Photos / Pixabay

Done is better than perfect, so we will do a practical forest plot example.

Practical Forest Plot:

Instead of gathering all the relevant studies, we will compare the Overall Survival Rate different categories (Age group, Sex, Hispanic).

 

Interpretation:

The Forest plot did not show one category has significant Overall response rate than another, but Non-Hispanic group did show a little edge in the treatment. The blue dot is the Calculated 95% Confidence Interval based on the data. The red interval is the range of values within which you can be 95% certain the true value lies.

SAS Sample Dataset 

proc sort data=crr out=crr1;
by descending ord;
run;
*graph;
options orientation=landscape;
ods graphics on/ height=400px width=600px;

ods pdf nogfootnote nogtitle ;
title1 j=center "Graph 1";
title2 j=center " Forest Plot  for Overall Response Rate";
title3 j=center "x Population";
proc sgplot data=orr1;
scatter x=oc1 y=lbl /xerrorlower=clow
                     xerrorupper=chigh
                     markerattrs=or
          (symbol=CirleFilled size=4);
          refline 40 /axis=x;
          xaxis values=(0 to 100 by 20) display=(nolabel);
          yaxis valueattrs=(size=8pt) display=(nolabel);
yaxistable c3/ label="ORR(95% CI)" location=inside ;
run;
goptions reset=all; 
ods pdf close;
ods listing;

 

Happy Practicing and i decide to use a recycle bag to shopping today, so save some trees to make a forest plot!  

Reference:

https://www.students4bestevidence.net/tutorial-read-forest-plot/

 

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