Stacked bar chart showing changing proportions in a population over time.

[David Metcalfe]

Hello all. Sorry for the novice query but I have struggled with this for the best part of today. I am trying to visualise whether or not a score (on a scale 0-10) has changed over time amongst patients recruited to a study. I do not have multiple data points for each patient and so I am trying to see whether the population of patients recruited has changed over time.

In my data (below), "amts" is the score and "timesincelaunch" is the time period. As the median is "9" throughout the dataset, I can't really plot medians on a line graph and would like to create a stacked bar chart instead, i.e. showing the proportion of patients with each score (10, 9, 8) at each time point. I have tried

graph bar amts, over(timesincelaunch) stack"

and using "collapse" but neither approach led to anything meaningful.

Can anyone suggest a way forward?

* Example generated by -dataex-. To install: ssc install dataex
clear
input byte amts float timesincelaunch
10  0
 1  1
10  6
10  7
 9  9
10  9
 6  9
 4 10
 8 10
10 10
end

[Nick Cox]

I wouldn't use a stacked bar chart here at all. It's often a poor design and with (if I understand this correctly) 11 distinct values you need a legend and impose a burden of scanning back and forth on the reader. Consider instead

* Example generated by -dataex-. To install: ssc install dataex
clear
input byte amts float timesincelaunch
10  0
 1  1
10  6
10  7
 9  9
10  9
 6  9
 4 10
 8 10
10 10
end

tabplot amts timesincelaunch, yasis xasis horizontal 

histogram amts, by(timesincelaunch, row(1)) horizontal discrete freq bfcolor(ltblue) blcolor(blue) yla(, ang(h))

Here for tabplot see e.g.


SJ-16-2 gr0066 . . . . . . Speaking Stata: Multiple bar charts in table form
(help tabplot if installed) . . . . . . . . . . . . . . . . N. J. Cox
Q2/16 SJ 16(2):491--510
provides multiple bar charts in table form representing
contingency tables for one, two, or three categorical variables

or search for threads within the forum.

[David Metcalfe]

Thank you very much - these solutions work much better than the one I was working towards.