Summing over the column

Statsconsultancy — Tue, 27 Sep 2011 12:46:46 GMT

I have a data set like as follows

PatientID year adherence

1 1 0

1 2 1

1 3 1

2 1 1

2 2 1

3 1 1

3 2 1

3 3 0

3 4 1

What i want is to create a new variable that will give cumulative adherence at year "i". Thus the data with a new variable will look like

PatientID year adherence cumulativeAdherence

1 1 0 0

1 2 1 1

1 3 1 2

2 1 1 1

2 2 1 2

3 1 1 1

3 2 1 2

3 3 0 2

3 4 1 3

art297 — Tue, 27 Sep 2011 12:54:51 GMT

Couldn't you just use something like:

data want;

set have;

by PatientID;

if first.PatientID then cumulativeAdherence=adherence;

else cumulativeAdherence+adherence;

run;

topic Summing over the column in Statistical Procedures