st: data management question

[Maria Cecilia Vieira da Silva <mcvieira@mapigroup.com>]

Hello,
My data set looks like below. Each patient (here patient 1 and 2) takes or not pills each day (from day 1 to day 12). I would like to estimate the median number of days that the patients take the pill uninterruptedly. For example, the median is 3 in the case below - Patient 1 (3, 4, 1) and Patient 2 (3, 2).
Any suggestions about how to implement it in a large data set?
I though about creating a dummy (number of pills>0) and performing sums for the series bordered by zeros, but I am not sure about a command that would allow me to create subseries defined as series of numbers bordered by zeros. Actually, if I could create such subseries, it would suffice to perform a count.
Thanks,
Maria Cecilia


id day number of pills
1 1 1
1 2 2
1 3 1
1 4 0
1 5 0
1 6 2
1 7 1
1 8 2
1 9 3
1 10 0
1 11 0
1 12 1
2 1 0
2 2 0
2 3 0
2 4 1
2 5 1
2 6 1
2 7 0
2 8 0
2 9 0
2 10 2
2 11 2
2 12 0
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