Hi,
I have some healthcare utilization data in the long format and would like to create simple data descriptives. The data looks like somewhat like this:

nurseID date activity_code mins_worked region volume
H01 13 jul 2004 2 120 R 1
H01 13 jul 2004 4,5 120 R 1
H01 13 jul 2004 1 120 R 1
H01 13 jul 2004 4,7 120 R 1
H01 03 aug 2004 1,2 90 R 1
H01 03 aug 2004 3.6 90 R 1
H02 15 jul 2004 1,4 120 M 0

with mins_worked being the total of the duration worked for by each nurse on different activities (as shown under activity_code). What I'm trying to do is to present the average number of mins_worked for each nurseID on a specific date. I tried to do this with -
Code:
bysort nurseID date: egen Mean = mean(mins_worked)

but it provides me with a mean for each group (nurseID date) instead of averaging across the unique values of mins_worked over nurseID and date. For the small data table presented above, the answer I'd like to get is (120+90+120)/3=110. I'd also like to present the average mins_worked over different identifiers such as region and volume.

Thanks!