Average of a variable using xtsum

[Tuna Ustunkaya]

Hi I am new to the panel variables and have encountered a problem. I am using xtsum command to get the average age of patient by panel variable (which is patient ID). However, since every patient have different frequency of data I end up with mean age (accounting the different frequencies which is 67.38). However, I'd like to get mean of age without accounting for different frequencies in each patient ID - otherwise I'd like to get the real mean age of patients which is 68.78. Are there any stata commands that allow me to do that?

Thanks in advance, I put the commands that I used below.

xtsum age

Variable | Mean Std. Dev. Min Max | Observations
-----------------+--------------------------------------------+----------------
age overall | 67.38174 7.829393 52 85 | N = 2245
between | 9.028221 52 85 | n = 19
within | 0 67.38174 67.38174 | T-bar = 118.158


tab ïpatientid, sum(age)

| Summary of age
ïpatientid | Mean Std. Dev. Freq.
------------+------------------------------------
1 | 80 0 26
2 | 71 0 67
3 | 67 0 46
4 | 76 0 128
5 | 70 0 54
6 | 85 0 70
7 | 70 0 153
8 | 63 0 266
9 | 67 0 153
10 | 76 0 172
11 | 61 0 48
12 | 67 0 174
13 | 52 0 127
14 | 85 0 48
15 | 54 0 145
16 | 68 0 130
17 | 71 0 219
18 | 61 0 91
19 | 63 0 128
------------+------------------------------------
Total | 67.381737 7.8293933 2,245

display (80+71+67+76+70+85+70+63+67+76+61+67+52+85+54+68+7 1+61+63)/19
68.789474

[Clyde Schechter]

egen flag = tag(ipatientid)
summ age if flag

In the future, when showing data examples, please use the -dataex- command to do so. If you are running version 15.1 or a fully updated version 14.2, it is already part of your official Stata installation. If not, run -ssc install dataex- to get it. Either way, run -help dataex- to read the simple instructions for using it. -dataex- will save you time; it is easier and quicker than typing out tables. It includes complete information about aspects of the data that are often critical to answering your question but cannot be seen from tabular displays or screenshots. It also makes it possible for those who want to help you to create a faithful representation of your example to try out their code, which in turn makes it more likely that their answer will actually work in your data.



When asking for help with code, always show example data. When showing example data, always use -dataex-.

[Tuna Ustunkaya]

Thank you so much for your help Clyde. I will keep in mind to use dataex for the future.