missing data in agecat

missing data in agecat

by Christine -
Number of replies: 1

Hi again,

I'm with some folks doing homework and we made a last category in agecat

recode agecat .=9

 

HOWEVER,

. tab agecat

patient age |
in years |
categories | Freq. Percent Cum.
------------+-----------------------------------
2 | 3 1.67 1.67
3 | 21 11.67 13.33
4 | 28 15.56 28.89
5 | 67 37.22 66.11
6 | 45 25.00 91.11
7 | 9 5.00 96.11
8 | 3 1.67 97.78
9 | 4 2.22 100.00
------------+-----------------------------------
Total | 180 100.00

 

BUT

bysort agecat: sum age 

at the end:

-> agecat = 9

Variable | Obs Mean Std. Dev. Min Max
-------------+--------------------------------------------------------
age | 0

 

Any suggestions?  Why are the 4 observations with age category 9 under the command from tab agecat not showing up with the bysort?

Chris

In reply to Christine

Re: missing data in agecat

by Bardia -

I think this is related to the nature of the "summarize" command. It can't handle non-numeric data, including missing data. if you do "tab agecat ,missing", you'll see 4 patients with missing categorized age.