[EpiData-list] How to count the number of missing values in an observation/record/row

epidata-list at lists.umanitoba.ca epidata-list at lists.umanitoba.ca
Thu Jun 13 07:44:26 CDT 2013


I assume you are doing this in Analysis. The solution is similar for a .chk file, but the syntax is different. It is also a bit tricky doing this in a .chk file because values can be changed after the calculation is done if you are not careful.

* c is count of non-missing variables
* s is sum of non-missing variables
* score is final score (average of non-missing variables)

gen c=0
gen s=0
if var1 <> . then c=c+1
if var1 <> . then s=s+var1
if var2 <> . then c=c+1
if var2 <> . then s=s+var2
if var3 <> . then c=c+1
if var3 <> . then s=s+var3
if var4 <> . then c=c+1
if var4 <> . then s=s+var4
if var5 <> . then c=c+1
if var5 <> . then s=s+var5
gen score = s/c

if you do not have any defined missing values, you can also calculate c this way:

c = 5-mv(var1)-mv(var2)-mv(var3)-mv(var4)-mv(var5)

and you can also calculate s this way:

s=iif(var1<>. , var1,0)+iif(var2<>. , var2,0)+iif(var3<>. , var3,0)+iif(var4<>. , var4,0)+iif(var5<>. , var5,0)

Check the help for these functions to see how they work: mv() and iif()

Jamie

On 2013-06-13, at 3:39 AM, epidata-list at lists.umanitoba.ca wrote:

> 
> Details of my problem:
> 
> My checklist contains 5 variables. Each variable is given a score (0,1,2),
> but in some records, a few variables are left blank because they are not
> relevant. The final score is calculated by dividing the sum of score of
> each variable (don't take the missing into account) by the 'total number of
> entered variables'.
> id     var1    var2    var3  var4    var5
> 1        2                 1      1        0          final score =
> (2+1+1+0)/4   ( I use the command 'ignoremissing' to get the sum)
> 2        2        2       2      1        1          final score =
> (2+2+2+1+1)/5
> 3                 1        1                           final score=(1+1)/2



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