Svyset was used. The independent variables are the socio-demographic and other variables like exposure to family planning messages. The dependent variable is "modern contraceptive use".

On using the "svy, subpop ( ), tab" command to analyze the two age groups separately, some of the cells become either 0 or lower than 5.

Variable --> v013 - 15-19 = 1

- 20-24 = 2

Questions

1. The cells with 0 observations showed a message "Table contains a zero in the marginals. Statistics cannot be computed". I used the command "svy if v013==1, tab" command and the 0 disappeared. The proportions and confidence interval are the same but I got the p-value. However, is it recommended to use this command or is there an alternative?

2. Some cells have observations less than 5. Usually Fisher's exact test is used in very small numbers but in this survey set, it is not compatible (I think). Is there a way to calculate them?

best regards

Kyaw]]>

It is definitely preferable to use the subpop option. However, in your situation I would use these lines:

gen v013_1=1 if v013==1 gen v013_2=1 if v013==2 svy, subpop(v013_1), tab svy, subpop(v013_2), tab

I think this will take care of the problem. In the specification of subpop you need to use an argument (what goes between the parentheses) that is 1 for v013=1 or for v013=2.

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