af2a44c6_l__Variance_Estimation__Task_3_SUDAAN_proc_descript_procedure_Explanation
[Statements] SUBPOPN riagendr=2 and ridageyr > 19 and ridageyr < 60 ; [Explanation] 
Use a subpopn statement to subset on the subgroup of interest. In this example, it is females (riagendr=2) between ages 20-59 years (ridageyr > 19 and ridageyr < 60).
Continuous NHANES Web Tutorial: Variance Estimation: Task 3
Explanation