af2a44c6_l__Variance_Estimation__Task_3_SUDAAN_proc_descript_procedure_Explanation
[Statements] proc sort data =BP_analysis_Data; by sdmvstra sdmvpsu; run ; [Explanation] 
Use the SAS procedure, proc sort, to sort the data by the design parameters, strata (sdmvstra) and primary sampling units (sdmvpsu), before running the procedure in SUDAAN.