Method 1 - Single Stage PSU's
Sampled With Replacement within Strata Design for 1985-1994 NHIS. For the above simplification of the NHIS sample design structure, use the following SUDAAN
PROC (procedure name) DESIGN = WR; For information about corresponding statements for other software packages (Stata, SPSS, SAS survey procedures, R, VPLX), and guidance for analyses of subgroups, refer to:
Variance Estimation for the 1985-1994 NHIS Public
Method 2 - Multistage stratified sampling design for the 1987-1994 NHIS. Prior to use of this method the following recoding must be done on the NHIS file. This example is in SAS but other programming languages may be used. If (TYPE_PSU = 1 or TYPE_PSU = 4) then do; This recode creates two new variables on each record, PSU and POPPSU, for use by SUDAAN's NEST and TOTCNT statements. For more information on the purpose of these statements refer to SUDAAN documentation. With these additional variables, use the following SUDAAN code for NHIS data-sets assuming a multistage stratified sampling design. Before running SUDAAN against the data file, however, sort the input file by the NEST variables (STRATUM, PSU, SUB, and SSU). For SUDAAN, describe the NHIS sampling design as follows:
PROC
(procedure name) DESIGN = WOR; Caution. This method assumes that ALL records on the BASIC HEALTH AND DEMOGRAPHIC (BHD) or CURRENT HEALTH TOPIC (CHT) file are being used. If, however, you keep only selected records on a file, e.g., persons aged 65+ (which may delete all records from one or more SSUs), care must be taken to preserve the integrity of the sampling design. All Self-Representing (SR) SSU's (TYPE_PSU = 1 or 4) listed on the FULL NHIS file (BHD or CHT) must have at least one representative on the data file used for input to SUDAAN. Moreover, all Nonself-representing (NSR) PSU's must have at least one record for a person on this data file. The NEST variables (STRATUM, PSU, SUB, and SSU) along with the weight variable must be on each record of the analysis file.
This page last reviewed
October 15, 2008
|