Table of Contents

Component Description

In NHANES 2009-2010, a weighted pooled-sample design was implemented to facilitate pooling samples before making analytical measurements for specific environmental chemicals. Pooling samples allows for larger sample volumes which can result in lower limits of detection and reduces the number of measurements and costs. Laboratory components analyzed with the pooled-sample design in the NHANES 2009-2010 cycle includes:

• Brominated Flame Retardants (BFRPOL_F)
• Non-dioxin-like Polychlorinated Biphenyls & Mono-ortho-substituted Polychlorinated Biphenyls (PCBPOL_F)
• Polychlorinated Dibenzo-p-dioxins, Dibenzofurans & Coplanar Polychlorinated Biphenyls (DOXPOL_F)
• Serum Pesticides - Organochlorine Pesticides (PSTPOL_F)

The analytic pools were prepared from serum collected from a random one-third subset of the NHANES 2009-2010 participants aged 12 years and older. Samples were pooled based on gender, race and Hispanic origin, and age. This Pooled-Sample Technical Support file (POOLTF_F) contains information on individual participants included in each pool. Three variables are included in the technical support file:

SEQN - Respondent sequence number, the unique survey participant identifier that can be used to link to the other NHANES data files;

SAMPLEID - Pool identification number, indicating which pool the participant was designated to; this is the key variable corresponding to the pooled-sample laboratory component datasets;

WTSA2YRA - The adjusted subsample weight for the individual survey participant.

If a survey participant was selected as part of the one-third subsample but did not provide a serum specimen or a specimen with sufficient volume for the analyses, he/she would not be assigned to a pool. The survey participant will be coded with “SAMPLEID=.” and “WTSA2YRA=0”. In NHANES 2009-2010, there are 2524 individuals selected into the one-third subsample, and among them, 2322 provided sufficient volume of analytic specimen. Their specimens were used to create 301 pools with 2-8 samples per pool.

Please refer to the documentations accompanying each laboratory components using the pooled-sample design for more details on rationale and methods used to create pooled results.

Codebook and Frequencies

SEQN - Respondent sequence number

Variable Name:
SEQN
SAS Label:
Respondent sequence number
English Text:
Respondent sequence number.
Target:
Both males and females 12 YEARS - 150 YEARS

SAMPLEID - Pool identification number

Variable Name:
SAMPLEID
SAS Label:
Pool identification number
English Text:
Pool identification number
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 to 303 Range of Values 2322 2322
. Missing 202 2524

WTSA2YRA - Adjusted subsample weight

Variable Name:
WTSA2YRA
SAS Label:
Adjusted subsample weight
English Text:
Adjusted subsample weight for the individual participant in pooled sample
Target:
Both males and females 12 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 537270.45707 Range of Values 2524 2524
. Missing 0 2524