Table of Contents

Component Description

The current National Health and Nutrition Examination Survey (NHANES) is a continuous program starting in 1999. The survey interviews and examines a nationally representative sample of 5,000 persons each year. These persons are located in counties across the country, 15 of which are visited each year. No geographic location was released in order to protect the identification of respondents for the NHANES survey. State and county information could be obtained through the Research Data Center (RDC). It is desirable, however, to use a finer level of geography to spatially analyze the NHANES data and to answer various important research questions about the effect of geography on health. Therefore, NCHS has asked HUD to geocode (i.e., assign geographic codes to) the NHANES survey data for analytical use in the RDC every two year cycle.

HUD geocoded the 2007-2008 NHANES survey data to the 2000 census.

Specifically, HUD provided:

    1. Census block group, census tract, county, state, and all other census codes normally provided by the HUD Geocoding Service Center for each residential address.
    2. Latitude and longitude for each residential address.

Analytic Notes

2007-2008 NHANES Geocoding Summary:

Input Data Records Read (All SPs): 10,149

Census 2000 RC Values Count 
"S" Street Match GCP rcds: 9,223
"9" ZIP+4 Match GCP rcds: 391
"5" ZIP Match GCP rcds: 530
Space (Nomatch) GCP rcds: 5

Census 2000 LVL Values
"R" "Rooftop" Level rcds: 9,223 
"4" ZIP+4 Level records: 70 
"B" Block Group LVL records: 321
"T" Tract Level records: 530 
"2" ZIP+2 Level records: 0
"5" ZIP5 Level records: 0
"Z" ZIP Level records: 0
Space (Nomatch) LVL records: 5

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 0 YEARS - 150 YEARS

RC2K - Census 2000 Geocoder General Return Code

Variable Name:
RC2K
SAS Label:
Census 2000 Geocoder General Return Code
English Text:
Reference census 2000 geocoder return code
Target:
Both males and females 0 YEARS - 150 YEARS

LVL2K - Census 2000 Lat/Long Geocoding Level

Variable Name:
LVL2K
SAS Label:
Census 2000 Lat/Long Geocoding Level
English Text:
Census 2000 Geocoder Lat/Long Geocoding Level
Target:
Both males and females 0 YEARS - 150 YEARS

LAT - Latitude

Variable Name:
LAT
SAS Label:
Latitude
English Text:
Latitude in decimal format with up to 6 decimal precision
Target:
Both males and females 0 YEARS - 150 YEARS

LON - Longitude

Variable Name:
LON
SAS Label:
Longitude
English Text:
Longitude in decimal format with up to 6 decimal precision
Target:
Both males and females 0 YEARS - 150 YEARS

STATE2K - Census 2000 FIPS State Code

Variable Name:
STATE2K
SAS Label:
Census 2000 FIPS State Code
English Text:
Census 2000 FIPS status code
Target:
Both males and females 0 YEARS - 150 YEARS

CNTY2K - Census 2000 FIPS County code

Variable Name:
CNTY2K
SAS Label:
Census 2000 FIPS County code
English Text:
Census 2000 FIPS County code
Target:
Both males and females 0 YEARS - 150 YEARS

TRACT2K - Census 2000 Tract

Variable Name:
TRACT2K
SAS Label:
Census 2000 Tract
English Text:
Census 2000 tract/BNA (leading zeros with the decimal point impiled)
Target:
Both males and females 0 YEARS - 150 YEARS

BG2K - Census 2000 Block Group

Variable Name:
BG2K
SAS Label:
Census 2000 Block Group
English Text:
Census 2000 block group
Target:
Both males and females 0 YEARS - 150 YEARS

BLOCK2K - Census 2000 block ID

Variable Name:
BLOCK2K
SAS Label:
Census 2000 block ID
English Text:
Census 2000 block ID - first character is the census block group
Target:
Both males and females 0 YEARS - 150 YEARS