Linkage of the National Health Interview Survey to air quality data.
OBJECTIVE
This report describes the linkage between the National Health Interview Survey (NHIS) and air monitoring data from the U.S. Environmental Protection Agency (EPA). There have been few linkages of these data sources, partly because of restrictions on releasing geographic detail from NHIS on public-use files in order to protect participant confidentiality.


METHODS
Pollution exposures for NHIS respondents were calculated by averaging the annual average exposure estimates from EPA air monitors both within 5, 10, 15, and 20 miles of the respondent's block-group location (which is available on restricted NHIS data files) and by county of residence. The 1987-2005 linked data files--referred to as NHIS-EPAAnnualAir--were used to describe the percentage of NHIS respondents linked and the median exposures by linkage method, survey year, and pollutant. Using the 2005 NHIS-EPAAnnualAir data file, the percentage linked and median exposure were described by respondent characteristics, linkage method, and pollutant.


RESULTS
Many decisions were made to define pollution exposures for NHIS respondents, including monitor selection, location assignment for NHIS respondents, and geographic linkage criteria. Geographic linkage criteria for assigning area-level exposure estimates affected the percentage and composition of respondents included in the resulting linked sample. Median exposure estimates, however, were similar among geographic linkage methods.


CONCLUSIONS
NHIS-EPAAnnualAir data files for 1985 through 2005 are currently available to users in the NCHS Research Data Center.
Parker
Jennifer D
JD
U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, Office of Analysis and Epidemiology, USA.
Kravets
Nataliya
N
Woodruff
Tracey J
TJ
D000328:Adult; D000368:Aged; D000397:Air Pollution / Q000032:analysis*; D004781:Environmental Exposure / Q000032:analysis; D004784:Environmental Monitoring / Q000379:methods*; D005260:Female; D006306:Health Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D014481:United States; D014484:United States Environmental Protection Agency