263009 Comparing zip code tabulation area to census tract measures of poverty among high-risk heterosexuals in low income areas - 23 U.S. cities, 2006-2007

Tuesday, October 30, 2012 : 8:50 AM - 9:05 AM

Nevin Krishna, MS, MPH , Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, Atlanta, GA
Matthew John Page , School of Public Health, Emory University, Atlanta, GA
Elizabeth DiNenno, PhD , Centers for Disease Control and Prevention, Atlanta, GA
Teresa Finlayson, PhD , Division of HIV/AIDS Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, Centers for Disease Control and Prevention, Atlanta, GA
Background: Collecting census tract (CT) data can provide linkage to socioeconomic information. Since most people do not know their CTs, we assessed the comparability of Zip Code Tabulation Areas (ZCTAs) and CT poverty measures. ZCTAs use zip code (ZC) to link census data. To make this comparison, we used data from 2006-2007 National HIV Behavioral Surveillance System (NHBS) cycle among heterosexuals.

Methods: We linked poverty data from Census 2000 using ZC and CT to interviews of NHBS participants in high poverty areas within 23 cities. The analysis was restricted to participants who reported sex with someone of the opposite sex in the past year and provided valid ZC and CT data obtained using maps. Mean percentages across sites and Pearson's correlation coefficients are presented.

Results: Overall, 16,831 records met our inclusion criteria. The total mean percentage of individuals living below poverty was 33% using CT and 28% using ZC (mean difference=5.5 [SD=4.0]). Across participating cities, the percentage living below poverty ranged from 15% to 50% using CT and 13% to 40% using ZC. The mean difference between the two methods by city ranged from 2% to 18%. Overall, the two methods were strongly correlated (r=0.67, P<0.001), but varied widely by city (range: r=0.24, P<0.001 to r=0.73, P<0.001). Conclusions: Agreement between ZCTA and CT poverty measures across 23 cities was strong. However, considerable variation exists across cities. We recommend that ZCTA measures be used for aggregate city analyses but caution should be used if analyses are limited to individual cities.

Learning Areas:
Social and behavioral sciences

Learning Objectives:
1) Discuss how US census data can be used in conjunction with survey data. 2) Identify the differences between census tracts and zip code tabulation areas. 3) Assess the adequacy of zip code tabulation areas as a proxy for census tracts when measuring poverty.

Keywords: Data/Surveillance, Poverty

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: I am an Epidemiologist at the Centers for Disease Control and Prevention. I work specifically in the Behavioral and Clinical Surveillance Branch within NCHHSTP. My interests are data management and analysis, and integrating public sources of data with CDC surveys.
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.