ZIP Code and ZIP Code Tabulation Area Linkage: Implications for Bias in Epidemiologic Research.

ABSTRACT:

Background

To our knowledge, no agreed-upon best practices exist for joining U.S. Census ZIP Code Tabulation Areas (ZCTAs) and U.S. Postal Service ZIP Codes (ZIPs). One-to-one linkage using 5-digit ZCTA identifiers excludes ZIPs without direct matches. "Crosswalk" linkage may match a ZCTA to multiple ZIPs, avoiding losses.

Methods

We compared noncrosswalk and crosswalk linkages nationally and for mortality and health insurance in California. To elucidate selection implications, generalized additive models related sociodemographics to whether ZCTAs contained nonmatching ZIPs.

Results

Nationwide, 15% of ZCTAs had nonmatching ZIPs, i.e., ZIPs dropped under noncrosswalk linkage. ZCTAs with nonmatching ZIPs were positively associated with metropolitan core location, lower

SUBMITTER: Chen F 

PROVIDER: S-EPMC12341766 | biostudies-literature | 2025 Jan

REPOSITORIES: biostudies-literature