<p><strong>OBJECTIVE: </strong>To assess the utility of imputing race/ethnicity using U.S. Census race/ethnicity, residential address, and surname information compared to standard missing data methods in a pediatric cohort.</p>

<p><strong>DATA SOURCES/STUDY SETTING: </strong>Electronic health record data from 30 pediatric practices with known race/ethnicity.</p>

<p><strong>STUDY DESIGN: </strong>In a simulation experiment, we constructed dichotomous and continuous outcomes with pre-specified associations with known race/ethnicity. Bias was introduced by nonrandomly setting race/ethnicity to missing. We compared typical methods for handling missing race/ethnicity (multiple imputation alone with clinical factors, complete case analysis, indicator variables) to multiple imputation incorporating surname and address information.</p>

<p><strong>PRINCIPAL FINDINGS: </strong>Imputation using U.S. Census information reduced bias for both continuous and dichotomous outcomes.</p>

<p><strong>CONCLUSIONS: </strong>The new method reduces bias when race/ethnicity is partially, nonrandomly missing.</p>