Are your asset data as good as you think? Conducting a comprehensive census of built assets to improve urban population health.

Secondary data sources are widely used to measure the built asset environment, although their validity for this purpose is not well-established. Using community-engaged research methodology, this study conducted a census of public-facing, built assets via direct observation and then tested the performance of these data against widely used secondary datasets. After engaging community organizations, a community education campaign was implemented. Using web-enabled cell phones and a web-based application prepopulated with the secondary data, census workers verified, modified, and/or added assets using street-level observation, supplementing data with web searches and telephone calls. Data were uploaded to http://www.SouthSideHealth.org . Using direct observation as the criterion standard, the sensitivity of secondary datasets was calculated. Of 5,773 assets on the prepopulated list, direct observation of public-facing assets verified 1,612 as operating; another 653 operating assets were newly identified. Sensitivity of the commercial list for nonresidential, operating assets was 61 %. Using the asset census as the criterion standard, secondary datasets were incomplete and inaccurate. Comprehensive, accurate built asset data are needed to advance urban health research, inform policy, and improve individuals' access to assets.