Measurement error in studies of the built environment: validating commercial data as objective measures of neighborhood destinations.

BACKGROUND There is increasing focus on the influence of neighborhood destinations on a variety of health behaviors. Commercial databases, integrated with Geographic Information Systems (GIS), are popular sources of destination information for public health researchers. However, the suitability and accuracy of these data for public health research purposes has been generally unexplored. METHODS This study validated the presence and number of a broad range of destination types listed within an Australian-based commercial database (Yellow Pages), thought to be important for encouraging health behaviors, against those identified via field audit. The study was conducted in and around 5 housing developments within the RESIDential Environments project across metropolitan Perth, Western Australia. RESULTS Overall agreement of the count of destinations listed within the Yellow Pages ranged from 0.29-0.76, depending on the study area, the timing of the data extract and the geocoding methods used. Results also indicated considerable variation between different extracts from the same commercial dataset, and appreciable over- and under-counting of different destination types compared with field audit findings. CONCLUSIONS The choice of database and extraction time and methods, have important implications in the quantification of neighborhood destination mix and robustness of associations with public health behaviors.