A systematic review of the modifiable areal unit problem (MAUP) in community food environmental research

AbstractGeospatial models can facilitate the delineation of food access patterns, which is particularly relevant for urban planning and health policymaking. Because community food environmental studies use different analysis units or study scales, the rigor and consistency of their evaluations cannot be ensured. This issue is known as the modifiable areal unit problem (MAUP). The paper provides a systematic review of past literature on place-based community food environmental research using different analysis units or geospatial models as they pertain to the MAUP. We identify these key findings: (1) the ZIP code zone is not recommended as an appropriate analysis unit for modeling community food access, as it did not have significant correlations with health indicators; (2) using a circular buffer of less than 0.5 km around household locations is most likely to reveal health correlations, compared with network buffers or container-based measures; (3) to reveal health effects of the community food environment, it is recommended to focus in selected regions or partitions of a study area with similar socioeconomic statuses, such as the central city or low socioeconomic status areas; (4) for studies utilizing a single statistical unit or distance measure, it is suggested to discuss the existence of the MAUP, such as evaluating the sensitivity of the model to the change of the unit or the distance measure. By highlighting the MAUP, this paper has policy implications—given that geospatial modeling of food accessibility provides support for health policy intervention, using different metrics may lead to different interpretations of health disparities and could thus misinform policy decisions. Therefore, any assessment of community food environments that may potentially lead to a policy change should consider the effects of the MAUP.