Urban Scaling of Health Outcomes: a Scoping Review

Abstract

Urban scaling is a framework that describes how city-level characteristics scale with variations in city size. This scoping review mapped the existing evidence on the urban scaling of health outcomes to identify gaps and inform future research. Using a structured search strategy, we identified and reviewed a total of 102 studies, a majority set in high-income countries using diverse city definitions. We found several historical studies that examined the dynamic relationships between city size and mortality occurring during the nineteenth and early twentieth centuries. In more recent years, we documented heterogeneity in the relation between city size and health. Measles and influenza are influenced by city size in conjunction with other factors like geographic proximity, while STIs, HIV, and dengue tend to occur more frequently in larger cities. NCDs showed a heterogeneous pattern that depends on the specific outcome and context. Homicides and other crimes are more common in larger cities, suicides are more common in smaller cities, and traffic-related injuries show a less clear pattern that differs by context and type of injury. Future research should aim to understand the consequences of urban growth on health outcomes in low- and middle-income countries, capitalize on longitudinal designs, systematically adjust for covariates, and examine the implications of using different city definitions.

Exploring inequalities in life expectancy and lifespan variation by race/ethnicity and urbanicity in the United States: 1990 to 2019

“…Our findings of the rural penalty in longevity and lifespan variation may reflect differences in individual, structural, and contextual determinants of health between metropolitan and nonmetropolitan areas ( McCulley et al, 2022 ). Behaviors such as smoking and lack of leisure-time physical activity are more common among nonmetropolitan residents than metropolitan residents ( Eberhardt & Pamuk, 2004 ; McCulley et al, 2022 ).…”

“…Our findings of the rural penalty in longevity and lifespan variation may reflect differences in individual, structural, and contextual determinants of health between metropolitan and nonmetropolitan areas ( McCulley et al, 2022 ). Behaviors such as smoking and lack of leisure-time physical activity are more common among nonmetropolitan residents than metropolitan residents ( Eberhardt & Pamuk, 2004 ; McCulley et al, 2022 ). Regarding structural and contextual determinants, poverty is higher in nonmetropolitan areas ( U.S. Economic Research Service, 2021 ) and nonmetropolitan areas have lower access to healthcare ( Cosby et al, 2008 ) and lower standards of care ( Cossman et al, 2010 ) that put their residents at higher mortality risks.…”

The Role of Functional Urban Areas in the Spread of COVID-19 Omicron (Northern Spain)

“…Therefore, we cannot contrast properly our results with other research about health spatial patterns on FUAs. Nevertheless, there is evidence about the role of urban scaling in health outcomes, not only size, but also proximity and mobility among urban areas, as FUAs [ 50 ]. Urban and metropolitan areas are essential in tackling the pandemic, and the spread in dynamic urban areas, such as FUAs, as key areas to analyze the spatial behavior of the virus at regional and local scale [ 51 , 52 ].…”

Urban scaling of firearm violence, ownership and accessibility in the United States

“…As we have seen during the COVID-19 pandemic, social interactions in cities are also a vector to support the propagation of infectious diseases 8 , leading to superlinear scaling of incidence with population 9 . To a less understood extent, there is also evidence of superlinear scaling of crime in cities 10 .…”