How can city planners improve health and reduce mortality in Alameda County, California? A cross-sectional analysis

Abstract

BackgroundDramatic disparities in a range of health outcomes persist in Alameda County, California. Age-standardised mortality rates range from 300 to 1300 deaths per 100 000 across census tracts in this county, with life expectancies lagging by 10 years in the most disadvantaged census tracts. Finding factors at the community level that affect neighbourhood health levels is a key step towards addressing these inequalities. Walking to work may be one of these factors, and is something that local policy makers could effectively act upon through city planning and maintenance initiatives. The objective of this research was to investigate the impact of walking to work on mortality at the census tract level, and to quantify the change in health inequalities that would result from increases in walking in high-mortality-risk neighbourhoods. MethodsWe analysed data from the American Community Survey at the census tract level using a linear regression model. We investigated the relation between walking to work and age-standardised all-cause mortality rates, after controlling for known determinants of health such as race, income, and occupation. We also conducted a counterfactual and risk assessment analysis to assess the expected health benefits if commuting behaviours were modified, and to determine the effect of various levels of walking on health inequalities. FindingsWalking to work was significantly and negatively associated with both cardiovascular mortality rates and all-cause mortality rates. Neighbourhoods with the highest walk-commuting percentages also had some of the lowest incomes of the available census tracts. We found that even a moderate increase in walk commuting (25% increase) can lead to measurable gains in health, with five deaths averted per 1000 deaths. InterpretationImproved neighbourhood walkability through the inclusion and maintenance of continuous sidewalks and mixed land use could play an important role in reducing existing health disparities and improving overall health outcomes. FundingNone.