Moving beyond the residential neighborhood to explore social inequalities in exposure to area-level disadvantage: Results from the Interdisciplinary Study on Inequalities in Smoking.

The focus, in place and health research, on a single, residential, context overlooks the fact that individuals are mobile and experience other settings in the course of their daily activities. Socio-economic characteristics are associated with activity patterns, as well as with the quality of places where certain groups conduct activities, i.e. their non-residential activity space. Examining how measures of exposure to resources, and inequalities thereof, compare between residential and non-residential contexts is required. Baseline data from 1890 young adults (18-25 years-old) participating in the Interdisciplinary Study of Inequalities in Smoking, Montreal, Canada (2011-2012), were analyzed. Socio-demographic and activity location data were collected using a validated, self-administered questionnaire. Area-level material deprivation was measured within 500-m road-network buffer zones around participants' residential and activity locations. Deprivation scores in the residential area and non-residential activity space were compared between social groups. Multivariate linear regression was used to estimate associations between individual- and area-level characteristics and non-residential activity space deprivation, and to explore whether these characteristics attenuated the education-deprivation association. Participants in low educational categories lived and conducted activities in more disadvantaged areas than university students/graduates. Educational inequalities in exposure to area-level deprivation were larger in the non-residential activity space than in the residential area for the least educated, but smaller for the intermediate group. Adjusting for selected covariates such as transportation resources and residential deprivation did not significantly attenuate the education-deprivation associations. Results support the existence of social isolation in residential areas and activity locations, whereby less educated individuals tend to be confined to more disadvantaged areas than their more educated counterparts. They also highlight the relevance of investigating both residential and non-residential contexts when studying inequalities in health-relevant exposures.