Multilevel models can be reliably estimated with an average of only five observations per group. Disaggregated techniques carry an increased risk of Type I error, even in situations where there is only limited clustering in the data.

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Over the last two decades, the impact of community characteristics on the physical and mental health of residents has emerged as an important frontier of research in population health and health disparities. However, the development and evaluation of measures to capture community characteristics is still at a relatively early stage. The purpose of this work was to assess the reliability of a neighborhood audit instrument administered in the city of Chicago using Google Street View by comparing these "virtual" data to those obtained from an identical instrument administered "in person". We find that a virtual audit instrument can provide reliable indicators of recreational facilities, the local food environment, and general land use. However, caution should be exercised when trying to gather more finely detailed observations. Using the Internet to conduct a neighborhood audit has the potential to significantly reduce the costs of collecting data objectively and unobtrusively.

Results highlight the importance of social status and socio-economic resources for maintaining optimal weight. Yet, even those in advantaged social positions have experienced an increase in BMI in recent years.

Research on the effects of the built environment in the pathway from impairment to disability has been largely absent. Using data from the Chicago Community Adult Health Study (2001-2003), the authors examined the effect of built environment characteristics on mobility disability among adults aged 45 or more years (n = 1,195) according to their level of lower extremity physical impairment. Built environment characteristics were assessed by using systematic social observation to independently rate street and sidewalk quality in the block surrounding each respondent's residence in the city of Chicago (Illinois). Using multinomial logistic regression, the authors found that street conditions had no effect on outdoor mobility among adults with only mild or no physical impairment. However, among adults with more severe impairment in neuromuscular and movement-related functions, the difference in the odd ratios for reporting severe mobility disability was over four times greater when at least one street was in fair or poor condition (characterized by cracks, potholes, or broken curbs). When all streets were in good condition, the odds of reporting mobility disability were attenuated in those with lower extremity impairment. If street quality could be improved, even somewhat, for those adults at greatest risk for disability in outdoor mobility, the disablement process could be slowed or even reversed.

The Disablement Process model explicates the transition from health conditions to disability and specifically emphasizes the role of intervening factors that speed up or slow down the pathway between pathology and disability. We used hierarchical Poisson regression analyses with data on older adults from central North Carolina to examine the role of the built environment as a modifying factor in the pathway between lower extremity functional limitations and activities of daily living. We found that, despite declining physical function, older adults report greater independence in instrumental activities when they live in environments with more land-use diversity. Independence in self-care activities is modified by housing density, in part through the effect of substandard and inadequate housing.

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Background Existing research has found a positive association between cognitive function and residence in a socioeconomically advantaged neighborhood. Yet, the mechanisms underlying this relationship have not been empirically investigated. This study tests the hypothesis that neighborhood socioeconomic structure is related to cognitive function partly through the availability of neighborhood physical and social resources (e.g. recreational facilities, community centers and libraries), which promote cognitively beneficial activities such as exercise and social integration. Methods Using data from a representative survey of community-dwelling adults in the City of Chicago (N = 949 adults age 50 and over) we assessed cognitive function with a modified version of the Telephone Interview for Cognitive Status (TICS) instrument. Neighborhood socioeconomic structure was derived from US Census indicators. Systematic Social Observation was used to directly document the presence of neighborhood resources on the blocks surrounding each respondent’s residence. Results Using multilevel linear regression, residence in an affluent neighborhood had a net positive effect on cognitive function after adjusting for individual risk factors. For white respondents, the effects of neighborhood affluence operated in part through a greater density of institutional resources (e.g. community centers) that promote cognitively beneficial activities such as physical activity. Stable residence in an elderly neighborhood was associated with higher cognitive function (potentially due to greater opportunities for social interaction with peers), but long term exposure to such neighborhoods was negatively related to cognition. Conclusions Neighborhood resources have the potential to promote “cognitive reserve” for adults who are aging in place in an urban setting.