Racial disparities in disability among older adults: finding from the exploring health disparities in integrated communities study.

Although the elimination of health disparities and the prevention of disability in late life are top public health priorities (Committee on Understanding and Eliminating Racial and Ethnic Disparities in Health Care, 2002; U.S. Department of Health and Human Services, 1991), little progress has been achieved as Black older adults consistently exhibit higher rates of disability than White older adults (D. O. Clark & Maddox, 1992; Committee on Understanding and Eliminating Racial and Ethnic Disparities in Health Care, 2002; Coppin et al., 2006; Kelley-Moore & Ferraro, 2004; Kington & Smith, 1997; Koster et al., 2005; Mendes de Leon, Barnes, Bienias, Skarupski, & Evans, 2005; Schoeni, Martin, Andreski, & Freedman, 2005; Thorpe, Bell, LaVeist, & Simonsick, 2009; Thorpe, Kasper, et al., 2008; Thorpe et al., 2012). A number of explanations such as socioeconomic status (SES), health behaviors, and health status have been tested; yet, racial differences in disability persist. Because of the expected growth in the aging population, which includes a substantial increase in minorities and decrease in the number of Whites by 2050 (Federal Interagency Forum on Aging-Related Statistics, 2008), elucidating factors that underlie the racial-related inequalities in disability is paramount. Efforts to improve the understanding of racial disparities in disability are limited by two issues. First, race and SES are inextricably linked with Blacks having considerably fewer socioeconomic resources than Whites (Braveman et al., 2005; LaVeist, 2005; Thorpe, Brandon, & LaVeist, 2008; Williams & Collins, 1995). Because of this strong relationship between race and SES, the ability to determine how race and SES operate to produce disparities in disability is complicated (LaVeist, Pollack et al., 2011; LaVeist et al., 2008). Typically to address race and SES confounding, a multivariate approach is used whereby SES is included in the regression model. This is a well-recognized approach; however, it may not always be sufficient (see LaVeist, Thorpe, Mance, & Jackson, 2007, for details). The second problem in understanding racial disparities in disability is the confounding between race and residential segregation. The United States is very racially segregated; as a result, African Americans and Whites generally live in separate communities, where they have different social and environmental risk exposures. According to segregation theories such as Risk Exposure Theory and Resource Deprivation Theory (LaVeist, 2005), minority communities have social and environmental risks typically characterized by high crime (Lee, 2000) and poor housing (Black & Macinko, 2008; Williams & Collins, 2001), and are less likely to have as many health-promoting resources as White communities (Gaskin, Dinwiddie, Chan, & McCleary, 2012a, 2012b). This differential exposure to neighborhood stressors can contribute to a person’s ability to perform certain social roles and tasks. Specifically, neighborhoods that contain fewer healthy food choices, parks, sidewalks, recreational spaces, and medical facilities may negatively affect the adoption of health-promoting behaviors that can impede the progression or delay the onset of disability. Prior work examining race and disability has largely focused on individual measures such as SES (D. O. Clark, 1993; D. O. Clark & Maddox, 1992; Coppin et al., 2006; Koster et al., 2005; Liao, McGee, Cao, & Cooper, 1999; Peek, Coward, Henretta, Duncan, & Dougherty, 1997; Schoenbaum & Waidmann, 1997; Thorpe, Bowie, Wilson-Frederick, Coa, & LaVeist, 2013; Thorpe, Brandon, & LaVeist, 2008; Thorpe et al., 2012; White-Means & Hammond, 1993) or health-related factors (Kelley-Moore & Ferraro, 2004; Kington & Smith, 1997; Koster et al., 2007; Mendes de Leon, 1997). However, other investigators have sought to understand the interrelationships among key individual factors such as sex, SES, and disability (Johnson & Wolinsky, 1994; Mendes de Leon et al., 2005; Thorpe, Szanton, Bell, & Whitfield, 2013; Wray & Blaum, 2001) Findings from all of these studies highlight the importance of disentangling key confounders such as sex, SES, and health factors to advance our understanding of race differences in disability. In addition to individual-level factors, there is a growing body of literature that focuses on the association between neighborhood factors and disability (Balfour & Kaplan, 2002; Beard et al., 2009; C. R. Clark et al., 2009; Freedman, Grafova, Schoeni, & Rogowski, 2008; Glass & Balfour, 2003; Lang, Llewellyn, Langa, Wallace, & Melzer, 2008; Nordstrom et al., 2007; Pruchno, Wilson-Genderson, & Cartwright, 2012; White et al., 2010). These studies have consistently demonstrated that neighborhood indicators, including social vulnerability, wealth, violence, presence of physicians, traffic, trash, and litter, are related to disability in older adults. Also, studies assessing the impact of where one resides on race disparities in disability have found that geographic area affect disability (Lin, 2000). However, we are unaware of any study that has sought to determine whether social and environmental conditions contribute to racial differences in disability. Accounting for social context in health disparities research has demonstrated a substantial reduction or lack of racial differences in health outcomes, such as hypertension (Thorpe, Kasper, et al., 2008), obesity (Bleich, Thorpe, Sharif-Harris, Fesahazion, & LaVeist, 2010), health services use (Gaskin, Price, Brandon, & LaVeist, 2009), and diabetes (LaVeist, Thorpe, Galarraga, Bower, & Gary-Webb, 2009) in a racially integrated community without racial differences in income. This evidence suggests that social context is an important, yet understudied, determinant of health (LaVeist, Pollack et al., 2011; LaVeist et al., 2007; Williams & Collins, 2001). However, the extent to which racial disparities in disability are manifestations of differential social contexts rather than race is largely unknown. Furthermore, data sources available to disentangle race, SES, and segregation simultaneously are sparse. Thus, the purpose of this study was to examine racial disparities in disability within a sample of White and African American community-dwelling older adults living in the same social context with similar socioeconomic resources.