Research Methodology to Examine Disparities in Communication Disorders in Underrepresented and Vulnerable Populations

Introduction

Many Americans do not reap the benefits of good health despite the United States (US) being a world leader in advances in healthcare and the provision of state-of-the-art care for most medical conditions. There are many individuals who are more “vulnerable” to disease and disability results in worse clinical and health-related outcomes. These individuals operationally defined as “vulnerable populations” live in disadvantaged communities that typically report worse health-related outcomes than other communities (Shivayogi, 2013). A range of sociodemographic factors have been identified as critical to understanding the make-up of vulnerable population and these include race/ethnicity, economic disadvantage, residence (rural vs urban) sex/gender identity and incarceration. Individuals with these sociodemographic characteristics are most likely to experience negative health-related outcomes. Therefore, these among other factors should be carefully considered when studying clinical outcomes that are at risk of the influences of health disparities in CSD.

Consequently, the aforementioned populations suffer from health disparities or an “avoidable difference in health or in important influences on health that can be shaped by policies; it is a difference in which a disadvantaged social group or groups (such as the poor, racial/ethnic minorities, women, or other groups who have persistently experienced social disadvantage or discrimination in the past) systematically experience worse health or greater health risks than the most advantaged social groups (Braveman, 2006, p.180). Therefore, disparities research involves elucidating mechanisms that contribute to observed outcomes, understanding the interactions among these mechanisms, and explaining how these mechanisms differentially impact various population subgroups. Research methodology examining disparities in underrepresented and marginalized populations involves significant definitional and methodological challenges. Proper research requires adherence to several key conceptual and definitional issues. It is important to note that disparities are not simply differences. The term disparity may connote a difference that is inequitable, unjust, or unacceptable (Krieger, 2005; Whitehead, 1992). Characterization of a difference as unjust requires a detailed understanding of the nature and etiology of the difference and is likely to involve multiple criteria such as avoidability, mutability, and detriment to groups that are disadvantaged in terms of opportunities and access to resources (Braveman and Gruskin, 2003). The term “health disparities” is, however, widely used to describe differences in health status without necessarily implying the presence of injustice (Thomson et al. 2006).

Health disparities have been reported in CSD. Studies have shown health disparities in the areas of aphasia (Ellis, Hardy, Lindrooth, et al., 2016; Hardy, Lindrooth, et al., 2018; Rogalaski, Rademaker, & Weintraub, 2007; Sharma, Briley, Wright, et al., 2019; Wallentin, 2018), dysphagia (Bussell & Gonzalez-Fernandez, 2011), mild cognitive impairment/cognitive decline (Lee, Richardson, Black, Shore, et al., 2012; Weuve, Barnes, Mendes de Leon, et al., 2018) and hearing healthcare (Nieman, Marrone, Szanton, et al., 2016). Consequently, health disparities are not new to the field yet the study of the contribution of health disparities to clinical outcomes has been limited. A key goal of this chapter is to provide CSD researchers with the necessary definitions, concepts, frameworks and research design approaches to address the many factors that contribute to health disparities while also preserving the core elements of the stellar research that currently exists in the field.