Coding the Everyday Discrimination Scale: implications for exposure assessment and associations with hypertension and depression among a cross section of mid-life African American women

Abstract

BackgroundStudies suggest that racial discrimination impacts health via biological dysregulation due to continual adaptation to chronic psychosocial stress. Therefore, quantifying chronicity is critical for operationalising the relevant aetiological exposure and hence maximising internal validity. Using one of the most common discrimination scales in the epidemiological literature, we develop a novel approach for more accurately assessing chronicity and compare it with conventional approaches to determine whether coding influences differential exposure classification and associations with hypertension and depression among African American women.MethodsData are from a socioeconomically diverse cross section of 208 mid-life African American women in Northern California (data collection: 2012–2013). Racial discrimination was assessed using the Everyday Discrimination Scale (α=0.95), and was coded using two conventional approaches: (1) situation-based coding: number of different situations ever experienced; (2) frequency-based coding: sum of Likert scale responses ranging from 'never' to 'almost everyday'; and (3) a new chronicity-based coding approach: sum of responses, weighted to capture annual chronicity (eg, ‘a few times a month’=3×12=36×/year). Outcomes are hypertension and depressive symptomatology (10-item Center for Epidemiologic Studies-Depression Scale).FindingsExposure classification differed by coding approach, by up to 41%. There was a positive association between racial discrimination and hypertension prevalence for chronicity coding only (prevalence ratio=1.61, 95% CI 1.03 to 2.49). For depressive symptoms, a dose–response relationship of similar magnitude was observed for all three coding approaches.ConclusionScale coding is an important methodological consideration for valid exposure assessment in epidemiological research. Coding can impact exposure classification and associations with important indicators of African American women’s mental and physical health.

Everyday Racial Discrimination and Hypertension among Midlife African American Women: Disentangling the Role of Active Coping Dispositions versus Active Coping Behaviors

“…The rationale for creating these categories was twofold: first, to preserve the qualitatively meaningful, time-bound structure of the original scale (e.g., yearly, monthly, daily); second, to capture potentially differential associations with hypertension among those experiencing varying levels of racial discrimination chronicity (e.g., on a yearly versus daily basis) without imposing a specific functional form (e.g., linear, quadratic) on the relationship between racial discrimination and hypertension prevalence. Our approach is consistent with previous studies that used a categorical classification of racial discrimination and showed varying patterns of association with health outcomes among African Americans [36,43,46,47,48].…”

“…Because racial discrimination is believed to impact hypertension through repeated biological adaptation to chronic psychosocial stress [10,27], precisely and accurately measuring the chronicity of these experiences was important for valid exposure assessment in this study [36]. A recent study compared three different approaches to coding the EDS, finding that conventional coding schemes may fail to fully quantify the chronicity of racial discrimination, leading to exposure misclassification and an underestimation of associations with hypertension among African American women [36].…”

“…Because racial discrimination is believed to impact hypertension through repeated biological adaptation to chronic psychosocial stress [10,27], precisely and accurately measuring the chronicity of these experiences was important for valid exposure assessment in this study [36]. A recent study compared three different approaches to coding the EDS, finding that conventional coding schemes may fail to fully quantify the chronicity of racial discrimination, leading to exposure misclassification and an underestimation of associations with hypertension among African American women [36]. Therefore, following prior work, we weighted each EDS survey item to more accurately reflect the chronicity of experiences on a yearly scale: never = 0, less than once a year = 0.5 times per year (x/year), a few times a year = 3 x/year, a few times a month = 3 x 12 months = 36 x/year, at least once a week = 2 x 52 weeks = 104 x/year, and almost every day = 5 x 52 weeks = 260 x/year (Table 1) [36].…”

“…A recent study compared three different approaches to coding the EDS, finding that conventional coding schemes may fail to fully quantify the chronicity of racial discrimination, leading to exposure misclassification and an underestimation of associations with hypertension among African American women [36]. Therefore, following prior work, we weighted each EDS survey item to more accurately reflect the chronicity of experiences on a yearly scale: never = 0, less than once a year = 0.5 times per year (x/year), a few times a year = 3 x/year, a few times a month = 3 x 12 months = 36 x/year, at least once a week = 2 x 52 weeks = 104 x/year, and almost every day = 5 x 52 weeks = 260 x/year (Table 1) [36]. Recoded items were summed to generate a score ranging from 0–2600, representing the total annual number of EDS experiences across ten situations.…”

“…However, despite what we know about the stressfulness of racial discrimination, and the role of stress in the pathogenesis of hypertension, findings of an association between self-reported discrimination and myriad cardiovascular indicators are mixed [23,25,26,28,29,30]. Some studies have demonstrated evidence of associations between general or racial discrimination and various cardiovascular outcomes among African Americans, including high blood pressure or hypertension [31,32,33,34,35,36], increased cardiovascular reactivity [37,38,39,40], and lower nocturnal blood pressure dipping [41], whereas others have shown null effects [24,42,43,44,45]. Moreover, rather than consistently showing a linear or dose-response relationship, previous literature has illustrated distinctive patterns of association between frequency of racial discrimination and cardiovascular and other stress-related outcomes among African Americans (e.g., J-shaped, U-shaped, inverse U-shaped, M-shaped) [34,35,36,43,46,47,48,49].…”