Race, Discrimination, and Sleep in the Midlife in the United States (MIDUS) Study

INTRODUCTION:   Racial/ethnic minorities are more likely to experience poor sleep quality than non-Hispanic whites.  Poor sleep quality is associated with poorer mental and physical health, including depression and hypertension.  Limited work has assessed the association between discrimination and sleep outcomes, and whether these associations vary by racial/ethnic group. 

METHODS:   Using data from the Midlife in the United States (MIDUS) study at Waves I and II, we examined associations between discrimination, race, and sleep quality.  Perceived discrimination was measured using the 9-item version of the Williams Everyday Discrimination Scale (EDS).  A 4-category variable was used to assess discrimination across the study period based on quartile rankings at each wave.  The analytic sample (N=1677) was classified as follows: low-stable (27.1%), decreasing (24.9%), increasing (26.4%), and high- stable (21.7%).  A 5-point Likert-like scale (1 = never, 5 = almost always) was used assess sleep quality based on the frequency of trouble falling asleep, waking in the middle of the night with trouble getting back to sleep, and waking very early with trouble getting back to sleep.  The mean of the responses was calculated, with greater values representing greater sleep difficulty (range 1-5; Cronbach’s alpha = 0.82).  

RESULTS:   Survey weighted linear regression models, controlling for sociodemographics, suggested respondents with decreasing (b=0.17, SE=0.07, p=0.01), increasing (b=0.19, SE=0.07, p<0.01), and high-stable (b=0.34, SE=0.07, p<0.01) levels of perceived discrimination had poorer sleep quality than respondents who reported consistently low discrimination.  Black (b=0.29, SE=0.13, p=0.02) and white (b=0.21, SE=0.05, p<0.01) females, but not black males, had significantly poorer sleep quality than white males, but no significant interactions between discrimination and either race or gender combinations were found.  

CONCLUSIONS:  

In light of current evidence of the negative physiologic impact of poor sleep quality, future research to better understand the psychosocial correlates of sleep quality is warranted.