Exploring the association between income inequality and sleep in Canadian adolescents: A path analysis approach.

OBJECTIVES: An estimated 30% of Canadian adolescents do not get the recommended 8-10hours of sleep. No prior study has examined the role of income inequality, the gap between rich and poor within a society, in adolescent sleep. The aim of this study is to examine the association between income inequality and sleep duration among Canadian adolescents, how this association differs by gender, and whether depressive symptoms, anxiety, and social cohesion mediate this relationship.

METHODS: Multilevel path models were conducted using cross-sectional survey data from 74,501 adolescents who participated in the Cannabis, Obesity, Mental health, Physical activity, Alcohol use, Smoking, and Sedentary behavior (COMPASS) study in 2018-2019. Income inequality was measured at the census division level and sleep duration, gender, depressive symptoms, anxiety, and social cohesion were measured at the individual level.

RESULTS: A 1% increase in income inequality was associated with a 3.67-minute decrease in sleep duration (95% CI=-5.64 to -1.70). The cross-level interactions between income inequality and gender were significant, suggesting that income inequality has more adverse associations with sleep among females than males. Both depressive symptoms and anxiety were significant mediators, wherein greater income inequality was associated with higher levels of depressive symptoms and anxiety, which were in turn, associated with a shorter sleep duration.

CONCLUSION: Interventions that reduce income inequality may prevent depressive symptoms and anxiety and improve sleep in adolescents. Reducing societal income gaps may improve adolescent sleep especially in those attending school in high income inequality areas, females, and those experiencing depressive symptoms and anxiety.