Drawing on more than 14 million daily sleep records, researchers reveal how food insecurity, housing challenges, and healthcare access are linked to the amount and consistency of our sleep, highlighting the social inequalities behind a good night's rest.
Study: Social Determinants of Health and Long-Term, Device-Based Sleep Health. Image credit: WESTOCK PRODUCTIONS/Shutterstock.com
Social determinants of health, including economic stability, healthcare access, and living conditions, are significantly associated with long-term sleep duration and regularity, according to a new study published in JAMA Network Open.
Social inequalities and their links to sleep health
Sleep is a natural state characterized by changes in brain activity levels, heart rate and breathing rate, body temperature, and other physiological functions. Good-quality sleep is essential for physical, mental, and neurobehavioral well-being.
Insufficient, excessively long, or irregular sleep has been consistently linked to adverse cardiometabolic outcomes and increased mortality. Recent evidence indicates that self-reported sleep problems are becoming increasingly common in the United States. A marked sleep health disparity has also been observed across marginalized and socioeconomically diverse populations.
A growing body of research has linked social determinants of health, including economic stability, access to quality education and healthcare, living conditions, and social identity, to sleep health. However, these studies have potential limitations, including reliance on self-reported sleep duration, smaller sample sizes and shorter monitoring periods, or assessment of single domains rather than a comprehensive assessment of social determinants of health.
The current study aimed to investigate how overall and domain-specific social determinants of health are associated with long-term sleep duration and regularity monitored using a wearable device.
Wearable devices track sleep across 12,403 participants
The cross-sectional study included a total of 12,403 participants from the National Institutes of Health’s All of Us Research Program who provided at least 180 days of Fitbit wearable device-derived sleep data, including pre-enrollment historical records. Participants also completed the social determinants of health survey, which assessed four domains: social and community context, economic stability, neighborhood environment, and healthcare access and quality.
The device-estimated main sleep episodes were analyzed to calculate average daily sleep duration and day-to-day sleep duration variation (measured as the standard deviation of nightly sleep duration) across all available days. The study analyzed more than 14.3 million daily sleep records collected over a median monitoring period of 982 days, or approximately 2.7 years.
Favorable social conditions linked to longer, steadier sleep
People living in more favorable social and economic conditions tended to sleep longer and more consistently. After accounting for sociodemographic and lifestyle factors, researchers found that participants in the highest third of overall social determinants of health scores slept an average of 5.82 minutes longer per day and had 4.79 minutes less day-to-day variation in sleep duration than those in the lowest third.
Economic stability emerged as a particularly important factor in sleep health. Participants who experienced neither food nor housing insecurity slept an average of 10.70 minutes longer per day and had 8.70 minutes less variability in sleep duration than those facing both challenges.
Better healthcare access and quality were also associated with longer and more consistent sleep, while favorable social and community conditions and, to a lesser extent, better neighborhood environments were linked to greater sleep regularity.
Interestingly, social circumstances showed generally stronger and more consistent associations with how regularly people slept than with how long they slept.
Further analysis revealed that people with more favorable social conditions were less likely to sleep for fewer than six hours compared with six to eight hours. No significant association was observed with sleeping more than eight hours, although the relatively small number of participants in this category limited conclusions about longer sleep durations.
The subgroup analysis by age, sex, race, and ethnicity showed that the observed association between overall social determinants of health and sleep duration was stronger among participants aged 60 years or above compared to those aged below 60 years. These age-related differences were particularly evident for social and community context, with a similar but statistically nonsignificant trend for economic stability.
In contrast to these findings, a stronger inverse association between healthcare access and quality and sleep duration variation was observed among younger participants.
The subgroup analysis by race showed that a better neighborhood environment was associated with longer sleep duration among participants from racial minority groups, whereas no significant association was observed among White participants.
Addressing social inequalities may help improve sleep health
The study reveals that more favorable social determinants of health conditions are associated with longer sleep duration and lower day-to-day variation in sleep duration. Overall, the findings highlight the significant associations between overall and domain-specific social determinants of health and sleep health.
These findings have potential clinical implications. Shorter sleep duration and sleep irregularity have widely been linked to several chronic diseases, including cardiovascular and metabolic diseases. The negative health impact of sleep disturbance may be associated with disrupted circadian rhythms.
Rotating shift work schedules are considered to be key drivers of high day-to-day variation in sleep duration. These types of work schedules are more common among individuals with unfavorable social determinants of health, suggesting a plausible explanation for the greater sleep irregularity observed among these groups. Psychological distress and environmental disruptions, such as nighttime noise, air pollution, and artificial light at night, may also contribute to poorer sleep among socially disadvantaged individuals.
The study findings suggest that insufficient or irregular sleep may be relevant to understanding the association between social disadvantage and adverse health outcomes. Addressing adverse social and structural conditions may therefore represent an important strategy for improving sleep health and reducing health disparities.
In the All of Us Research Program, multiple device models with evolving sleep-estimating algorithms were used to collect sleep data, which might have caused measurement error. Furthermore, the study population was mostly White with higher socioeconomic status, limiting generalizability of the findings to other populations.
The study primarily focused on only two sleep characteristics and the main sleep period, excluding naps and other compensatory sleep, and therefore could not capture the full multidimensional nature of sleep health. Furthermore, complete reliance on self-reported social determinants of health measures may be subject to perception-based biases.
Future research including additional sleep domains and more diverse populations is needed for more conclusive interpretations.
Minor sleep loss increases risk of phishing scam traps