ABSTRACT
OBJECTIVE: Sleep is pivotal to health, wellbeing and functioning in daily life, but sleep difficulties are common and may be affected by modifiable qualities in the residential surrounding environment, in terms of greenspace. However, population-based studies on individual-level greenspace and sleep are limited. The objective of the current study was thus to investigate prospective associations between fine-grained individual-level residential greenspace and sleep, and moderating effects of life style (physical activity, work status) and sex, in a nationwide population-based Swedish cohort. METHODS: Participants of the Swedish Longitudinal Occupational Survey of Health (SLOSH)-a population-based sample of adults in Sweden-were studied during 2014-2018 (19,375 individuals; 43,062 observations). Residential greenspace land cover, and coherent green area size, were assessed via high resolution geographic information systems, at 50, 100, 300, 500 and 1000 m buffers around residences. Prospective greenspace and sleep associations were assessed via multilevel general linear models, adjusting for demographic, socioeconomic (individual and neighborhood), life style and urban factors. RESULTS: Higher greenspace availability in the immediate residential surroundings (50 m and 100 m buffer zones) was associated with less sleep difficulties, even after adjustment for confounders. Greenspace effects were generally greater among non-working individuals. Among the physically active, and among non-working, greenspace and green area size further away from home (300, 500 and 1000 m, i.e. dependent on mobility) were also associated with less sleep difficulties. CONCLUSIONS: Residential greenspace in the immediate residential surroundings is associated with significantly less sleep difficulties. Greenspace further away from home was associated with better sleep especially among the physically active, and non-working individuals. The results highlight the importance of greenspace in the immediate residential-surrounding environment for sleep, and the need to integrate health and environmental policies, urban planning and greening.
