Tree cover shows an inverse relationship with depressive symptoms in elderly residents living in U.S. nursing homes

Abstract

People who live near more greenspace report less anxiety and depression. Do these findings hold for elderly populations living in care facilities, such as nursing homes? The answer to this question has not been directly examined. Studies on the relationship between greenspace and mental health in this population have focused on nature-based therapy programs rather than on greenspace coverage. Research on outdoor greenspace coverage is important for facility design. Facilities should know whether to prioritize greening investments in indoor atriums where programming can be provided year-round or in outdoor greenspace, which can also promote health by providing restorative views and reducing harmful exposures (e.g., noise and air pollution). To investigate whether nursing homes residents benefit from outdoor greenspace cover, we examined the relationship between tree canopy cover around 9186 U.S. nursing homes and the percentage of residents suffering from depressive symptoms. Depressive symptoms data were obtained from the 2011 Minimum Data Set, and canopy data were obtained from the 2011 National Land Cover Database. Because facilities with more resources and higher qualities of care might also have more trees, we gathered 2011 data on occupancy rates, staffing ratios, age, sex, percent Medicaid eligibility, care needs, for-profit status, presence of special care units from the Long Term Care Focus dataset as well as air quality and population density and used these potential covariates in adjusted generalized linear mixed models and spatial lag models. We observed an inverse relationship between depressive symptoms and tree cover surrounding facilities. Associations did not vary by aggregated racial or socioeconomic characteristics of residents but did became weaker at greater distances from facilities. These findings provide hypotheses for future testing regarding whether nursing homes should incorporate outdoor greening in addition to nature-based therapy programs for residents’ mental health.