Residential Surrounding Greenness, Self-rated Health and Associations with Neighborhood Satisfaction and Social Capital

Background: Previous research suggests that green environments positively influence health. Several underlying mechanisms have been discussed; one of them is facilitation of social interaction. Further, greener neighborhoods are likely perceived more esthetic which contributes to satisfaction and well-being.

Objective: To analyze the association of residential greenness with self-rated health, and to explore their relationships with neighborhood satisfaction and neighborhood social capital.

Methods: We analyzed baseline data of 4,480 participants from the population-based Heinz Nixdorf Recall study (age 45 – 75 years). Greenness within 100 m around participants' residence was defined by the Normalized Difference Vegetation Index (NDVI, range: 0 – 1), which was calculated from satellite imagery. Self-rated health in the past 12 months was obtained via standardized interview and categorized into 'very good/good/fair' and 'poor/very poor'. Satisfaction with neighborhood was assessed by questionnaire and dichotomized into 'very unsatisfied/rather unsatisfied' and 'rather satisfied/very satisfied'. Neighborhood social capital was categorized as high if participants fully agreed/rather agreed (vs fully disagreed/rather disagreed) with the statements “Most people in my neighborhood are helpful” and “I can trust most people in my neighborhood”. We estimated odds ratios (OR) and 95% confidence intervals (95% CI), adjusted for age, sex, employment status, neighborhood unemployment, household size, smoking, BMI and physical activity.

Results: Prevalence of poor self-rated health was 16.4% (men 13.1%, women 19.8%), mean 100 m-NDVI was 0.36 (range 0.02 – 0.66). With increasing NDVI, poor self-rated health decreased by 10% (adjusted OR 0.90, 95% CI 0.82 – 0.98; per interquartile range [0.1] increase). Further, NDVI was positively associated with neighborhood satisfaction (1.40, 1.23 – 1.61) and high neighborhood social capital (1.22, 1.12 – 1.33). On the other side, poor self-rated health was negatively associated with neighborhood satisfaction (0.70, 0.52 – 0.94) and neighborhood social capital (0.53, 0.44 – 0.64).

Conclusion: Our results suggest a beneficial effect of residential greenness on self-rated health. Further, greenness was associated with higher neighborhood satisfaction and social capital, which were also associated with better self-rated health. Owing to the cross-sectional design, the direction of these associations cannot be inferred with certainty. The complex interrelations of the social and built environment with health need to be further evaluated to enable health-promoting urban development strategies.