Background

Exposure to green space seems to be beneficial for self-reported mental health. In this study we used an objective health indicator, namely antidepressant prescription rates. Current studies rely exclusively upon mean regression models assuming linear associations. It is, however, plausible that the presence of green space is non-linearly related with different quantiles of the outcome antidepressant prescription rates. These restrictions may contribute to inconsistent findings.

Objective

Our aim was: a) to assess antidepressant prescription rates in relation to green space, and b) to analyze how the relationship varies non-linearly across different quantiles of antidepressant prescription rates.

Methods

We used cross-sectional data for the year 2014 at a municipality level in the Netherlands. Ecological Bayesian geoadditive quantile regressions were fitted for the 15%, 50%, and 85% quantiles to estimate green space–prescription rate correlations, controlling for physical activity levels, socio-demographics, urbanicity, etc.

Results

The results suggested that green space was overall inversely and non-linearly associated with antidepressant prescription rates. More important, the associations differed across the quantiles, although the variation was modest. Significant non-linearities were apparent: The associations were slightly positive in the lower quantile and strongly negative in the upper one.

Conclusion

Our findings imply that an increased availability of green space within a municipality may contribute to a reduction in the number of antidepressant prescriptions dispensed. Green space is thus a central health and community asset, whilst a minimum level of 28% needs to be established for health gains. The highest effectiveness occurred at a municipality surface percentage higher than 79%. This inverse dose-dependent relation has important implications for setting future community-level health and planning policies.

中文翻译：

---

在荷兰，更多的绿色空间与更少的抗抑郁药处方率相关：一种贝叶斯地加分位数分位数回归方法

背景

暴露在绿色空间中似乎对自我报告的心理健康有益。在这项研究中，我们使用了客观的健康指标，即抗抑郁药处方率。当前的研究仅依赖于假设线性关联的均值回归模型。然而，有可能的是，绿色空间的存在与结果抗抑郁药处方率的不同分位数非线性相关。这些限制可能导致不一致的发现。

客观的

我们的目标是：a）评估与绿色空间相关的抗抑郁药处方率，以及b）分析抗抑郁药处方率的不同分位数之间的关系如何非线性变化。

方法

我们使用了荷兰市政当局2014年的横断面数据。对15％，50％和85％的分位数进行了生态贝叶斯地理可加性分位数回归，以估计绿地与处方率的相关性，控制体育活动水平，社会人口统计学，城市化程度等。

结果

结果表明，绿色空间总体上与抗抑郁药处方率成反比和非线性关系。更重要的是，尽管差异不大，但各分位数之间的关联性却有所不同。明显的非线性是明显的：在较低的分位数上，该关联是轻微的正相关，而在较高的分位数上，则是强烈的负相关。

结论

我们的发现表明，市政当局内绿色空间的增加可能有助于减少所分配的抗抑郁药处方的数量。因此，绿色空间是健康和社区的中心资产，而为了获得健康，则需要将最低水平定为28％。最高的效果发生在市政部门的地面百分比高于79％的情况下。这种与剂量成反比的关系对制定未来社区级的健康和计划政策具有重要的意义。