Page - 189 - in Biodiversity and Health in the Face of Climate Change

189 Due to the heterogeneity of the selected articles in terms of research design, measures and participants, data were analysed using narrative synthesis (Popay et  al. 2006). The purpose of narrative synthesis is to identify the factors that explain the differences in results in the body of literature (Popay et  al. 2006). Patterns of results across all 24 studies were identified according to study design, measures of biodiversity and mental health or well-being. Vote counting (Popay et  al. 2006) was used to describe the frequency of significant and non-significant results across the 24 quantitative studies. This analytical approach has been used previously (Lovell et  al. 2014). While we acknowledge that vote counting has known deficiencies (e.g. giving equal weight to studies with different research designs,  samples and effect sizes), it is a useful as a preliminary interpretation of results across studies (Popay et  al. 2006). Our findings should thus be interpreted with caution. 9.3 Results 9.3.1 Characteristics of  the  Recent Literature, Published Since  Lovell et  al.’s (2014) Review, Relating Biodiversity to  Mental Health and  Well-being The following describes the recent literature (n  =  16), published since 2012, on biodiversity and mental health and well-being. See Lovell et  al. (2014) for descrip- tion of the body of evidence up to 2012. All 16 studies examined, wholly or in part, the relationships between biodiver- sity and one or more mental health or well-being outcomes (see Table  9.1). Eleven studies were based in Western Europe, three in North America and two in Asia. Two studies were from emerging economies of Malaysia and Mexico. Six different study designs were used to examine the relationship between biodiversity and mental health and well-being (Fig.  9.2). 9.3.1.1 Spatial Scale The spatial scale at which the relationships were examined ranged from the national (Duarte-Tagles et  al. 2015; Wheeler et  al. 2015) to the local (Carrus et  al. 2015; Foo 2016; Marselle et  al. 2015, 2016). Specifically, scales considered whole countries (England (Wheeler et  al. 2015) and Mexico (Duarte-Tagles et  al. 2015)), geographi- cal regions within countries (England (Cox et  al. 2017), Finland (Rantakokko et  al. 2018), Sweden (Annerstedt van den Bosch et  al. 2015), the USA (Jones 2017)) and specific places such as forests in the Klang Valley region of Malaysia (Foo 2016), protected nature reserves in Singapore (Saw et  al. 2015) and green spaces in Italy (Carrus et  al. 2015). 9 Review of  the  Mental Health and  Well-being Benefits of  Biodiversity