Inclusion and Exclusion Criteria

Suicidality and self-harm were operationalized as any incidence of self-harm and/or suicidality, including completed or attempted suicide rates and suicide ideation.

To be eligible for inclusion, studies had to (1) present empirical data, (2) be available in English, (3) include a measure of suicide (either actual rates or ideation) and/or self-harm, (4) include a measurement and/or condition explicitly related to an aspect of urban living, (5) report data from the UK and Ireland, and (6) be published in a peer-reviewed journal. We classified aspects of urban living as features of the built environment (e.g. buildings, transport), and the environmental elements of urban living (e.g. access to green space, noise, pollution). Social aspects of the urban environment, namely socioeconomic status, social fragmentation, and characteristics of local communities, were also considered important features of the urban environment.

The following were excluded: (1) protocol, theoretical, or position papers; (2) studies focusing on assisted suicide; (3) studies measuring suicide or self-harm stigma only; (4) studies focussing on rural living only (without an urban comparison); (5) those focussing on murder/homicide preceding suicide; (6) those focussing on substance abuse or overdose (where intent cannot be established); (7) those including a measurement/condition related to geography and/or living but this is not explicitly tied to urbanicity; (8) reports data from the UK that could not be separated from multi-national data; or (9) reports suicide/self-harm rates in the context of persons with a specific condition (e.g. people with a particular physical or psychological difficulty). Studies were not excluded based on the methodology used.