*2.1. Search Strategy*

In developing our search criteria we decided to exclude research on self-harm due to wide international variations in definitions based on degree of suicidal intent [13], although acknowledging that self-harm is a key risk factor for suicide in men in high-income countries [14]. We chose the age range 15–29 to cover WHO definitions of youth (aged 15–24 years), teenagers (aged 15–19 years), and young adults (aged 20–24 years) [1], as well as the upper limit of under 30 used in the Greenlandic suicide prevention strategy [9]. We registered our review protocol on PROSPERO register of systematic reviews, and used the PRISMA checklist to guide the design and reporting of our study [15].

We searched the online database, PubMed, using the MeSH terms "Suicide" and "Greenland" and the equivalent keywords Suicid\* and Greenland, to give the final search criteria (("Suicide" [Mesh]) OR Suicid\*) AND ("Greenland" [Mesh] OR Greenland). We used no date restrictions on publication period. The search was repeated on Embase, and with slight variation on PyscINFO as the MeSH term "Greenland" was not available. No restrictions were applied to age-range or gender, as the predicted relatively limited number of articles on this topic made it feasible to apply age and gender exclusions post-search. We conducted the search on 11 October 2017 and screened titles and abstracts for eligibility, followed by full text review. We conducted secondary searching of the reference lists of identified articles, and of the publications lists of identified authors, and emailed international experts in the field to identify additional references. We repeated the search in PubMed on 15 August 2018 to check for any recent studies.

### *2.2. Inclusion and Exclusion Criteria*

We included articles:


We excluded articles:

