Seven electronic databases were selected for their ability to capture relevant literature across disciplines of interest (e.g. medicine, psychology, nursing and social science), including MEDLINE, EMBASE, PsycINFO, CINAHL, Web of Science, EBM Reviews and Cochrane Database of Systematic Reviews. A comprehensive review of these databases was conducted between November and December 2010 to identify English-language published studies, dissertations and conference proceedings. No restrictions were placed on publication year or methodological design. Combinations of keywords related to ‘stigma’ and ‘substance use disorder’ were entered into the above databases, and the ‘titles’ and ‘abstract’ fields were searched (Table S1; details of supporting information are given at the end). Additional publications were identified by scanning reference lists of articles and consulting with experts and key informants. We also hand-searched the content pages of nine journals that had published studies on the topic of substance use-related stigma (Table S2; details of supporting information are given at the end). Grey literature searches were also conducted by entering keywords into search engines, databases and content-relevant websites selected in consultation with experts in the field (Table S3; details of supporting information are given at the end).
