To what extent do supervised drug consumption services incorporate non-injection routes of administration? A systematic scoping review documenting existing facilities

BACKGROUND: Most of the existing research on supervised consumption services (SCS) is focused on injection drug use. Less is known about the applicability of SCS for people who consume drugs orally, intranasally, or through inhalation. This is problematic because people who use drugs through modes other than injection are also at risk of overdose death and other harm, and experience barriers accessing health and social services. We aimed to describe existing SCS models that accommodate these alternate routes of drug consumption, and synthesize available information on characteristics of program participants. METHODS: We conducted a systematic scoping review of 9 peer-reviewed and 13 grey literature databases on SCS that incorporate non-injection routes of consumption. We screened 22,882 titles, and excluded 22,843 (99.8%) articles. We ultimately included 39 (0.2%) full-text articles; 28 (72%) of these articles explicitly identified SCS that permit alternate routes of consumption and 21 (54%) discussed characteristics of participants who consume drugs through non-injection routes. Data on study characteristics, terms and definitions, and site and program participant characteristics were extracted and double-coded. Extracted data were analyzed using descriptive statistics and narrative synthesis. RESULTS: Included articles describe 48 SCS that permit non-injection routes of consumption, most of which were located in Germany. The majority of these SCS were legally sanctioned and had models of care that were largely comparable to supervised injection services. Notable differences included physical infrastructure such as ventilated rooms or outdoor areas to accommodate inhalation, and shorter time limits on non-injection drug consumption episodes. Program participants engaging in non-injection forms of consumption were typically men over the age of 30 and structurally vulnerable (e.g., experiencing homelessness or unstable housing). CONCLUSIONS: Extant academic and grey literature indicates that site characteristics and demographics of program participants of SCS that permit non-injection routes of consumption largely reflect those of supervised injection services. Further research on the range of existing SCS that incorporate non-injection routes of consumption is needed to ensure high quality service provision, and improved health outcomes for people who consume drugs via oral, intranasal, and inhalation routes.