*Outcome:*

	- Changes in substance use (uptake/initiation, harms associated with use, cessation, reduction)
	- Changes in client perceptions/attitudinal change
	- Changes in service provider perceptions
	- Changes in retention/treatment completion

Note: Studies that report on one or more of the four substances in relation to sex/gender *only* in the baseline characteristics of the sample will be excluded, even if statistical significance is reported.

#### **References**


© 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).

International Journal of *Environmental Research and Public Health*
