Background: A growing body of research assesses population need for substance use services. However, the extent to which survey research incorporates expert versus consumer perspectives on service need is unknown. We conducted a large, international review to (1) describe extant research on population need for substance use services, and the extent to which it incorporates expert and consumer perspectives on service need, (2) critically assess methodological and measurement approaches used to study consumer-defined need, and (3) examine the potential for existing research that prioritizes consumer perspectives to inform substance use service system planning.Methods: Systematic searches of seven databases identified 1930 peer-reviewed articles addressing population need for substance use services between January 1980 and May 2015. Empirical studies (n = 1887) were categorized according to source(s) of data used to derive population estimates of service need (administrative records, biological samples, qualitative data, and/or quantitative surveys). Quantitative survey studies (n = 1594) were categorized as to whether service need was assessed from an expert and/or consumer perspective; studies employing consumer-defined need measures (n = 217) received further in-depth quantitative coding to describe study designs and measurement strategies.Results: Almost all survey studies (96%; n = 1534) used diagnostically-oriented measures derived from an expert perspective to assess service need. Of the small number (14%, n = 217) of survey studies that assessed consumer's perspectives, most (77%) measured perceived need for generic services (i.e. 'treatment'), with fewer (42%) examining self-assessed barriers to service use, or informal help-seeking from family and friends (10%). Unstandardized measures were commonly used, and very little research was longitudinal or tested hypotheses. Only one study used a consumer-defined need measure to estimate required service system capacity.Conclusions: Rhetorical calls for including consumer perspectives in substance use service system planning are belied by the empirical literature, which is dominated by expert-driven approaches to measuring population need. Studies addressing consumer-defined need for substance use services are conceptually underdeveloped, and exhibit methodological and measurement weaknesses. Further scholarship is needed to integrate multidisciplinary perspectives in this literature, and fully realize the promise of incorporating consumer perspectives into substance use service system planning.

BACKGROUND:Access to harm reduction interventions among substance users across Canada is highly variable, and largely within the policy jurisdiction of the provinces and territories. This study systematically described variation in policy frameworks guiding harm reduction services among Canadian provinces and territories as part of the first national multimethod case study of harm reduction policy. METHODS:Systematic and purposive searches identified publicly-accessible policy texts guiding planning and organization of one or more of seven targeted harm reduction services: needle distribution, naloxone, supervised injection/consumption, low-threshold opioid substitution (or maintenance) treatment, buprenorphine/naloxone (suboxone), drug checking, and safer inhalation kits. A corpus of 101 documents written or commissioned by provincial/territorial governments or their regional health authorities from 2000 to 2015 were identified and verified for relevance by a National Reference Committee. Texts were content analyzed using an a priori governance framework assessing managerial roles and functions, structures, interventions endorsed, client characteristics, and environmental variables. RESULTS:Nationally, few (12%) of the documents were written to expressly guide harm reduction services or resources as their primary named purpose; most documents included harm reduction as a component of broader addiction and/or mental health strategies (43%) or blood-borne pathogen strategies (43%). Most documents (72%) identified roles and responsibilities of health service providers, but fewer declared how services would be funded (56%), specified a policy timeline (38%), referenced supporting legislation (26%), or received endorsement from elected members of government (16%). Nonspecific references to 'harm reduction' appeared an average of 12.8 times per document-far more frequently than references to specific harm reduction interventions (needle distribution=4.6 times/document; supervised injection service=1.4 times/document). Low-threshold opioid substitution, safer inhalation kits, drug checking, and buprenorphine/naloxone were virtually unmentioned. Two cases (Quebec and BC) produced about half of all policy documents, while 6 cases - covering parts of Atlantic and Northern Canada - each produced three or fewer. CONCLUSION:Canada exhibited wide regional variation in policies guiding the planning and organization of Canadian harm reduction services, with some areas of the country producing few or no policies. Despite a wealth of effectiveness and health economic research demonstrating the value of specific harm reduction interventions, policies guiding Canada from 2000 to 2015 did not stake out harm reduction interventions as a distinct, legitimate health service domain.