Table 3 Summary of methods, types of evidence, facilitators and barriers

Ablin et al. 2016 [27]

The authors analyzed the medicinal cannabis regulatory frameworks in Canada and Israel. The analysis also included evaluations of the utilization, barriers, and unmet needs that exist in these countries. Finally, the authors examined the process of implementing these regulations in Germany.

The authors analysed the MMLs from Israel and Canada.

MC programs should collaborate with the medical community regarding the use of MC. Further; the medical community should be involved in the implementation and decision-making process. MC regulatory frameworks should be clear and address inconsistencies in MC policies.

Federal laws that act as a resistance to providing funding and creating opportunities for research on MC.

Bradford et al. 2017 [3]

The authors created an empirical model of policy adoption to determine factors that helped policy diffusion. This was done using an Event History Analysis. For the model, data on the status of states MMLs were obtained from several sources. Finally, the model allowed the authors to examine the policy demand and the role of policy diffusion forces and median voters on a state adopting a particular policy.

The data for this study was extracted from various sources including the Bureau of Labor Statistics, the Marijuana Policy Project, the Centers for Disease Control and Prevention, and the Office of National Drug Control Policy's Marijuana Resource Center. Moreover, the study also examined the National Conference of State Legislature, the United States Census Bureau, and the National Institute of Education Services.

States with neighbouring states that have implemented MMLs, states with liberal-minded citizens, and states that have a higher median household income are all more likely to implement MMLs.

The likelihood to adopt new regulations decreases as motivational effects decrease between those who wish to adopt and those who do not.

Campbell et al. 2015 [26]

The authors analyzed Americans for Safe Access, Craker's Petition, the Controlled Substances Act, and the role of research in the context of the MMLs.

The authors reviewed and analyzed the following data: American's for Safe Access, Craker's Petition, and the Controlled Substances Act.

Changing the Controlled Substance Act (CSA) so that the federal MC regulations are consistent with the classification of the drug with state-level regulations.

The inconsistency between the federal classification of MC as a Schedule 1 drug and state laws prevents opportunities for clinical and empirical research on MC.

Choo et al. 2017 [18]

The authors performed a literature review of MMLs in the US.

The study was a literature review of MMLs and policy analyses.

None discussed.

The complexities and inconsistencies of MMLs, as well as the inherent characteristics of laws to undergo constant and rapid change makes them difficult to study.

Cohen et al. 2010 [28]

The authors performed a literature review of MC policies in the US.

Authors examined the various MC regulations in the US.

Physicians must act as gatekeepers of MC and should supervise the recommendation and distribution of MC. Further, physicians must be supervised by the board of medicine.

None discussed.

Davenport et al. 2016 [30]

Authors reviewed the implementation process, the Dangerous Drug Act (DDA) amendment. This was followed by a comparison of the statutory changes under DDA to other jurisdictions. Finally, other publicly available information and unstructured interviews with non-government stakeholders in Jamaica were also examined.

The authors drew on publicly available information and unstructured interviews with non-governmental stakeholders in Jamaica. Additionally, they cited publicly available government sources including secondary school and Jamaican household surveys. Information was also gathered from media reports including press releases and government statements.

The regulatory framework should also be revised to ensure that the demand for MC license reflects the number of applications, outlines the process and length of getting a license, highlights the demand for MC in the region, and the influence of MC regulations on tourism. The regulatory framework should also consider the influence of cultivators and retailers.

There must be clear guidelines for patients on which health conditions MC can be prescribed for, which health care practitioners are available for recommending MC, and what MC product is available for use.

Flexon et al. 2019 [19]

Authors conducted a multivariate regression analysis of data obtained from the National Survey on Drug Use and Health from 2015-2017 to determine whether medical marijuana laws had any effect on opioid use and misuse. A supplemental longitudinal panel analysis using data from the Interactive National Survey on Drug Use and Health State Estimates from 2002 to 2017 was also conducted.

The authors examined states that permit the medicinal use of cannabis.

In states that implemented MMLs, opioid reliance was effectively reduced.

None discussed.

Grbic et al. 2017 [20]

The study divided participants into two groups: group one consisted of government officials, lobbyists, medical professionals and group two consisted of researchers. Each group answered a questionnaire. Lastly, a third group consisting of members of the International Society for the Study of Drug Policy were interviewed. Data from each group were evaluated using thematic analysis.

The authors conducted a thematic analysis of the data extracted from the questionnaires and interviews with government officials, lobbyists, and medical professionals.

Authors found there to be a need for improved communication between researchers and policymakers to make evidence more accessible to the latter.

The lack of evidence within a political context and the lack of research on the actual implementation process of MC policies can act as a barrier.

Hammer et al. 2015 [21]

The study used data collected from medical marijuana websites, phone conversations, and public election and census results to develop a framework testing political culture as a proxy for social construction and the relationship between public attitudes and the implementation of medical marijuana laws.

The authors used data collected from medical marijuana program websites and phone conversation and survey results, as well as, data from 2010 Census Estimates and 2008 county election returns. Data obtained was regarding the MC program structure and implementation factors.

The implementation of MC regulations must take into consideration the role of local cultural factors during decision-making. The target population for the MC regulations must be seen as socially constructed groups. Finally, the MC implementation process includes patients advocates, the public health community, and law enforcement.

None discussed.

Heddleston et al. 2013 [15]

The study used data extracted from interviews, archival research, meeting observations, and official city documents to explore the varying experiences of San Francisco, Los Angeles, and San Diego regarding official responses to medical marijuana providers. The author also used such information to determine how the ways that activists open political opportunity structures contribute to regulatory approaches to medical marijuana.

Data for the case studies were collected from interviews with individuals who played a vital role in the MC regulation implementation process. The data also included information from archival data, literature reviews, and observational notes from the city council Cannabis Task Force meetings.

MC regulations are facilitated by ensuring law enforcement understands and sympathizes with the movement, establishing regulatory committees that can ensure the regulation of MC, creating local ballot initiatives, and having a city council that is pro-MC. According to the San Francisco Bay case study, the use of rallies and participation in city task forces further facilitated MC regulation. The model also showed that lobbying could aid with the facilitation.

According to the Los Angeles model, the absence of local ballot initiatives and inconsistent city council regulations, dispensaries became commercialized. As a result, social movements were not able to lobby for revised MC regulations. The San Diego model highlighted that the lack of local ballot initiatives, absence of MC regulations, and unsympathetic local law enforcement and city officials made it difficult to establish an MC regulatory framework.

Kim et al. 2018 [13]

Authors conducted a policy analysis through a mixed methods approach through qualitative data extracted from news reports searched by Los Angeles Times Archives, Chicago Tribune Archives, Denver Post News Archives, NewsBank and Google News Archive Search and quantitative information obtained from state level annual data.

The authors used the extracted data to undergo a thematic analysis and examine the three policy models: morality, economic, and multidimensional policy models.

States that utilized a ballot initiative tool, including California, Alaska, Oregon, Washington, Maine, and Colorado, found it to facilitate the MC law implementation process. Moreover, states that aim to stimulate economic goals will implement an MC law while states that have the support of cannabis users also increases chances of implementation. It was noted that according to the morality model, states with higher uses of cannabis and liberal-minded citizens have a higher likelihood of adopting an MC law. According to the economic policy model, states that have faced low fiscal capacity growth, have high incarceration rates, or have high costs associated with their justice system, will be more likely to implement a MC law. Similarly, states without a mandatory minimum sentencing law and smaller regulatory bureaucracy also show an increased likelihood to implement an MC law.

None discussed.

Lamonica et al. 2016 [9]

The authors used data extracted from analysis of ethnographic fieldwork that included observation notes from public meetings and in-depth interviews with stakeholders. Finally, data was also collected from interviews with stakeholders who followed policy development closely.

The authors used data from the MC policy implemented and regulated by the Massachusetts Department of Public Health.

The implementation of MC regulations can be facilitated through understanding the needs of stakeholders. Policymakers must ensure transparency and clear communication during the process; communication through ballot initiatives is an effective way of relaying information between politicians/policymakers and stakeholders and patients. The regulation must also consider and include MC education to ensure that it is not misunderstood by those interpreting it.

The lack of transparency and ineffective communication and education regarding MC regulations can lead to a misunderstanding of the information provided within them.

Lucas et al. 2008 [1]

The authors conducted a policy analysis using an evidence-based review of three facets of Health Canada's medicinal cannabis policy and the federal cannabis production and distribution program, in addition to examining Canada's network of unregulated community-based dispensaries.

Data for the study was collected from Canada's court decisions, government records, relevant studies, and network of unregulated community-based dispensaries. Moreover, the authors reviewed the Access to Information Act and the following policies: the Marihuana Medical Access Division (MMAD), the Canadians Institute of Health Research Medical Marijuana Research Program, and the federal cannabis production and distribution program.

The government must work with community-based medical cannabis compassion clubs, address safe and effective access to MC, and increase clinical research to address patient concerns.

None discussed.

Lucas et al. 2012 [22]

Authors used patient surveys and semi-guided interviews to assess the patient experience associated with Health Canada's MMAD. The data was then analyzed to determine the experiences and associated challenges with the program.

Data on Health Canada's MMAD and the quality of the service provided by the program was collected from a fifty question online survey along with twenty participants given semi-guided interviews.

The challenges faced by Health Canada's MC program can be ameliorated by increasing patient engagement and involvement, redirecting the responsibilities of MC towards healthcare professionals creating a community-based model by collaborating with local dispensaries, and increasing research on MC and its effects.

Challenges to patient access to MC include the absent role of the healthcare/medical community as a gatekeeper to MC, the burdensome application process and legal threats and issues caused by the federal government regarding MC.

Miyaji et al. 2016 [23]

The authors conducted a literature review of the archived official documents after World War II (1945–1948). This was followed by an analysis of the events that led to the implementation of MC regulations.

Authors extracted data from nationally archived official documents associated with the Cannabis Control Act (CCA). The documents were first developed at the end of World War II (1945 to 1948).

The development of an MC regulatory framework can be facilitated by reforming Article 4 of Cannabis Control Act (CCA). Regulations should ensure research opportunities to reduce any resistance in drug development, and create compassionate use programs.

None discussed.

Pacula et al. 2002 [31]

The authors conducted original legal research on the current state MC laws. The analysis was followed by an analysis of the fifty states and their MC regulations by comparing them with other dimensions.

Authors collected evidence from the Controlled Substance Act and Marijuana Policy Project.

None discussed.

States must ensure that a MC law that regulated MC supply must not increase recreational cannabis. Regulatory bodies must also take into consideration the medical necessity defense in state courts when implementing MC laws.

Pacula et al. 2014 [14]

The authors used public versions of the laws and examined the information in the laws using a systematic content analysis approach. The focus of the analysis was on determining when different factors of the laws were established, followed by an analysis of how the laws impacted access.

The authors analyzed all MMLs of 50 states enacted from 1990 to 2012.

In order to create regulations that are effective and efficient and to understand the outcomes of such mechanisms, there must be more empirical research on how patients respond to MMLs.

Policymakers find it challenging to establish an MC regulation program due to the illegal status of MC at the federal level that prevents MC from being treated as a medical product and regulated by the Federal Drug Administration. The inconsistencies in MMLs between states pose challenges for public health.

Pardo et al. 2014 [24]

Authors collected data from recent laws and regulations, discussions with the regulators in Uruguay, and the US states of Colorado and Washington. The data was then analyzed and compared in terms of cannabis prices, taxation, and supply and production.

The authors examined laws, regulations, and discussions with regulators and functionaries of each jurisdiction.

MC regulatory frameworks must reflect MC reforms and their influence on price and tax structures on MC regulation.

MC regulatory frameworks are challenged by the lack of evidence on the impact MC reforms may have. The taxation of cannabis can impact sales by making the product expensive for consumers. In Uruguay, it was found that a low market price for cannabis hindered revenue generation and may not influence the removal of illegal cannabis markets.

Smith et al. 2013 [17]

The authors used a case study method to analyze the Medical Marijuana Act (MMA) and its legitimacy through face-to-face and phone call interviews with the participants discussed previously.

The authors used face-to-face interviews with experts in the medical marijuana law field and attorneys and advocates involved in MC issues, as well as an analysis of court cases regarding the MMA.

It is important to ensure safe access to MC and protect the rights and privacy of patients and caregivers.

Due to the inconsistency and contradictions between the Schedule 1 classification of cannabis at the federal level and the MC laws in Michigan, the legitimacy and administration of MC at the state level is challenged. It is difficult to interpret and regulate MC laws because of this ambiguity.

Taylor et al. 2016 [25]

The authors collected previously unknown archival data to analyze changing attitudes towards the control of cannabis, the relationship between science and policy, and the impact of the policy environment on the process of re-medicalization.

The authors collected archival data from the Advisory Council on the Misuse of Drugs held at the National Archives from 1972–1982.

Re-medicalization of cannabis can be accomplished by increasing the amount of research conducted on MC, ensuring a relaxed stance towards the drug, and removing MC from drug control.

None discussed.

Tilburg et al. 2019 [16]

The authors analyzed the impact of federal restrictions on various aspects of regulation development in the cannabis industry.

Authors analyzed and collected evidence from state vs. federal MML policies.

None discussed.

Due to the conflict between the categorization of MC as a Schedule 1 drug in the USA and the legalization of cannabis at the state-level makes regulating MC difficult. Moreover, due to the lack of federal involvement in the cannabis industry, the development of a regulatory framework for MC research is negatively impacted.

Zarhin et al. 2018 [29]

Authors used interviews with stakeholders in the MC policy field, policy documents, and conference observations to highlight the dynamics between rhetorical and regulatory boundary-work. Data was also extracted from government resolutions on MC, information from Form 106, and data from an information booklet titled “Cannabis for medicinal use: An information booklet and medical guidelines”.

The authors drew information from the interviews with key stakeholders in the MC policy field, formal policy documents including Form 106, and observations of MC conferences.

Authors found that having an MC license system authorized by the state, the use of expert knowledge or the use of physicians as gatekeepers acts as a facilitator legitimizing MC.

None discussed.