Analysis and sorting by research question phraseology:

• Research question 1: Do you believe that physicians deserve the legal right to prescribe cannabis to patients? (i.e. Do you believe that cannabis should be legalized for therapeutic purposes?)

Qualified survey questions included the following phrases:

• “Doctors should be able to legally prescribe marijuana as medical therapy” (Charuvastra et al. 2005; Philpot et al. 2019).
• “Doctors should recommend medical marijuana (MMJ; as medical therapy)?” (Chan et al. 2017; Kondrad and Reid 2013).
• “Marijuana should be made available by prescription”) (Doblin and Kleiman 1991; Jacobs et al. 2018; Schwartz et al. 1997; Uritsky et al. 2011).
• “Cannabis should be legalized/available for medicinal purposes” (Bega et al. 2016; Crowley et al. 2017; Mathern et al. 2014; Norberg et al. 2012; Sideris et al. 2018).
• “Clinicians should be able to authorize MC without fear of legal action” (Carlini et al. 2016).
• “MMJ should be legalized in all states” (Moeller and Woods 2015).
• “Specialist physicians should have authority to prescribe CTP” (Balneaves et al. 2018; Ziemianski et al. 2015).
• “The use of CTP should be legalized/approved in Serbia” (Kusturica et al. 2019; Stojanovic et al. 2017).
• “MD’s should play a role in MMJ authorization” (Ebert et al. 2015).
• “MJ should be legalized provided it is under medical supervision” (Burke and Marx 1971).
• “There should be some form of legalized marijuana use" (Lieff et al. 1973).
• “Are you willing to help patients access MMJ?” (Ananth et al. 2018).

• Research question 2: Do you believe that cannabis has any therapeutic utility?

Qualified survey questions included the following phrases:

• “If marijuana were legally available, I would recommend the use of marijuana to a patient” (filed under the survey subscale “belief that marijuana has medical benefits”) (Chan et al. 2017).
• I am concerned that there is limited evidence demonstrating cannabis’ medical efficacy (Those who reported “low concern” were interpreted as espousing belief in MC’s utility) (Ricco et al. 2017).
• “Marijuana helps patients who suffer from chronic, debilitating medical conditions” (Carlini et al. 2016; Ebert et al. 2015; Kondrad and Reid 2013).
• “Do you believe that MMJ can help prevent nausea and vomiting (in patients receiving chemotherapy or radiation)?” (Braun et al. 2018; Doblin and Kleiman 1991; Luba et al. 2018).
• “Do you approve of using MMJ to help manage patients’ symptoms?” (Ananth et al. 2018).
• “Do you think MMJ has medical benefits/efficacy?” (Mitchell et al. 2016; Szyliowicz and Hilsenrath 2019; Uritsky et al. 2011).
• “Do you believe legalization [of cannabis] would be medically efficacious?” (Cogswell and Harris 2015).
• “Do you believe that MC is a legitimate medical therapy?” (Philpot et al. 2019).
• “Do you recognize MMJ as an oncological therapy?” (Moeller and Woods 2015).
• “Do you have a patient who you agree would benefit from medical cannabis?” (Karanges et al. 2018).
• “Are you certain about MMJ’s therapeutic value?” (Auger et al. 2020; Ziemianski et al. 2015).
• “Cannabis has a role in palliative care” (Crowley et al. 2017).
• “Assess your concern regarding the limited evidence of therapeutic benefits from MMJ” (1-7 Likert scale [1 = least concern, 7 = most concern]; responses of 1-3 were approved and consolidated for analyses reporting “confidence in cannabis’ medical efficacy”) (Hwang et al. 2016).
• “Do you believe [medical] marijuana/CBD has efficacy in treating (childhood) epilepsy?” (Ablin et al. 2016; Hwang et al. 2016; Mathern et al. 2014).
• “Do you believe that marijuana has an acceptable role in medicine?” (Martins-Welch et al. 2017).
• “I am familiar with the possible therapeutic effects of cannabis” (Kusturica et al. 2019).
• “Do you agree that cannabis and its derivatives could potentially have therapeutic effects?” (Stojanovic et al. 2017).

• Research question 3: Do you believe that marijuana should be legalized for recreational use?

Qualified survey questions included the following phrases:

• “(Do you believe that) marijuana should be legalized for recreational use?” (Berlekamp et al. 2019; Chan et al. 2017; Kondrad and Reid 2013; Moeller and Woods 2015; Schwartz et al. 1997).
• “What legal action should be taken for the possession of marijuana: 1) No legal action; 2) Citation with a fixed fine; 3) Misdemeanor; 4) Felony? (Linn et al. 1989).
• “Marijuana should be regulated in the same way as alcohol” (Lieff et al. 1973).
• “Should cannabis be made recreational?” (Bega et al. 2016).
• “Are you in favor of legalizing cannabis for non-medical purposes?” (Ebert et al. 2015).
• “Free access should be granted for the use of marijuana” (Burke and Marx 1971).
• “All marijuana should be legalized” (Uritsky et al. 2011).

• Research question 4: [For US-based papers only] Do you believe that the USA should amend cannabis’ federal status as a Schedule 1 controlled substance (the most restrictive classification, asserting that the substance has no accepted medical use)?

Qualified survey questions included the following phrases:

• “Do you favor the Drug Enforcement Agency (DEA) reclassifying marijuana so that it is no longer a Schedule 1 drug?” (Bega et al. 2016; Chan et al. 2017; Kondrad and Reid 2013).
• “Do you support the rescheduling of marijuana to permit its use in medicine?” (Doblin and Kleiman 1991; Schwartz et al. 1997).
• “Cannabis should be rescheduled so that it is no longer a Schedule 1 drug with no medical benefits” (Carlini et al. 2016).
• “Do you favor change in (federal) marijuana control?” (Burke and Marx 1971).

• Research question 5: Do you feel confident in your level of knowledge regarding the health effects of cannabis?

Qualified survey questions included the following phrases:

• “Do you feel confident in your ability to prescribe marijuana, or would you require more knowledge before prescribing?” (Doblin and Kleiman 1991).
• “Self-reported knowledge of cannabis” (reported on a 1-5 Likert scale; responses of 3, 4, or 5 [acceptable, strong, and very strong knowledge, respectively] were approved and consolidated for analyses reporting “confidence in knowledge of medicinal cannabis”) (Norberg et al. 2012).
• “Self-reported competency regarding knowledge of MMJ efficacy” (1-5 Likert scale; responses of 4 or 5 [strong and very strong knowledge, respectively] were approved and consolidated for analyses reporting “confidence in knowledge of medicinal cannabis”) (Ricco et al. 2017).
• “How much knowledge do you have about medical marijuana?” (6 categories: very little knowledge, some knowledge, moderate knowledge, substantial knowledge, high level of knowledge, and professional level of knowledge; “substantial knowledge,” “high level of knowledge,” and “professional level of knowledge” were approved and consolidated for analyses reporting “confidence in knowledge of medicinal cannabis”) (Szyliowicz and Hilsenrath 2019).
• “Do you feel adequately prepared to answer patients’ questions about MMJ?” (Philpot et al. 2019)
• “Do you consider yourself well-informed about the endocannabinoid system?” (Sideris et al. 2018).
• “Do you consider yourself knowledgeable about MMJ therapy?” (Mitchell et al. 2016; Rapp et al. 2015).
• “Confidence in discussing risks and benefits of medical cannabis” (4 categories: very confident; somewhat confident; somewhat not confident, not at all confident; “very confident” and “somewhat confident” responses were approved and consolidated for analyses reporting “confidence in knowledge of medicinal cannabis”) (Zylla et al. 2018).
• “I have good knowledge around the (side) effects of medicinal cannabis” (Karanges et al. 2018; Kusturica et al. 2019).
• “I know how to talk to providers about the risks and benefits of MMJ use” (“confident” and “somewhat confident” responses were approved and consolidated for analyses reporting “confidence in knowledge of medicinal cannabis”) (Caligiuri et al. 2018).
• “Do you feel sufficiently knowledgeable to make recommendations regarding MMJ?” (Braun et al. 2018).
• “Self-reported competency in MMJ pharmacology” (1-7 Likert scale; responses of 5-7 [good, very good, and excellent, respectively] were approved and consolidated for analyses reporting “confidence in knowledge of medicinal cannabis”) (Hwang et al. 2016).
• "Do you feel confident regarding your current knowledge of [cannabinoids]? (responses of “confident” and “somewhat confident” were approved and consolidated for analyses reporting “confidence in knowledge of medicinal cannabis”) (Ablin et al. 2016; Fitzcharles et al. 2014).
• “Knowledge of pharmacology and indications" (responses indicating a “medium-high” or “high” level of knowledge were approved and consolidated for analyses reporting “confidence in knowledge of medicinal cannabis”) (Ebert et al. 2015).
• “How would you rate your knowledge on the systemic effects of cannabis?” (Crosby 2018).
• “Rate your knowledge on factual information regarding marijuana" (responses indicating “moderate” and “high” levels of knowledge were approved and consolidated for analyses reporting “confidence in knowledge of medicinal cannabis”) (Burke and Marx 1971).

• Research question 6: Do you desire additional education regarding MMJ and/or do believe that education on (medical) cannabis should be made readily available to medical professionals?

Qualified survey questions included the following phrases:

• “(More) training about medical marijuana should be incorporated into medical/pharmacy school curriculum” (Bega et al. 2016; Caligiuri et al. 2018; Chan et al. 2017; Moeller and Woods 2015).
• “Continuing medical education (CME) about medical marijuana should be made available to (primary care) physicians” (Carlini et al. 2016; Ebert et al. 2015; Kondrad and Reid 2013).
• “People in my position should receive education about cannabis” (1-5 Likert; responses of “somewhat agree” and “fully agree” were approved and consolidated for analyses reporting “yes” for the stated research question) (Norberg et al. 2012).
• “Do you feel that more education about marijuana is needed?” (Szyliowicz and Hilsenrath 2019).
• “Are you interested in learning more about MC?” (Philpot et al. 2019; Zylla et al. 2018).
• “It would be helpful to have additional education about MMJ” (Rapp et al. 2015).
• “How strong is the need for education on CTP?” (responses reporting a “strong” or “very strong” need were approved and consolidated for analyses reporting “yes” for the stated research question) (Balneaves et al. 2018; Ziemianski et al. 2015).
• “Dispensing cannabis in the pharmacy requires additional education” (Stojanovic et al. 2017).

• Research question 7: Are you concerned about cannabis’ dependence/addiction potential?

Qualified survey questions included the following phrases:

• “(Do you believe that) marijuana can be addictive (yes/no)?” (Carlini et al. 2016; Chan et al. 2017; Kondrad and Reid 2013; Kusturica et al. 2019; Uritsky et al. 2011).
• I am concerned with MC’s potential for addiction or its psychoactive problems (those reporting “moderate” or “high” concern were approved and consolidated for analyses reporting concern) (Ricco et al. 2017).
• “Are you concerned about substance abuse among patients who receive MMJ?” (Ananth et al. 2018).
• “Are you concerned with MMJ’s potential for abuse/misuse/diversion?” (Rapp et al. 2015).
• “Do you believe / are you concerned that addiction and dependence are potential side effects of MC?” (Karanges et al. 2018; Martins-Welch et al. 2017; Stojanovic et al. 2017).
• “On the scale of 1-7 (1 = no concern, 7 = most concern), how concerned are you about the psychoactive effect and potential addiction from cannabis use?” (responses of 5-7 were approved and consolidated for analyses reporting “concern about MMJ’s addictive potential”) (Hwang et al. 2016).
• “The risk of addiction/physiological dependence would reduce my willingness to prescribe MMJ (1-5 Likert scale [1 = would not reduce my prescribing, 5 = would greatly reduce my prescribing]; responses of 4 and 5 were approved and consolidated for analyses reporting “concern about MMJ’s addictive potential”) (Jacobs et al. 2018).