Cannatechtoday reports..

Researchers at the University of Michigan Medical School recently conducted a survey involving 275 medical cannabis patients.

The survey involved medical cannabis patients in the United States, however, the results of the survey are similar to other results found throughout the globe and are applicable worldwide.

Survey participants were asked how confident they were when it comes to their primary care physician’s knowledge of medical cannabis.

“Only 18 percent of participants rated their PCP’s [primary care provider’s] knowledge about medical cannabis as very good or excellent and only 21 percent were very or completely confident in their PCP’s ability to integrate medical cannabis into their treatment,” researchers stated.

“Our study highlights the need for better integration between medical cannabis and mainstream healthcare, including enhancing PCP education on cannabis, the endocannabinoid system, and the benefits, risks, and harms of cannabis in relevant therapeutic contexts,” researchers concluded.

What is the Impact?

When patients do not have confidence in their primary physician, they are less likely to be candid about their lifestyle during interactions with their physician.

That can have a negative impact on the patient’s wellness strategy because their physician is giving guidance based on partial information.

The cannabis plant can interact with other medications in a way that may be undesirable or make a wellness strategy less effective than it otherwise would be.

Some patients will seek a second opinion, however, many will not and rely on a physician’s stigma-based guidance to refrain from using medical cannabis all together.

Here’s the Survey

Communication between healthcare providers and medical cannabis patients regarding referral and medication substitution



People report using cannabis as a substitute for prescription medications but may be doing so without the knowledge of their primary health care providers (PCPs). This lack of integration creates serious concerns, e.g., using cannabis to treat medical conditions that have established treatment options.


We conducted an anonymous, cross-sectional online survey among patrons of a medical cannabis dispensary in Michigan (n = 275) to examine aspects of their relationship with their PCP and their perceptions of PCP knowledge related to cannabis.


Overall, 64% of participants initiated medical cannabis use based on their own experiences vs. 24% citing advice from their PCP. Although 80% reported that their PCP knew they currently used medical cannabis, 41% reported that their PCP had not always known. Only 14% obtained their medical cannabis authorization from their PCP. Only 18% of participants rated their PCP’s knowledge about medical cannabis as very good or excellent and only 21% were very or completely confident in their PCP’s ability to integrate medical cannabis into their treatment. Although 86% had substituted cannabis for pharmaceutical medications, 69% (n = 134) of those who substituted reported some gap in their PCP’s knowledge of their substitution, and 44% (n = 86) reported that their PCP was currently unaware of their substitution.


Patients frequently substitute cannabis for prescription drugs, often without PCP knowledge. Although most participants disclosed cannabis use to their PCP, their perceptions of PCP knowledge ranged widely and many obtained medical cannabis licensure from an outside physician. Our results highlight the need for standardized physician education around appropriate medical cannabis use.


Thirty-five states in the USA have enacted medical cannabis programs. Despite being designated a Schedule I drug under the 1970 Controlled Substances Act in the US (indicating a high potential for abuse and no accepted therapeutic use), a recent National Academies of Sciences, Engineering, and Medicine report found evidence supporting the therapeutic value of cannabinoids (active compounds in cannabis) for chemotherapy induced nausea and vomiting, chronic pain, and multiple sclerosis-related spasticity (National Academies of Sciences, Engineering, and Medicine 2017). However, the evidence for most conditions allowed by state medical laws (e.g., depression) was insufficient (National Academies of Sciences E, and Medicine 2017; Boehnke et al. 2019a). Complicating this mismatch are scientific and news reports of individuals substituting cannabis for opioids and other prescription medications (Boehnke et al. 2016; Boehnke et al. 2019b; Lucas et al. 2016; Lucas and Walsh 2017; Lucas et al. 2019; Reiman et al. 2017; Piper et al. 2017; Corroon Jr. et al. 2017; Rod 2019)—including for conditions for which there is limited evidence that cannabis has therapeutic value (e.g., anxiety). Similarly, many individuals using cannabis believe that cannabis is useful for medical conditions with no evidence base (e.g., cancer treatment) (Kruger et al. 2020). Taken together, these findings highlight the need for a strong healthcare provider presence in conversations about safe cannabis use in the context of medication substitution.

Whether this substitution occurs with oversight from healthcare providers remains unknown, but healthcare providers consistently express a lack of knowledge about medical cannabis, demonstrated by studies showing that only 9% of medical schools cover medical cannabis (Evanoff et al. 2017) and ~ 80% of physicians reported needing additional cannabis education (Kondrad and Reid 2013). Further, when physicians are approached for medical cannabis recommendations, there are no formal guidelines for appropriate medical use. Among patients, those using cannabis may not approach healthcare providers for fear of stigma or legal trouble. Indeed, some institutional policies prevent physicians from recommending medical cannabis (Carlini et al. 2017), and patients may lose employment due to a positive drug screen even if they have a medical cannabis license (Kulig 2017). As such, many people may use cannabis without the knowledge of or input from their primary healthcare providers (PCPs) (Kruger et al. 2020), emphasizing the lack of integration of medical cannabis into mainstream healthcare settings.

In the current study, we further explored this lack of integration by surveying individuals using medical cannabis in Michigan, where cannabis is legal for medical and adult use (since 2009 and 2018, respectively). We hypothesized that although many participants would report substituting cannabis for medications, most would do so without PCP guidance. We also hypothesized that participants would report low PCP comfort and knowledge regarding medical cannabis.


Setting and participants

We invited patrons of Om of Medicine—a medical cannabis dispensary in Ann Arbor, Michigan—to complete an anonymous, online survey (administered via Qualtrics) through flyers, emails, and social media between April 2019 and February 2020. Emails with the survey link as well as other information (e.g., product specials) were sent out each month to the client database (~ 5000 people) approximately once per month, and flyers were located around the facility. Social media notices were made publicly without additional advertising. Dispensary staff informed patrons about the research study but otherwise had no involvement with their participation, and no special privileges or attention were given to individuals who chose to participate in the research. In Michigan, patient registry licenses are valid for two years and individuals can obtain licensure both from their PCP or from an outside provider who must be an MD or DO licensed in Michigan (Marijuana Regulatory Agency LaRA 2020).

Participants were > 18 years old and currently used cannabis for medical purposes. Participants answered questions on demographic information (sex, ethnicity, age, education), medical cannabis use and related substitution behaviors, and healthcare provider knowledge and attitudes toward medical cannabis. All procedures and surveys were approved as an exempt study by the Institutional Review Board at the University of Michigan under protocol HUM00165859. Participants freely consented to participate and were not compensated. Most respondents completed the survey (n = 275), 30 cases with incomplete data were not included.


Measures were adapted from several other studies of medical cannabis use and cannabis substitution (Boehnke et al. 2019b; Lucas and Walsh 2017; Kruger et al. 2020; Kruger and Kruger 2019).

Reasons for cannabis use

Participants selected their primary condition for using medical cannabis from an extensive list of options which we have used in other surveys (Kruger et al. 2020; Kruger and Kruger 2019). Participants indicated why they used medical cannabis from the following list of reasons: my own experiencesadvice from my primary health/medical care provideradvice from my medical marijuana caregiver/dispensaryadvice from other individual(s); and other source of information (Kruger et al. 2020; Kruger and Kruger 2019).

Patient disclosure of medical cannabis use to PCP

Participants were asked: “Does your primary care provider (PCP) know that you use medical marijuana?” and “Are you seeing (or did you see) your PCP for the health issue that you use medical marijuana to help treat?” Participants whose PCPs knew about their use were asked: “How did your PCP find out that you use medical marijuana?” and “Was there a time when your PCP did not know that you used medical marijuana?” Participants whose PCPs did not know about their use were asked: “Did your PCP ever ask you about medical marijuana?” and “Is there a reason why you did not tell your PCP about your medical marijuana use?”, with an open-ended text box to explain. Reported reasons were categorized by reoccurring themes.

Medical cannabis license authorization

Participants were asked whether their PCP authorized their cannabis license, the number of doctors visited to obtain their license, and whether their PCP was in contact with the physician who authorized their license. Those whose PCP did not authorize their license were asked how they found their authorizing physician, with response options: referred by my PCP; referred by a friend or family member; in a newspaper (Metrotimes, etc.); Internet search; and other: with an open-ended text box. These participants were also asked whether the doctor authorizing the license is still involved in their health care, and if they ever saw the authorizing physician again.

Perceptions of PCP knowledge and support for medical cannabis

Participants rated their PCP’s knowledge of medical cannabis as poorfairgoodvery good, and excellent; confidence in their PCP’s ability to integrate medical cannabis into their treatment as not at all confidentsomewhat confidentmoderately confidentvery confident, and completely confident; and perceptions of their PCP’s support of medical cannabis: not at all supportivesomewhat supportivemoderately supportivevery supportive, and completely supportive. All 5-point Likert-type scales were converted to continuous values (1–5) for statistical analyses.

Substitution measures

Participants were asked, “Have you ever or are you currently using or taking…” with response options for a wide range of drug classes used in other studies (Kruger and Kruger 2019). Participants who indicated using a drug class were asked, “Have you reduced your use of or stopped using [drug] because of medical marijuana?” (Boehnke et al. 2019b). Those who responded affirmatively selected the reasons why from the following: my own experiences; advice from my primary health/medical care provider; advice from my medical marijuana caregiver/dispensary; advice from other individual(s); and other source of information. These participants were also asked “Did your PCP know that you reduced or stopped your use of [drug] because of medical marijuana?” with response options of “Yes, immediately”, “Yes, but not immediately”, and “No”.

Statistical analyses

Descriptive analyses included frequencies and mean scores, with selections of subgroups as appropriate. Independent samples t-tests compared perceptions of PCP knowledge about medical cannabis, confidence in PCP’s ability to integrate medical cannabis into their treatment, and perceived PCP level of support of medical cannabis by whether or not their PCP knew that they used medical cannabis; whether their PCP had delayed knowledge of their medical cannabis use; whether their PCP knew that they substituted medical cannabis for pharmaceutical drugs; whether their PCP had delayed knowledge of their substitution, and whether their PCP had authorized their medical cannabis card. Chi-square analyses tested whether the distribution of participants whose PCP had authorized their medical cannabis license (compared to those who had not) was different with regards to gaps in knowledge of substitution and whether participants substituted cannabis for pharmaceutical drugs. All analyses were conducted in SPSS (IBM, Armonk, NY).