Sunday, April 14, 2019

A High Level Review of Medical Marijuana

by Bob Arnold (@rabob)

This article isn’t going to change your practice. Why am I reviewing Braun et al.’s survey regarding oncologists’ beliefs, practices, and knowledge regarding medical marijuana use? 1. I went to a Willie Nelson concert and my clothes still reek of marijuana; 2. One of my palliative care fellows is interested in understanding Palliative Care clinicians’ educational needs regarding marijuana; 3. I visited a dispensary in Pennsylvania where I was told medical marijuana treats diseases ranging from opioid addiction to headaches to nausea and vomiting (in pregnant woman). This annoyed me and I wanted to see what other doctors thought.

First, a caveat, I have provided medical care for HIV positive patients for over 25 years and I view recreational marijuana use like recreational alcohol use, something that is a personal choice and of minimal risk. I am not sure of marijuana’s medicinal effects (I believe the data is very poor) and I think in moderation it is safe.

When Pennsylvania legalized medical marijuana, I signed up and of the roughly 25% of the patients I see in my oncology palliative care practice are referred by oncologists for medical marijuana. Everyone asks me about medical marijuana – from the administrative assistants to my colleagues and oncologists. I therefore was quite interested to learn what Braun et al. had discovered regarding oncologists’ beliefs, practices, and knowledge about therapeutic marijuana use. (1) They surveyed a nationally representative sample of oncologists including medical, gynecological, neurological, and pediatric who were involved in patient care. Radiation oncologists were excluded. They were interested in whether oncologists reported discussing medical marijuana with patients, recommended it, or felt sufficiently informed to make such recommendations. The survey also queried oncologists’ views on medical marinjuana’s comparative effectiveness for several conditions. Bivariate and multivariate analyses were performed using standard statistical techniques.

They surveyed 400 medical oncologists and had a response rate of 63%. The oncologists were predominantly white males and were equally split between being in practice less than 15 years, 15-24 years, and greater than 25 years. Interesting they didn’t tell me how many of them used marijuana recreationally or what their views were about recreational marijuana. Roughly 50% practiced in states where medical marijuana was legalized.

Despite only 50% practicing in a state where medical marijuana was legalized, 80% had discussed it with patients and 46% had recommended it to at least one patient in the last year. Only 25% felt sufficiently knowledgeable to make recommendations and 56% of those who had recommended it did not consider themselves to have sufficient knowledge to make a recommendation.

Given their lack of knowledge their views regarding medical marijuana’s effectiveness for various symptoms should be taken with a grain of salt. Regarding pain they were split a third yes, a third no, a third don’t know; regarding anorexia 60% thought it was equally or more effective than standard therapies; 45% thought it equally or more effective for anxiety. Oncologists viewed medical marijuana as lower risk than opiates for death and addiction, and comparable to opiates for paranoia and confusion.

As a study, this survey is rigorously conducted. They based the survey on semi-structured interviews with key informants and did cognitive interviews prior to finalizing the instrument. They had a highly trained group administer the survey. Their response rate was great for physicians and their sample was nationally representative. Their aims were clear, and their survey questions and analysis allowed them to answer aims.

My concerns have to do with the study implications ( here comes the personal opinion). First, should doctors make recommendations for a therapy that they report not competent to talk about? If we had good data on the effects of medical marijuana and this was just a problem of education, then the solution would be to train doctors. However, the problem is that there is NO DATA and our federal government has been unwilling to fund studies of effectiveness. (2,3) We are flying blind and not trying to shed light on the topic. Second, at least in Pennsylvania, we have a very weird system where my opinion as a doctor does not really matter. From a legal point of view, all I do is certify that the patients have a condition that the legislature approves them to receive a medical marijuana card. They then go to a dispensary where others advise the patient on dose and type of marijuana. The scientific basis of these recommendations – given the lack of data – is unclear. And dispensaries – despite prescribing medical marijuana - are not part of the healthcare system. Their records are not integrated into the health care system, they do not know the patient’s other medications, and there is little communication with certifying clinicians. Third, given the rates of medical marijuana use in states like California (4% of the population in one study; 916,000 in another report) and the overlap between medical and recreational use (3,4), one wonders if the doctors aren’t too loosely interpreting the criteria. (5)

Rather than medicalizing marijuana, why not legalize it?(6) Then patients can take it or not take it the same way they decide to have a drink and we as clinicians won’t be responsible for pretending that we know enough and that there is enough knowledge to recommend it for medicinal purposes.

So, reading this article largely made me frustrated about our national public policy and views regarding science. It also made me wonder about a number of other projects that need to be done: 1. What are Palliative Care clinician’s views about this matter?; 2. What is the use of marijuana in states where it is legal compared to states where it is only legal if prescribed by a physician?; and 3. How does Willie Nelson stay so thin (and look so healthy) given the amounts of marijuana at his concerts?

More Pallimed posts from Bob Arnold can be found here.
More Pallimed journal article reviews can be found here.
More Pallimed posts on marijuana can be found here.

Robert Arnold MD is a palliative care doctor at the University of Pittsburgh and a co-founder of VitalTalk. He loves both high and low brow comedy (The Good Place and Nanette), pop culture (the National Enquirer and Pop Culture Happy hour) and music of all kinds (not opera tho!)


1 Braun IM, Wright A, Petett J, Meyer FL, et al. Medical Oncologists’ Beliefs, Practices, and Knowledge Regarding Marijuana Used Therapeutically: A Nationally Representative Survey Study DOI: 10.1200/JCO.2017.76.1221 Journal of Clinical Oncology 36, no. 19 (July 1, 2018) 1957-1962.

2 Whiting PF, Wolff RF, Deshpande S, et al. Cannabinoids for Medical Use Systematic Review and Meta-analysis. JAMA. 2015;313(24):2456-2473. doi:10.1001/jama.2015.6358

3 The Pennsylvania law regarding medical marijuana includes a research arm. See

4 From . Accessed Sept 26, 2018.

5 Choi NG, DiNitto DM, Marti CM. Nonmedical versus medical marijuana use about three age groups of adults: Association with mental and physical health status. Am J on Addiction. 2017: (26): 697-706

6 Interestingly on the day I wrote this, a Pennsylvania legislature introduced a bill legalizing Marijuana.

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