Juan Esteban Perez, M.D.

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The problem: As with all treatments, medicinal cannabis has an evidence base to guide its appropriate use.  That evidence base includes studies and consensus guidelines that define the conditions for which cannabis and cannabinoids are believed to be effective, and, if so, whether it should be used as first-line treatment or only if other treatments fail.  Granted, that evidence base is not as well-developed as it should be, but that evidence does exist.  However, little is known about how well clinical recommendations agree with the evidence, such as it is.

 

Why do this study? There are two reasons to determine whether physicians’ recommendations are consistent with the evidence.  First, over-prescribing relative to the evidence could suggest a need for more and better physician education.  That’s the main premise of this study.  But there’s a second reason to examine consistency.  If physicians, based on their clinical experience, are making recommendations to use cannabis when the evidence doesn’t support doing, so, it’s possible that those physicians may be ahead of the evidence.  That is maybe those physicians are seeing real benefits that haven’t been adequately studied yet.

 

The study:  This study was conducted in a private clinic that independently assesses the validity of medical claims for third party insurance companies. Patients seeking insurance coverage for cannabis prescriptions were referred to the clinic as part of a standard prescription review. Guidelines from the College of Family Physicians of Canada regarding marijuana use for chronic pain or anxiety were used as the gold standard. A total of 61 patients were prescribed cannabis due to chronic pain and underwent a comprehensive evaluation by an orthopedic surgeon and physical medicine specialist. An additional 9 patients were prescribed cannabis due to post-traumatic stress disorder (PTSD) and were evaluated by a psychiatrist. All patients completed survey instruments and asked to provide a voluntary urine sample (to corroborate substance use). Medical history was evaluated for indications as well as potential contraindications (age < 25 years old, personal or family history of psychosis, history of cannabis or other substance abuse, respiratory disease, cardiovascular disease, pregnancy or breastfeeding).

 

According to the College of Physicians guidelines, indications for cannabis use in chronic pain disorders include refractory chronic pain of neuropathic origin (non-responsive to cannabinoid alternatives), cancer pain, and palliative care. Only 8 of 61 patients fit these guidelines. 43 of the cases were not attributed to a neuropathic cause, while non-cannabinoid trials did not occur in 44 of the patients. 46 of the patients had contraindications to cannabis prescription. Regarding PTSD, none of the 9 patients had tried first-, second-, and third-line treatments, and 3 had contraindications to cannabis use.

 

Conclusions: This study found that only a small fraction of cannabis prescriptions followed one set of relevant guidelines.

 

What does this study add? As far as we know, this is the first study that examines the concordance of cannabis prescribing with an existing guideline. However, the small sample size limits the generalizability of the conclusions drawn. Also, it’s important to keep in mind that the ‘gold standard’ in this case—guidelines from the College of Family Physicians of Canada—should, like virtually all guidelines, be viewed as one viewpoint.  Moreover, guidelines can and should chance as additional evidence is gathered.. Research regarding medicinal cannabis is still in its early stages, and the full indications and contraindications are yet to be firmly established. Despite the limitations of the study, this study suggests that in many cases, physician recommendations are at odds with at least one set of guidelines.

 

Funder: This research was funded in part by the Scientific Research and Experimental Development tax incentive program from the government of Canada.

 

Author Conflicts: Dr. Elias is Chief Executive Officer and Chief Medical Officer of Canadian Health Solutions Inc and provides assessment of the effects of prescribing, including of cannabis, to institutional insurers in Canada. The other authors are all employed by Canadian Health Solutions Inc.

 

Commentary:  As far as I know, this is the first study looking at what physicians recommend, and whether their recommendations are consistent with the evidence base for medical cannabis. If physician prescribing really is at odds with the evidence, then we need to know that.  But I wouldn’t conclude that, just because physicians prescribe for more indications that the guidelines approve, or if they turn to cannabis before other options are tried, that the physicians are therefore wrong.  Their recommendations may be inconsistent with guidelines, but the evidence base for cannabis is changing quickly.  (That, in a nutshell, is why we started MJResults.org).  So what if these physicians are actually right, and the guidelines are wrong?  What if these physicians are seeing benefits in their patients, and changing their recommendations accordingly?  From this study we don’t know the answers to those questions.  Indeed, we may not know for years.  But before we turn to the obvious conclusion of providing better training for physicians, we should at least consider the possibility that these physicians—or at least some of them—know something that the authors of these guidelines don’t know.