Chronic Pain the Top Reason US Patients Seek Medical Marijuana

Chronic pain accounted for 62.2% of all patient-reported qualifying conditions under which US patients sought medical marijuana, according to a new paper in Health Affairs.

The research compared state registry data with evidence from the 2017 National Academies of Sciences, Engineering and Medical report on cannabis. The report found that 85.5% of patient-reported qualifying conditions (chronic pain, nausea, and vomiting stemming from chemotherapy, as well as multiple sclerosis spasticity symptoms) were backed up by either conclusive or substantial evidence of marijuana’s effectiveness for those conditions, the University of Michigan researchers reported.

Interestingly, the authors found that fewer than half the states had data on patient-reported qualifying conditions; just 20 reported data on the number of registered patients.

In an interview with The American Journal of Managed Care®, Kevin F. Boehnke, PhD, a researcher in anesthesiology, said the findings aligned with the hypothesis that the proportion of medical cannabis licenses granted for these conditions would line up with the reported efficacy of cannabis, as well as the prevalence of that condition.

After chronic pain, the next 2 common patient reported qualifying conditions were multiple sclerosis spasticity symptoms, followed by chemotherapy-induced nausea and vomiting, posttraumatic stress disorder, and cancer. Patient-reported qualifying conditions are reported medical conditions that allow a person to get a medical cannabis license.

Since 1996, 33 states and the District of Columbia have legalized cannabis for medical reasons, and 10 have legalized it for recreational use.

The data that is collected varies widely, and some states are more stringent than others. Twenty states and the District of Columbia had registry data on patient conditions, and 15 states had data on patient-reported qualifying conditions. California and Maine collect minimal or no data on voluntary registries, but Arizona and Colorado publish detailed reports. Three states had missing data because they do not publish reports every year: Michigan, Montana, and Rhode Island. Connecticut does not publish reports at all.

In addition, the number of licensed medical users was likely far lower than the actual number of users. In 2016, there were 641,176 thousand registered medical marijuana patients. There were 813,917 registered patients in 2017.

Boehnke said he and his coauthors were surprised to see how prevailing chronic pain was as a medical condition for people seeking cannabis for medical treatment.

“We thought that we would see a lot of chronic pain, just given how common it was, plus the fact that it can be a standalone condition like fibromyalgia, as well as a symptom in many conditions like cancer or multiple sclerosis,” he said. “But the fact that it was just so overwhelmingly dominating, I guess we might call that a little bit surprising.”

Boehnke said there are multiple reasons as to why chronic pain was the dominate rationale for those seeking to use medical marijuana. Beside the fact that it is extremely common—about 100 million Americans say they have chronic pain—he said pain is a “very, very, very open-ended diagnosis for somebody to get a medical cannabis license. It doesn't have the same kind of the stringent diagnostic criteria as other things.”

He added that another reason why chronic pain is probably a dominating condition for cannabis prescription is because “chronic pain is very challenging to manage and treat effectively.”

Medical cannabis data reflects that challenge, such as the fact that medications indicated for chronic pain don’t always work, and they come with unpleasant side effects or carry the risk of addiction, such as opioids.

“There's a lot of interest among people with chronic pain in testing something different that they perceive to be safer and an alternative,” Boehnke said.

He said there needs to be more research on patient reports that marijuana provides better symptoms relief and fewer side effects, including better data on formulations and administration methods. In addition, Boehnke and his co-authors would like to see cannabis removed as a Schedule I substance by the Drug Enforcement Administration. Schedule I means a substance has no medical use and has a high potential for abuse; because of the classification it is difficult to conduct clinical trials on marijuana.

Ideally, the researchers would like to see a nationwide database of medical marijuana patients, where one could combine information from a patient registry with data from clinical trials.

“We’re in a time where the policy is far ahead of the science,” said Boehnke.

Reference

Boehnke KF, Gangopadhyay S, Clauw DJ, Haffajee RL. Qualifying conditions of medical cannabis license holders in the United States. Health Aff (Millwood). 2019;38(2):295-302.