Abstract
Dear Editor:
Introduction
In the United States, 16 states and the District of Columbia have legalized marijuana for certain qualifying medical conditions, and efforts are underway to legalize marijuana for medical purposes elsewhere; yet the demographics of registered users has not been extensively studied.1,2 The objective of this study is to determine the characteristics of persons enrolled in state-administrated medical marijuana programs in the United States.
Methods
In June 2011 the websites of state-administered medical marijuana programs were reviewed and the number of patients enrolled, qualifying condition, age, and gender were obtained. If registration data were not available online, the state registry was contacted by phone and email on two separate occasions. States where registration is not mandatory were excluded from analysis. Marijuana registrants were assumed to be 18 years old or older unless otherwise specified. State populations from the 2010 census were used to calculate marijuana registration prevalence, and comparisons between states were made with a chi-square test. Statistical analysis was performed using StatXact 3.0 (Cytel Software Corporation, Cambridge, MA). No identifying protected health information was obtained and only publicly available data were used.
Results
At least 286,243 people are registered for medical marijuana in the United States (Table 1). Washington State does not have a registry, registration is voluntary in California, and Hawaii's data are not public. Washington, D.C., New Jersey, and Delaware had not started administering their programs as of this study. These jurisdictions were excluded from analysis. The average age of persons registered in Colorado and Montana are 40 and 41 years, respectively. Montana, Nevada, and Rhode Island report registrants by age groups. In these five states 99.9% (165,913/166,013) of patients are adults. Gender is reported only in Arizona and Colorado, where the majority of registered persons are male, 75.4% and 69%, respectively. The most common qualifying condition for medical marijuana is severe or chronic pain (92.2%) followed by muscle spasms (21%) and nausea and vomiting (12.3%). Posttraumatic stress disorder is a qualifying condition only in New Mexico, where it is also the leading indication (38.5%). There is a significant difference (p<0.001, chi-square) in the fraction of state adult populations that is registered for medical marijuana, ranging from 4.1% (Montana) to 0.07% (Vermont).
p<0.001 for a difference in the percent of state adult populations registered for medical marijuana. Persons may have multiple qualifying indications for medical marijuana, so the total percent of patients may exceed 100%. †All patients are assumed to be adults if not otherwise specified by the state registry. ‡Montana has overlapping categories (i.e., pain, nausea, and pain and nausea). In such cases persons were assigned to both categories. Montana does not discriminate between HIV/AIDS and cancer in its registry, so the same entry was made for both categories. *Rhode Island recently started registering enrollees by qualifying condition and the data were not complete for this study. PTSD: Post traumatic stress disorder.
Discussion
The majority of persons registered for medical marijuana in the United States appear to be young, male, and registered for severe or chronic pain. Interestingly, there is a significant difference in the percent of each state's adult population that is registered for marijuana. Possible explanations for this divergence include differences in overall disease burden, social acceptance of marijuana usage, and ease of medical marijuana registration and acquisition. For example, Montana and Colorado have or have had expansive dispensary systems.3,4 This analysis is limited by a lack or limited data from several states and likely underrepresents the total number of persons using marijuana for medical purposes in the United States. These data should be considered in further policy decisions regarding medical marijuana.
Footnotes
Acknowledgments
I thank Allan Prochazka, MD for statistical guidance and Christian Thurstone, MD and Antonio Jimeno, MD, PhD for critical evaluation of the manuscript.
Author Disclosure Statement
No competing financial interests exist.
Funding
None
Disclaimer
The content is solely the responsibility of the author and does not necessarily represent the official views of the State of Colorado.