A National Survey of Marijuana Use Among US Adults With Medical Conditions, 2016-2017

Hongying Dai, Kimber P. Richter

JAMA Network Open, 2019, 2, (9), e1911936.

doi:10.1001/jamanetworkopen.2019.11936

 

Abstract

IMPORTANCE : The number of states legalizing marijuana for medical and recreational use is increasing. Little is known regarding how or why adults with medical conditions use it.

OBJECTIVES : To report the prevalence and patterns of marijuana use among adults with and without medical conditions, overall and by sociodemographic group, and to further examine the associations between current marijuana use and the types and number of medical conditions.

DESIGN, SETTING, AND PARTICIPANTS : This survey study used a probability sample of US adults aged 18 years and older from the 2016 and 2017 Behavioral Risk Factor Surveillance System, a telephone-administered survey that collects data from a representative sample of US adult residents across the states regarding health-related risk behaviors, chronic health conditions, and use of preventive services.

MAIN OUTCOMES AND MEASURES : Current (past month) and daily (20 days in the last 30 days) marijuana use.

RESULTS : The study sample included 169 036 participants (95 780 female [weighted percentage, 52.0%]). Adults with medical conditions had higher odds of reporting current marijuana use than those without medical conditions (age 18-34 years: adjusted odds ratio, 1.8 [95%CI, 1.5-2.1]; age 35-54 years: adjusted odds ratio, 1.4 [95%CI, 1.2-1.7]; age55 years: adjusted odds ratio, 1.6 [95%CI, 1.3-2.0]), especially among those with asthma, chronic obstructive pulmonary disease, arthritis, cancer, and depression. Among those with medical conditions, the prevalence of marijuana use decreased with increasing age, ranging from 25.2%(95%CI, 22.0%-28.3%) for those aged 18 to 24 years to 2.4%(95%CI, 2.0%-2.8%) for those aged 65 years or older for current marijuana use and from 11.2%(95%CI, 8.7%-13.6%) to 0.9%(95%CI, 0.7%-1.2%), respectively, for daily marijuana use. Most adults who used marijuana (77.5%; 95%CI, 74.7%-80.3%), either with or without medical conditions, reported smoking as their primarymethod of administration. Adults with medical conditions were more likely than those without medical conditions to report using marijuana for medical reasons (45.5%[95%CI, 41.1%-49.8%] vs 21.8%[95%CI, 17.8%-25.7%]; difference, 23.7% [95%CI, 17.8%-29.6%]) and less likely to report using marijuana for recreational purposes (36.2% [95%CI, 32.1%-40.3%] vs 57.7%[95%CI, 52.6%-62.9%]; difference, −21.5%[95%CI, −28.1% to 14.9%]).

CONCLUSIONS AND RELEVANCE : This study found that marijuana use was more common among adults with medical conditions than those without such conditions. Notably, 11.2 % of young adults with medical conditions reported using marijuana on a daily basis. Clinicians should screen for
marijuana use among patients, understand why and how patients are using marijuana, and work with
patients to optimize outcomes and reduce marijuana-associated risks.

Key Points

Question : What are the prevalence and patterns of marijuana use among adults with medical conditions?

Findings : This survey study using data from 169 036 participants in the 2016 and 2017 Behavioral Risk Factor Surveillance System surveys found that, compared with adults without medical conditions, adults with medical conditions had a significantly higher prevalence of current and daily marijuana use, were more likely to report using marijuana for medical reasons, and were less likely to report
using marijuana for recreational purposes. Among respondents with medical conditions, 11.2%of young
adults reported using marijuana on a daily basis, and the prevalence of marijuana use decreased with
increasing age.

Meaning : Clinicians should discuss marijuana use with their patients to optimize medical outcomes.

Introduction

Public opinion on marijuana has changed dramatically over the last 2 decades. Support for legalization has doubled since 2010, and currently, 62%of US adults support marijuana use.1 Although marijuana is still classified as a schedule I drug at the federal level, as of June 2019, 33 states and the District of Columbia have legalized 1 or more forms of marijuana; 11 states and the District of Columbia have approved marijuana for both medical and recreational uses.2 In the meantime, current (past-month) marijuana use has increased from 6.2%in 2002 to 9.6%in 2017 among persons aged 12 years or older in the United States.3 In 2017, 24.4 million US adults aged 18 years or older were current users of marijuana; young adults aged 18 to 25 years had the highest prevalence (22.7%).3

Although much policy change has focused on the medical use of marijuana, very little is known regarding whether or how it is actually used for medical purposes, including whether patients are using non-prescribed marijuana for medical purposes (ie, self-medicating) or obtaining marijuana in accordance with physician recommendations. Few studies have examined the characteristics of marijuana users and the prevalence of use among populations with different medical conditions. Those who use marijuana believe that its benefits include pain management, ameliorating chronic conditions such as epilepsy and multiple sclerosis, and relieving anxiety, stress, and depression.4 Current research suggests that both short- and long-term marijuana use are associated with several adverse health outcomes, including respiratory symptoms, cognitive decline, neurological changes, and psychiatric conditions including addiction.5 Other potential long-term health consequences include cancer, chronic obstructive pulmonary disease (COPD), and heart disease.5

A previous study6 found that individuals who used marijuana in the past year were less likely than nonmarijuana users to have diabetes but more likely to have depression. The prevalence of marijuana use was not significantly different among those with and without multiple medical conditions.6 However, that study was limited to marijuana use of middle-aged and older adults (ie, those aged50 years) in the past year.

The fundamental pattern of the use of marijuana among patients with medical conditions remains unknown. Hence, it is not clear how many patients with medical conditions are using marijuana or how they are using it, and this is a critical knowledge gap. Clinicians should know whether marijuana use is prevalent among their patients with chronic illness, to implement screening and counseling regarding potential health risks and benefits. Policy makers should know whether highly vulnerable patient populations are using marijuana to determine whether heightened surveillance is needed to determine the associations of marijuana use with medical care and outcomes.

To begin to address this knowledge gap, we used a probability sample by combining the 2016 and 2017 Behavioral Risk Factor Surveillance System (BRFSS) surveys—the nation’s largest health survey—to assess the prevalence of current (past-month) and daily (20 days in the last 30 days) marijuana use across key sociodemographic groups.We further examined the associations between current marijuana use and the types and number of medical conditions, stratified by 3 age groups (18-34, 35-54, and55 years). This study also determined the method of administration by which participants primarily use marijuana and assessed whether they used marijuana for medical or recreational purposes.

(…)

dai_2019_oi_190456