Receipt of preventive health services and current cannabis users

Substance use is associated with greater barriers and reduced access to care. Little research, however, has examined the relationship between cannabis use and receipt of preventive health services. Using data from the 2017 Behavioral Risk Factor Surveillance System, we examined the association between current cannabis use and receipt of 12 preventive health services, adjusting for sociodemographic characteristics and access to care. In analyses that adjusted for sociodemographic factors and access to care, participants with current cannabis use had lower odds of being vaccinated for influenza (AOR = 0.67, 95% CI = 0.54–0.83) and higher odds of ever receiving HPV vaccination (AOR = 1.77, 95% CI = 1.06–2.96) and HIV screening (AOR = 2.34, 95% CI = 1.88–2.92) compared with those without cannabis use. Among the 12 preventive services examined, we found three differences in receipt of preventive services by cannabis use status. Cannabis use does not appear to be associated with significant underuse of preventive services.


Introduction
Cannabis is legal for some form of use in 33 states and Washington, D.C. Legalization has been accompanied by increased cannabis use. Between 2001Between -2002Between and 2012Between -2013 year cannabis use doubled from 4.1% to 9.5% in U.S. adults. 1 A 2017 study found that approximately 15% and 8% of U.S. adults had used cannabis in the past year and past 30 days, respectively. 2 Prior research has demonstrated that heavy use of alcohol and/or drugs is associated with greater barriers and reduced access to health care. 3 No studies to date have examined the association of cannabis use with access to care. Cannabis has adverse neurocognitive effects, including decreased functional connectivity, activity, and volume in regions of the brain associated with learning, memory, and inhibitory control. 4 Persistent cannabis use is associated with memory problems, difficulty managing activities of daily living, and amotivation. 5,6 Cannabis use also has mental health effects, including an association with psychosis, treatment relapse for depression, and avoidance of social situations in those with social anxiety. 4,7 The social, neurocognitive, and mental health effects of cannabis may be associated with less engagement with health care services. Little research, however, has examined the relationship between cannabis use and health promoting behaviors such as obtaining preventive care. Therefore, in this study, we examined the association of current cannabis use with receipt of preventive health services.

Methods
We used data from the 2017 Behavioral Risk Factor Surveillance System (BRFSS). We included states that participated in both the optional Marijuana Module and other optional modules on cardiovascular health, vaccinations, alcohol screening, and diabetes. Our predictor was current cannabis use, as assessed by the question "During the past 30 days, on how many days did you use marijuana or hashish?" We examined uptake of 12 preventive services, including cardiovascular risk reduction strategies, vaccinations, health behavior screenings, and diabetes care ( Table 2). We used recommended guidelines from the U.S. Preventive Services Task Force (USPSTF), the Centers for Disease Control and Prevention (CDC), or the American Diabetes Association (ADA) to determine eligible participants ( Table 2). Using chi-squared statistics and logistic regression, we examined whether participants who had used cannabis in the past 30 days were more or less likely than those who did not use cannabis to receive preventive health services. We adjusted for sociodemographic characteristics, including age, sex, race/ethnicity, employment, education, marital status, and access to care (insurance status and having a personal doctor).
The 2017 BRFSS data are publicly available and exempt from Institutional Review Board approval.

Results
Overall, 56,924 individuals (unweighted) were included, representing 45,655,241 U.S. adults. Of those, 10.7% reported current cannabis use. Participants with cannabis use were more likely to be younger, male, unmarried, and non-Hispanic white and had fewer comorbidities compared to those who did not use cannabis (Table 1). Additionally, those with current cannabis use were less likely than those who did not use cannabis to have health insurance (84.9% vs. 88.9%, p = 0.002) or a personal doctor (64.7% vs. 78.5%, p < 0.001).
In analyses that adjusted for sociodemographic factors and access to care, participants with current cannabis use had lower odds of being vaccinated for influenza in the past year (adjusted odds ratio [AOR] = 0.67, 95% confidence interval [CI] = 0.54-0.83) and higher odds of ever receiving HPV vaccination (AOR = 1.77, 95% CI = 1.06-2.96) and HIV screening (AOR = 2.34, 95% CI = 1.88-2.92) compared with those without cannabis use. There were no statistically significant differences in receipt of serum cholesterol, alcohol use, or diabetes screenings between participants with and without current cannabis use in adjusted analyses.

Discussion and conclusions
We examined the relationship between current cannabis use and receipt of preventive services. Among the 12 services examined, participants with current cannabis use were less likely to receive influenza vaccination but more likely to receive HPV vaccination and HIV screening than those who did not use cannabis. Prior analyses have shown that those who use cannabis are more likely to engage in unprotected sex. 8 This difference in health behaviors may explain why they were more likely to receive HPV vaccination and HIV screening. We also found that participants with cannabis use were less likely to have insurance coverage suggesting that access to care may also be a factor in the association between cannabis use and receipt of preventive care services.
Some limitations are noted. This study was limited to individuals in 10 states and Washington, D.C. who participated in the Marijuana Module and other select optional modules in 2017, thus potentially limiting the overall generalizability of our findings. However, the states that were included are geographically diverse. Receipt of preventive services are also by self-report. Cannabis use information was limited to the past 30 days, so we were unable to assess the relationship between cumulative cannabis use and receipt of preventive health services. Additionally, we included participants in our analysis who reported any cannabis use in the past 30 days, which may explain why we found little association between cannabis use and receipt of preventive services. An analysis limited to daily use in the past 30 days may demonstrate a different relationship. Finally, we did not account for the use of other substances in the analysis. However, this is an important relationship to examine in future work as people with more frequent cannabis use are more likely to use other substances 9 and use of other substances is associated with lower likelihood of receiving preventive health services. 10 In conclusion, among the 12 preventive measures identified, we found three differences in receipt of preventive health services by cannabis use status. Current cannabis use does not appear to be associated with significant underuse of preventive services.

Conflicts of interest
Research reported in this publication was supported by the National Institute on Aging of the National Institutes of Health under Award Number R01AG058678. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. b "The USPSTF recommends the service. There is high certainty that the net benefit is moderate or there is moderate certainty that the net benefit is moderate to substantial" or "Supportive evidence from well-conducted cohort studies or Supportive evidence from a well-conducted case-control study" (ADA).
c "The USPSTF recommends selectively offering or providing this service to individual patients based on professional judgment and patient preferences. There is at least moderate certainty that the net benefit is small" or "Supportive evidence from poorly controlled or uncontrolled studies or Conflicting evidence with the weight of evidence supporting the recommendation" (ADA).
d "The USPSTF recommends the service. There is high certainty that the net benefit is substantial" or "Clear evidence from well-conducted, generalizable, randomized controlled trials that are adequately powered or Supportive evidence from well-conducted randomized controlled trials that are adequately powered or Compelling nonexperimental evidence" (ADA