Toward a Patient Registry for Cannabis Use: An Exploratory Study of Patient Use in an Outpatient Health-Care Clinic in Oregon.

State level initiatives legalized and or decriminalized non-medical marijuana use in Colorado, Washington, Oregon, Alaska, the District of Colombia, California and Nebraska. Twenty-eight other states and the District of Columbia allow medical cannabis use. Nationally, cannabis use more than doubled between 2001–2002 and 2012–2013 with corresponding increases in cannabis use disorders (Hasin DS et al. 2015). Given changing laws, usage and attitudes toward cannabis, concerns are being raised about the impacts policy changes may have on individual and community health and well-being (Lipari, Kroutil, and Pemberton 2016; Volkow ND et al. 2016). Cannabis contains numerous cannabinoids; its use has been associated with both health risks and benefits (Hill 2015). Studies suggest that use of cannabis can negatively affect respiratory function and cardiovascular function, and may interact with prescribed medications (Hall and Degenhardt 2009; Jones 2002; Mittleman et al. 2001; Owen, Sutter, and Albertson 2014; Polen et al. 1993; Tashkin 2013; Thomas, Kloner, and Rezkalla 2014). Additionally, data suggest that the use of cannabis is associated with other substance use disorders (Blanco C et al. 2016). On the other hand, cannabis may help individuals with chronic pain, neuropathic pain and spasticity due to multiple sclerosis (Whiting PF et al. 2015; Hill 2015). There is, however, little prospective, longitudinal data on the health, and healthcare utilization associated with chronic cannabis use. A patient registry of cannabis users linked with their electronic health records could provide insights into the medical benefits and consequences associated with cannabis use. A patient registry is “an organized system that uses observational study methods to collect uniform data (clinical and other) to evaluate specified outcomes for a population defined by a particular disease, condition, or exposure, and that serves one or more predetermined scientific, clinical, or policy purposes” (Gliklich, Dreyer, and Leavy 2014). Patient registries provide the opportunity to conduct research on patient outcomes related disease, condition, exposures, or product use. Registry information differs from clinical trials in that it relies on electronic health records which capture patient data, and facilitates investigation of associations with healthcare utilization and health outcomes. Patient registries played a critical role in the generation of evidence regarding cigarette smoking and lung cancer, as data documented high rates of lung cancer prevalence in smokers (Jemal et al. 2013), declining incidence rates of cancer in states with declining rates of users (Centers for Disease Control and Prevention (CDC) 2011; Cokkinides et al. 2009; Jemal et al. 2003; Pierce et al. 2010), and the overall declines of smoking rates and lung cancer rates (Centers for Disease Control and Prevention (CDC) 2011). Evidence of the harms of tobacco promoted policy changes that improved population health. The creation of a patient registry, however, is a complex task. When creating a registry for a product that has myriad forms and methods of use such as cannabis, it is critical to begin early in the registry development process with an ethnographical approach that investigates the kinds of questions (and response options) that are relevant within the registry. Without a thorough understanding of patients’ reasons for use, perceived effects and routes of administrations, registry variables may reflect a researcher’s antiquated or ill-informed conceptions of modern cannabis use. As legalization spreads across the country, it is likely that patient cannabis registries linked to electronic health records may be developed to assess long-term consequences of cannabis use. Additionally, because non-medical cannabis users may differ from medical cannabis users, it is important to also develop cannabis use registries in communities where non-medical use is permitted. To begin the development of a cannabis use registry in Oregon, a small sample of users were interviewed to better understand patient perspectives about their motivations for using cannabis, methods of use, perceptions about benefits, and concerns about risks.