Grant: Travel Awards - Institute Community Support

Prescription opioid use and overdose has steadily increased over the past two decades, resulting in a dramatic increase in opioid poisoning-related emergency department (ED) visits and hospitalizations. The purpose of this study is to assess post-discharge opioid prescriptions and dispensations in medical and surgical patients, and to identify potential patterns of planned and unplanned health service use. Patients admitted to a tertiary care teaching hospital in Montreal (2014 - 2016) were part of a cohort randomized to the RightRx study which evaluated the impact of electronically enabled medication reconciliation software on adverse drug events. Patients were included if there were =>18 years at admission, not transferred from another hospital, having a continuous health insurance coverage (RAMQ), and discharged alive to the community. RAMQ health administrative claims were used to measure opioid dispensations in the 1-year prior to and post discharge, as well as hospital re-admissions and ED visits. Patient characteristics and discharge prescriptions were obtained from the hospital chart. Time-varying use of opioids after discharge will be modeled as: 1) current use, 2) continuous duration of use, and 3) cumulative duration of use. For the main analyses, marginal structural models will be used to model the association between use of opioids and risk of emergency department visits and hospitalizations. Inverse probability of treatment and censoring weights will be constructed to properly adjust for the time-fixed and time-varying confounders that may be unbalanced between the opioid and non-opioid users as well as to account for competing risk due to mortality. Reasons for the re-admissions will also be presented as part of the analyses. All analyses will be adjusted for a number of important covariates including patient comorbidities, medication history and healthcare system characteristics such as nurse-to-patient and attending physician-to-patient ratios.