Long-term opioid prescribing and the incidence of opioid-related hospitalizations or emergency department visits among patients with metastatic cancer.

200 Background: Many patients with metastatic cancer experience cancer-related pain which is commonly managed using opioids. Although opioids are an effective tool for cancer pain management, their use can result in adverse effects which may be related to long-term use and are understudied in this population. Therefore, we aimed to describe long-term opioid prescribing (LTOP) practices among patients with metastatic cancer and investigate the incidence of opioid-related hospitalizations and emergency department (ED) visits among recipients of long-term prescribing. Methods: This retrospective cohort study used population-based data from Alberta, Canada to identify patients diagnosed with stage IV cancers between 2004-2017 who had at least 1-year of follow-up and were opioid naïve at diagnosis. LTOP was defined as receipt of a ≥90-day supply of opioids with less than a 30-day gap in supply within a 180-day period. Prescribing practices were characterized according to timing (early vs. end-of-life EoL onset), morphine equivalent dose, duration, and concurrent medication use. The EoL phase of disease was defined as the year preceding death. The incidence rate of opioid-related encounters was compared between different characteristics of LTOP. Results: The study included a total of 10927 patients, 2521 (23%) of whom received long-term opioid prescribing after diagnosis. LTOP became more common as patients approached EoL, with most patients (53%) having LTOP initiated only within their last year of life. 85 patients (3.4%) experienced an opioid-related hospitalization or ED visit after initiation of LTOP, with an incidence rate of 2.36 (95% CI 1.92, 2.86) encounters per 100 person-years. Higher opioid dosage and concurrent prescribing of anxiolytics, benzodiazepines, antidepressants, and neuroleptic medications were significantly associated with a higher incidence of opioid-related encounters. Conclusions: Long-term opioid prescribing is commonly experienced by patients living with metastatic cancer as a chronic disease. The concurrent use of psychoactive drugs during LTOP was associated with experiencing opioid-related hospitalizations/ED visits.