Purpose: Concerns around chronic opioid use (COU), misuse, and harms have led to increased scrutiny of opioid prescribing in oncology. There is lack of research examining patient-level factors associated with COU. Our aim was to examine patient-level factors associated with COU in newly diagnosed cancer patients.
Methods: Population-based retrospective cohort study using administrative health data of patients in Alberta, Canada, diagnosed between February 2016 and October 2017. Adult cancer patients who completed a symptom survey within ± 60 days of diagnosis were included. Patients were divided into two groups: COU (defined as continuous opioid prescriptions for at least 90 days post-diagnosis) and non-chronic opioid use (NCOU). Logistic regression was used to evaluate factors associated with COU.
Results: We included 694 patients (mean age 65 years; 51% female). Most had breast (20%), colorectal (13%), and lung (33%) cancers. Of the 14% with COU, 79% were opioid naïve at diagnosis. Those in the COU group were more often diagnosed with advanced cancer (66% versus 40%), had lung cancer (47%), and were opioid tolerant (> 90 days of continuous opioids within one-year pre-diagnosis). A total of 64% of COU versus 27% of NCOU had moderate to severe pain at diagnosis (p < 0.001). Irrespective of treatment type or stage, those with moderate to severe pain, were opioid tolerant at diagnosis, or had multiple prescribers were at greater risk for COU.
Conclusions: Specific patient groups were at increased risk of COU and should be the focus of adaptive prescribing approaches to ensure that opioid use is appropriate.
Keywords: Cancer; Chronic opioid use; Cohort study; Opioids; Symptom management.