Initial Patterns of Prescription Opioid Supply and Risk of Mortality Among Insured Adults in the United States
OBJECTIVE: To examine the association between initial patterns of prescription opioid supply (POS) and risk of all-cause mortality among an insured opioid-naïve patient population in the United States (US). METHODS: This retrospective observational cohort study used de-identified, administrative health care claims data from a large national insurer (Optum Clinformatics Data Mart) from 2010 to 2015. Participants included insured, cancer-free adults prescribed opioid analgesics. Prescription opioids received during the first 6 months of therapy were used to categorize initial patterns of POS as daily or nondaily. Cox regression was used to estimate the association of initial patterns of POS with all-cause mortality within one year of follow-up, adjusting for baseline covariates to control for confounding. RESULTS: A total of 4,054,417 patients were included, of which 2.75% had incident daily POS; 54.8% were female; median age was 50 years; mean Charlson comorbidity index (CCI) was 0.21 (standard deviation = 0.77); and mean daily morphine milligram equivalent was 34.61 (95% confidence intervals: 34.59, 34.63). There were 2068 more deaths per 100,000 person-years among patients who were prescribed opioids daily than nondaily. After adjusting for baseline covariates, the hazard of all-cause mortality among patients with incident daily POS was nearly twice that among those prescribed nondaily (hazard ratio [HR] = 1.94; 95% confidence intervals: 1.84, 2.04). CONCLUSIONS: Among insured adult patients with noncancer pain, incident chronic POS was associated with a significantly increased risk of all-cause mortality over at most 1 year of follow-up. Because these results may be susceptible to bias, more research is needed to establish causality.