Prospective Investigation of Factors Associated with Prescription Opioid Dose Escalation among Patients in Integrated Health Systems.

BACKGROUND Prior research has identified factors associated with prescription opioid initiation, but little is known about the prevalence or predictors of dose escalation among patients already prescribed long-term opioid therapy (LTOT). OBJECTIVE This was a 2-year prospective cohort study to examine patient and clinician factors associated with opioid dose escalation. DESIGN A prospective cohort study. Participants were seen at baseline and every 6 months for a total of 2 years. PARTICIPANTS Patients prescribed a stable dose of LTOT for musculoskeletal pain were recruited from two integrated health systems (Kaiser Permanente and the Department of Veterans Affairs, respectively). MAIN MEASURES The prescription opioid dose was based on pharmacy records and self-report. Administrative data were gathered on characteristics of the opioid-prescribing clinician and healthcare utilization. Participants completed measures of pain, functioning, and quality of life. KEY RESULTS Of enrolled participants (n = 517), 19.5% had an opioid dose increase. In multivariate analyses, patient variables associated with dose escalation were lower opioid dose (hazard ratio [HR] = 0.86, 95% confidence interval [CI] = 0.79-0.94, for every 10-mg increase in baseline dose) and greater pain catastrophizing (HR = 1.03, 95% CI = 1.01-1.05). Other variables associated with dose escalation were as follows: receiving medications from a nurse practitioner primary care provider (HR = 2.10, 95% CI = 1.12-3.96) or specialty physician (HR = 3.18, 95% CI = 1.22-8.34), relative to a physician primary care provider, and having undergone surgery within the past 6 months (HR = 1.80, 95% CI = 1.10-2.94). Other variables, including pain intensity, pain disability, or depression, were not associated with dose escalation. CONCLUSIONS In this 2-year prospective cohort study, variables associated with opioid dose escalation were lower opioid dose, higher pain catastrophizing, receiving opioids from a medical specialist (rather than primary care clinician) or nurse practitioner, and having recently undergone surgery. Study findings highlight intervention points that may be helpful for reducing the likelihood of future prescription opioid dose escalation.