UC Davis

Objective

To identify patient factors and health care utilization patterns associated with dose escalation during the first year of long-term opioid therapy for chronic pain.

Design

Retrospective cohort study using electronic health record data.

Setting

University health system.

Subjects

Opioid naïve adults with musculoskeletal pain who received a new outpatient opioid prescription between July 1, 2011 and June 30, 2012 and stayed on opioids for 1 year.

Methods

Mixed-effects regression was used to estimate patients' rate of opioid dose escalation. Demographics, clinical characteristics, and health care utilization for patients with and without dose escalation were compared.

Results

Twenty-three (9%) of 246 patients in the final cohort experienced dose escalation (defined as an increase in mean daily opioid dose of ≥30-mg morphine equivalents over 1 year). Compared with patients without dose escalation, patients with escalation had higher rates of substance use diagnoses (17% vs 1%, P = 0.01) and more total outpatient encounters (51 vs 35, P = 0.002) over 1 year. Differences in outpatient encounters were largely due to more non face-to-face encounters (e.g., telephone calls, emails) among patients with dose escalation. Differences in age, race, concurrent benzodiazepine use, and mental health diagnoses between patients with and without dose escalation were not statistically significant. Primary care clinicians prescribed 89% of opioid prescriptions.

Conclusions

Dose escalation during the first year of long-term opioid therapy is associated with higher rates of substance use disorders and more frequent outpatient encounters, especially non face-to-face encounters.