The effects of a provincial opioid prescribing standard on prescribing for pain in adults: an interrupted time-series analysis.

BACKGROUND

In 2016, the College of Physicians and Surgeons of British Columbia released a legally enforceable opioid prescribing practice standard for the treatment of chronic noncancer pain (CNCP); it was revised in 2018 in response to concerns that it was misinterpreted. We aimed to test the effects of the practice standard on access to opioids for people treated for CNCP, living with cancer, or receiving palliative care.

METHODS

We used comprehensive administrative health data from Oct. 1, 2012, to Mar. 31, 2020, and multiple baseline interrupted time-series analysis to evaluate the effects of the 2016 practice standard and 2018 revision in cohorts of people treated for CNCP, living with cancer, or receiving palliative care.

RESULTS

The 2016 practice standard accelerated pre-existing monthly trends in morphine milligram equivalents (MME) dispensed per person treated for CNCP (-0.1%, 95% confidence interval [CI] -0.2% to 0.0%), but also for people living with cancer (-0.7%, 95% CI -1.0% to -0.5%) and those receiving palliative care (-0.3%, 95% CI -0.5% to 0.0%). The proportion of people with CNCP prescribed a daily dose greater than 90 MME (-0.3%, 95% CI -0.4% to -0.2%), coprescribed a benzodiazepine or other hypnotic (-0.6%, 95% CI -0.7% to -0.5%), and aggressively tapered (-0.1%, 95% CI -0.2% to 0.0%) also decreased more quickly after the practice standard. Although we observed null or decreases in level effects overall, the proportion of people aggressively tapered increased 2.0% (95% CI 0.4% to 3.3%) immediately after implementation of the practice standard. Trends slowed or reversed after the 2018 revision.

INTERPRETATION: The 2016 practice standard was associated with an immediate and long-lasting effect on physicians' opioid prescribing behaviours, including inadvertently increasing aggressive tapering (observed level effect) and reducing access to opioids for people living with cancer or receiving palliative care.