Canadian Medical Association journal最新文献

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.

Background: During the 2023 wildfire season, Ontario, Canada, had unprecedented wildfire smoke, but the health impact on the population is unknown. We aimed to quantify the acute impact of the wildfire smoke on respiratory and cardiovascular outcomes across Ontario.

Methods: We conducted a quasi-experimental study by leveraging the timing of 2 consecutive wildfire smoke episodes in June 2023. Heavy wildfire smoke blanketed much of Ontario on 2 occasions, in early June and again in late June, causing severely degraded daily air quality. Following the epidemiologic triangulation framework, we collected health data on emergency department visits for 4 outcomes (asthma-related causes, other respiratory causes, ischemic heart disease, and non-cardiorespiratory causes) from Ontario's real-time syndromic surveillance system and the National Ambulatory Care Reporting System. We also employed different epidemiologic methodologies, including interrupted time-series and case-crossover analyses.

Results: After the initial heavy wildfire smoke in early June 2023, daily asthma-related visits increased substantially across Ontario, peaking at a 23.6% increase (95% confidence interval 13.2%-34.9%) at a 1-day lag and lasting up to a lag of 5 days after the start of the smoke episode. The later episode of heavy smoke, despite causing higher exposures, had a reduced effect on asthma-related visits. We did not detect any effect on other outcomes in either episode. These findings were consistent across different methodologies and data sources. Post hoc analysis revealed that asthma-related visits were briefly elevated after the wildfire smoke among children (40% higher), but we observed a more sustained effect among adults (48% higher, lasting 1 week).

Interpretation: The 2023 wildfires substantially increased asthma-related emergency department visits in Ontario, with age and timing of exposure being important factors influencing the impact. As wildfires emerge as one of the fastest-growing environmental risk factors globally, future research should identify and evaluate measures to effectively mitigate the acute health impacts of wildfire smoke.