Rule changes designed to reduce opioid overdose deaths in British Columbia in 2016 inadvertently harmed cancer and palliative-care patients by reducing their access to pain killers, a new study has found.
The study published this week in the Canadian Medical Association Journal describes the impact of a practice standard issued by the College of Physicians and Surgeons of B.C. that June, about two months after the province declared a public health emergency over opioid deaths.
The rule changes were designed to mitigate prescription drug misuse, including the over-prescribing of opioids among patients with chronic non-cancer related pain.
The rules weren't meant for cancer and palliative-care patients, but lead author Dimitra Panagiotoglou said there was a "spillover" effect as doctors applied "aggressive tapering" of the painkillers.
"(With) the ongoing messages that physicians were getting at the time — opioids being bad — individuals decided to pull back on their prescribing, but there was this larger population-level effect in doing so," she said.
"We focus on these two groups because far and wide, it's considered completely acceptable to prescribe opioids for these groups and the concerns around opioids are very different," she said of cancer and palliative-care patients.
There were already downward trends in opioid prescriptions for people with chronic non-cancer pain and those receiving palliative care, Panagiotoglou said, and the study shows that trend continued after the change.
But among cancer patients, there was a surprising "nose dive" in access to opioids right after the release of the new standard, said Panagiotoglou, who is an associate professor in the department of epidemiology, biostatistics and occupational health at McGill University.
The rules were legally enforceable, and physicians found non-compliant could be disciplined or fined under the Health Professions Act and College of Physicians and Surgeons of BC bylaws. The rules were revised in 2018 to address concerns that they were being misinterpreted.
The changes in 2016 set a recommended dose ceiling at 90 morphine milligram equivalents or less per day and used "strong language" around co-prescribing with benzodiazepines given the drug poisoning risk, Panagiotoglou said.
Among cancer patients, the study found opioid dispensations were 15 per cent lower per person than expected two years after the implementation of the 2016 rules. Over 30 days, that translates to 4.5 fewer days of supply, it says.
For people receiving palliative care, the per-person dosage was 6.1 per cent lower, translating to 1.8 fewer days' supply, the study says, while for patients with chronic non-cancer pain — the target population of the rules — dispensations were 8.2 per cent lower.
"Over time, people were seeing a meaningful decline in their doses and in the days supplied," Panagiotoglou said of the period between the implementation of the 2016 practice standard and its revision in 2018.
The study did not include opioids dispensed in hospitals or long-term care facilities, rather for prescriptions for people living at home.
The study says the changes led doctors to increase "aggressive tapering" of patients' medication. Panagiotoglou said evidence suggests this can lead to pain and increase in overdose risk by pushing people toward illicit opioids.
The B.C. college revised its standard in 2018 in response to concerns that misinterpretation was leading to "more conservative prescribing to all patients," not just those with chronic non-cancer pain, the study says.
"When the language relaxed and ceiling thresholds were removed, for example, there's this rebound effect where you see, in fact, the amount being prescribed kind of stabilizes or inflects upwards," Panagiotoglou said.
The study concludes that its findings show how practice standards can modify physician behaviour, but also highlight "how misinterpretation can harm patients."
Panagiotoglou said the findings underscore the potential for "unintended consequences" of sweeping changes to practice standards.
Physicians must be careful prescribing opioids, she said, especially given the underlying context of the toxic drug crisis that has claimed more than 16,000 lives in B.C. since the health emergency was declared in 2016.
But Panagiotoglou said it's important to include a diversity of voices at the decision-making table, such as patient-care advocacy groups.
The College of Physicians and Surgeons of B.C. said in an email it could not comment on the study because it was not directly involved in the research.
But it said the 2016 practice standard was informed by the "best available guidance at the time," and it has since been "revised substantially."
"In the 2016 practice standard, (the college) was explicit in acknowledging and endorsing the use of aggressive pharmacotherapy in the context of active cancer, palliative, and end-of-life care," it said in the statement.
B.C. Coroners Service data show there were 997 deaths due to unregulated drugs in the province in 2016, rising to 1,563 in 2018, and 2,271 last year.
Picture Courtesy: THE CANADIAN PRESS/Graeme Roy
