Featured Research

Behind the research: how often do patients fill opioid prescriptions in Canada, the US and Sweden? The answer may surprise you

Pharmacy

A new study published today in JAMA Network Open found that patients in Canada and the U.S. who underwent one of four common surgical procedures filled opioid prescriptions within a week after discharge at a rate that was nearly seven times higher than patients in Sweden.

The study – which focused on adults who underwent gallbladder removal, appendix removal, meniscus repair and breast lump removal – is the first of its kind to systematically evaluate the differences in the use of opioids after surgery for patients receiving similar procedures in different countries.

About 76 per cent of the U.S. patients and nearly 79 per cent of the Canadian patients filled a prescription for opioids after their surgery, versus just 11 per cent of Swedish patients.

Dr. Hannah Wunsch is a staff physician in the department of critical care medicine at Sunnybrook and a co-author of the study. Below, we asked her more about how the study came together, which findings most surprised her, and what we can learn from Swedish prescribing practices.

How did you become interested in studying opioid prescription rates?

As a pharmaco-epidemiologist, I’m always interested in the question of, “what medications are people getting?”

The majority of my work has focused on critically ill patients. Years ago, it became clear that there was an opioid epidemic happening, but at the time the focus was very much on the community and elicit use of opioids. I noted that, although we use opioids every day in clinical practice in both surgery and critical care, no one was talking about or looking at prescribing practices in those settings, and how it might impact patients and the wider communities. That has, of course, now changed as many studies have come out looking at the question of prescribing practices.

Why did you choose to compare Canada to the US and Sweden? 

We knew we wanted to compare prescribing practices in Canada and the US to see how similar or different they looked. We also knew we wanted to look at some other country in Europe, as we hypothesized that prescribing practices would look very different. We did spend some time trying to identify a country which we knew would have pretty comprehensive data on prescribing for everyone in the country, and also have data that would be readily accessible. So, we identified a few potential options we explored, but it was a little bit of serendipity that we were introduced to our Swedish colleagues, and they were able to access the data for this project.

How did you decide to study those four low-risk surgeries in particular?

We spent a lot of time thinking about procedures. We wanted them to be common, so that we would have a lot of patients in each country, not frequently done in conjunction with other procedures or be associated with other medical conditions (such as cancer) that might make it hard to determine what prescriptions were due to the surgery versus other concerns. We also wanted them to be procedures that did not involve a prolonged hospital stay, so that we wouldn’t have the problem of what people received over days and days in the hospital.

Were you surprised by any of the findings?

We were surprised by a number of the findings. First, we were surprised at how similar Canada and the US were in terms of prescribing practices. I think there is still the perception that because the US has the “bigger” opioid problem in terms of overdoses and deaths, that the filling of prescriptions after surgery would be more frequent than in Canada.

The second big surprise was the magnitude of the difference in Sweden. To some degree, this was a study of demonstrating what people thought they already knew, namely that opioid use is much lower in many European countries after surgery. However, no data really demonstrated that for sure, and we certainly didn’t know just how different it would be: a 7-fold difference in rates of prescriptions filled.

The study mentions that some prescribers (incorrectly) view tramadol and codeine as “safer” opioid alternatives. How did that become such a prevalent view, and what could be done to change it? 

Both drugs are relatively low potency, meaning that an individual pill generally contains “less” opioid than some other opioids we prescribe. For that reason, many people view them as “weak”. However, both drugs rely on metabolism to generate active metabolites, which can be variable between people, making it hard to predict an individual’s response to either of these drugs. The use of the term “weak opioid” is also a concern, as the adjective lulls people into assuming it’s safer. One way to try to improve education is to move away from the terms “strong” and “weak” to describe opioids to remove that sense of security.

Tramadol is not a controlled substance in Canada, which likely makes it feel safer to people, and makes it easier to prescribe. On the other hand, it is not covered by the prescription drug plan in Ontario, so individuals have to pay for it themselves if it is prescribed. Undoubtedly, this variability in scheduling and coverage influences the prescribing patterns we see when comparing the different countries.

The study found that patients in Canada and the US filled opioid prescriptions within the first seven days after discharge at a rate nearly 7-fold higher than individuals in Sweden. What are Swedish prescribers doing differently? Is there anything we can learn from them?

This study leaves a lot of unanswered questions. For example, we don’t know what individuals in Sweden are told when they are discharged, or what degree of pain they experience, or whether they were satisfied with their care and their pain control. However, we have no reason to think these aspects of surgical care are inadequate in the Swedish system. So, I think the main thing we can learn is that there is the potential to do things differently and to consider whether at least some of our patients are receiving unnecessary prescriptions.

I think it is helpful to see a model of care that is so different, as it is proof that alternative approaches are potentially viable options. A fantastic opinion piece was published in the New York Times in January, 2018 that describes the experience of an American receiving surgery in Germany, and the different approach to post-operative opioid prescribing that she experienced. I view that piece as the anecdote that confirms our results.

About the author

Sybil Millar

Sybil Millar

Sybil Millar is the Communications Advisor for the Ross Tilley Burn Centre, Critical Care and Infectious Diseases programs at Sunnybrook.

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