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About 3% of patients who were not taking opioid painkillers before major surgery continue to use them for more than 90 days after their operation


About three per cent of patients who were not taking opioids, which include strong painkillers like morphine and oxycodone, before major surgery continue to use the potent painkillers for more than three months after surgery, according to a new study by researchers at the Institute for Clinical Evaluative Sciences (ICES), Toronto General Hospital, University Health Network and St. Michael’s Hospital.

While for any individual patient, this 3.1 per cent risk is relatively low, given the millions of major surgical procedures performed worldwide every year, the 3.1 per cent does represent a large absolute number of patients who continue to use opioids for more than three months after surgery.

“This is definitely worrying from a public health standpoint given the millions of patients that undergo surgery on an annual basis,” said Dr. Hance Clarke, author, assistant professor of Anesthesia at the Toronto General Hospital and University of Toronto, and the Medical Director of the Toronto General Hospital Pain Research Unit.

The study, published today in the BMJ, identified several features that were associated with prolonged opioid use.

“Patients who were younger, had a lower household income, had an operation performed on the chest, or had previous use of anti-depressant or anti-anxiety medications were more likely to continue using opioids,” added Clarke.

The population-based retrospective cohort study looked at 39,140 previously opioid-naïve patients aged 66 years or older undergoing major elective surgery in Ontario between April 2003 and March 2010.

“With the growing concern of an addiction crisis resulting from physician prescription medications, major surgery remains a very common healthcare scenario where some degree of opioid exposure is largely unavoidable. Our study provides important reassurance to both perioperative physicians and patients regarding the potential risks of opioid exposure following major surgery,” adds Clarke.

The authors add that research is urgently needed to better determine why people continue to use opioids for long periods of time after surgery. Without such information, appropriate methods to decrease the current existing risk cannot be developed.

The study “Rates and risk factors for prolonged opioid use after major surgery: population based cohort study,” was published today in the BMJ.

Authors: Hance Clarke, Neilesh Soneji, Dennis T. Ko, Yun Lingsong and Duminda N. Wijeysundera.

ICES is an independent, non-profit organization that uses population-based health information to produce knowledge on a broad range of healthcare issues. Our unbiased evidence provides measures of health system performance, a clearer understanding of the shifting healthcare needs of Ontarians, and a stimulus for discussion of practical solutions to optimize scarce resources. ICES knowledge is highly regarded in Canada and abroad, and is widely used by government, hospitals, planners, and practitioners to make decisions about care delivery and to develop policy.

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  • Deborah Creatura
  • Communications, ICES
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