Socially disadvantaged Ontarians being prescribed opioids on an ongoing basis and at doses that far exceed Canadian guidelines

January 25, 2011 Toronto

A study performed at the Institute for Clinical Evaluative Sciences (ICES) has found that Canadian guidelines for opioid therapy are not being followed for many socially disadvantaged Ontarians. Opioids include strong painkillers like morphine, codeine and oxycodone.

“Our study found that patients covered by Ontario’s public drug plan were very often being prescribed opioids on a long-term basis, frequently at doses that far exceed the amounts set out by Canadian clinical guidelines. Furthermore, we found preliminary data indicating that patients who receive these high opioid doses die at a far greater rate than the general population,” says lead author Tara Gomes, an epidemiologist at ICES.

The study examined prescriptions paid by Ontario’s public drug plan for patients aged 15 to 64 during the 6-year period from 2003 to 2008 and found that:

  • Opioid prescribing rates rose 16.2 per cent over this period.
  • By 2008, 180,974 individuals were receiving nearly 1.5 million opioid prescriptions annually.
  • The use of sustained-release opioids such as OxyContin increased by 52 per cent over the study period.
  • In 2008, 32.6 per cent of people treated with OxyContin received daily doses equivalent to more than 200 mg of oral morphine per day.
  • Among patients receiving high daily doses of opioids (more than 200 mg morphine per day), all-cause mortality rates were up to 10 times higher than that of the general population.
  • Among patients prescribed opioids in 2004 exceeding Canadian guidelines, 19 per cent of all deaths during the subsequent two years were opioid-related. These deaths occurred at a median age of 46 years.

“This study tells a very discouraging story about the prescribing of opioids in Ontario,” says David Juurlink, a co-author on the study and ICES scientist. “These drugs are being prescribed to large numbers of people, often at doses that are not simply high, they are dangerous. Most patients, and even some doctors, may not appreciate that these drugs can cause death, particularly at high doses or when taken with alcohol or other sedating drugs, as they often are.”

The study “Trends in Opioid Use and Dosing in the Socioeconomically Disadvantaged,” is in the January 25, 2011 issue of Open Medicine.

ICES is an independent, non-profit organization that uses population-based health information to produce knowledge on a broad range of health care issues. Our unbiased evidence provides measures of health system performance, a clearer understanding of the shifting health care 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.