CANADIAN STUDY DISTORTS Rx-OPIOID-RELATED DEATHS
Repeated reports of increasing deaths associated with prescribed opioid analgesics should concern us all, but they may also portray a distorted picture of the scope and urgency of the problem. This is evident in a report on mortality trends in Canada, which serves as a lesson in why readers must be wary of how such data are presented in the literature and the press.
Canadian investigators supported by the Institute for Clinical Evaluative Sciences (ICES) and the Ontario Ministry of Health and Long Term Care reviewed opioid prescribing trends and all the deaths involving alcohol, drugs, or both in Ontario [Dhalla et al.] Their report,published in the Canadian Medical Association Journal (CMAJ) concluded that increases in opioid analgesic prescribing have directly contributed to an alarming rise in associated mortality, and they pay particular attention to concerns about oxycodone formulations. Sensational national news headlines proclaimed, "Canadian pain releiver deaths double", however, a close look at their data and their presentation suggests some alternative perspectives:
During the 14-year time period of the study there were a total of 7,099 deaths involving alcohol, drugs, or both; of those less than half (3,406 or 48%) implicated opioids in the cause of death. Fatalities associated with opioids increased from 13.7 deaths per million residents to 27.2 deaths per million. In perspective, however, while there indeed was nearly a doubling, the population incidence rate rose from merely 0.0014% to 0.003%, making such events a rare occurrence even at the higher extreme. (From another viewpoint; the lifetime odds of being struck by lightning, was calculated at more than 5-times greater or 0.016%)
Curiously, the 3,693 deaths (52%) involving alcohol (possibly also including nonopioid drugs) were not mentioned by the authors as being of concern. And, further complicating the picture, more than a third (38%) of opioid-associated deaths involved multiple drugs, including heroin (which confounds the focus on prescription opioids) and nonopioids (benzodiazepines, antidepressants, and/or alcohol).
Most of the victims (84%) had visited their physicians or the emergency room within 2 weeks prior to death, and analysis of the records revealed anxiety, depression, or drug dependence were commom diagnoses in addition to pain-related complaints. And, death was attributed to suicide in nearly a quarter of all cases (24%) involving opioids. So, while the availability of opioids was a factor, mental health problems may have been a more critical precipitating factor in a significant portion of all deaths. In some cases, the undertreatment of pain could have been a contributing factor in either suicide or in opioid over-use leading to unintentinal death; however, again the study does not address these vital issues of concern.
There is no indication in the study data of what proportion of decedents were patients for whom the opioids were prescribed, versus being diverted to other persons, and whether death associated with accidental misuse or intentional abuse. Such factors could make a significant difference in how the purported hazards of opioids are interpreted and portrayed.
Although the authors actually examined prescribing trends, they made no attempt to assess the probability risk of prescribed-opioid fatalities; for example, one way this could be calculated is the number of deaths divided by the total number of prescribed doses over the period time used for the study. It has been previously shown that such risks are extremely low in the U.S. and would likely be similar or even lower in Canada.
This is not to belittle legitimate concerns about the misuse or abuse of opioids and the tragedy of analgesic-related deaths. There is no question about opioids being strong medications that can be fatally toxic if improperly prescribed and/or used. However, data manipulations that exaggerate opioid problems can be a gross misrepresentation of reality, and it is important to recognize there is almost always more than one way to view, analyze, and present data as evidence depending on how one wants to slant the perspective. Mixed messages are confusing and, when combined with a "data-rich" study report that obscures rather than clarifies the problems at hand, can and do lead to misguided conclusions by the unwary reader and in the mass media.
Source: S.B. Levitt, Pain-Topics.