MedicalResearch: What are the main findings of the study?
Dr. King: Unintentional overdoses from prescription opioid painkillers have been rising sharply in the US and Canada during the past two decades, killing thousands of people every year. A lot has been written about the subject in both popular media and scholarly literature, but we still don’t have a very good idea of why this has happened. So we tried to objectively and systematically assess evidence for what has contributed to increasing mortality. We found the following:
(1) The evidence base for why mortality has increased is very thin, and more research is urgently required.
(2) We found evidence for at least 17 different causes of increased mortality. We found the most evidence for the following factors: dramatically increased prescription and sales of opioids; increased use of strong, long-acting opioids like oxycodone and methadone; combined use of opioids and other (licit and illicit) drugs and alcohol; and social and demographic characteristics. We found little evidence that internet sales of pharmaceuticals and errors by doctors and patients–factors commonly cited in the media–have played a significant role.
MedicalResearch: Were any of the findings unexpected?
Dr. King: On the whole, we were surprised by how few studies have actually investigated the causes of increased mortality in a rigorous manner. We were also surprised to find little solid evidence for several factors that have received substantial coverage in media and in commentaries/editorials, namely: errors by physicians and patients; internet sales of opioids; and so-called “pill mills.”
MedicalResearch: What should clinicians and patients take away from your report?
Dr. King: Clinicians, patients, and policymakers should take away the following messages:
(1) Increased mortality is driven by many different factors, including the prescribing behavior of physicians, particularly the prescription of opioid analgesics for chronic non-cancer pain, and the prescription of stronger, long-acting opioids; patients’ and other users’ behaviors, including use of opioids in conjunction with alcohol, sedatives, and anti-depressants; and systemic factors such as the liberalizing of opioid prescribing guidelines.
(2) There is likely no one-size-fits-all strategy for reducing mortality in the US and Canada, which will require novel, multisectoral public health approaches that address multiple determinants and are targeted at specific populations.
(3) This should also sound a cautionary note for global efforts to increase access to opioids. Currently, the US and Canada rank #1 and #2 in per capita opioid consumption, and in many poor countries prescription opioids are unavailable. Since lack of access to opioids is considered to be a violation of a basic human right to freedom from unnecessary pain, many are pushing for increased opioid access in low in come countries. Our findings show some of the possible ways that this could lead to increased deaths, and thus might be useful in preventing other countries from following the same path as the US and Canada.
MedicalResearch: What recommendations do you have for future research as a result of this study?
Dr. King: One of our principal findings is that there is a serious lack of solid, well-designed research that is intended to identify the causes of increased opioid-related mortality, and almost none explaining the sociodemographic differences in opioid-related mortality.
Recommendation #1 is for well-designed research explicitly designed to identify causes of mortality increases on national, state/province, and local levels.
Recommendation #2 is for research designed to identify causes of variations in opioid-related mortality according to race/ethnicity, age, gender, socioeconomic status, and urban/rural residence.
Finally, recommendation #3 is for research that tries to investigate how to prevent similar increases in opioid-related mortality as access to opioids is increased in other countries.