PainRelief.com Interview with:
Li Wang, PhD
Associate professor
Department of Anesthesia
Michael G. DeGroote Institute of Pain Research and Care
McMaster University
Ontario, Canada

PainRelief.com: What is the background for this study? What are the main findings?

Response: Chronic pain affects one in five people globally and is commonly treated with opioids. Unfortunately, opioid use may lead to serious harms including fatal and nonfatal overdose. Identifying predictors of opioid overdose may improve the shared decision-making for clinicians and patients when considering a trial of opioids for chronic pain. Although there have been previous reviews looking at predictors of opioid overdose following prescription for chronic pain, they have important limitations.

Our systematic review included 28 studies and 23,963,716 patients prescribed opioids for chronic pain that reported the associations of 103 predictors with opioid overdose. The baseline risk of non-fatal overdose was 1 in 500, and the risk of fatal overdose was 1 in 1000.

We identified 10 predictors, supported by moderate-to-high certainty evidence, that increased the risk of opioid overdose by 2-fold or more, including prescription of high-dose opioids (≥90mg morphine equivalent/day), fentanyl prescription, multiple opioid prescribers, use of multiple pharmacies, history of overdose, current substance use disorder, depression, bipolar disorder, other mental illness, or pancreatitis. The absolute risks of development of opioid overdose in patients with the predictor range from 4-12 per 1000 for non-fatal overdose and 2-6 per 1000 for fatal overdose, respectively.