With rates of prescription drug overdose at an all-time high, researchers at Columbia University’s Mailman School of Public Health found that among individuals who visited the emergency department, the risk of subsequently dying from prescription drug overdose increased markedly based on how many times they visited the ER. Relative to patients with one or fewer trips to the ER in the previous year, the risk of dying from prescription drug overdose was five times the rate for those with two visits, 17 times for those with three visits, and 48 times for those with four or more visits.

[Photo: Dr. Joanne E. Brady]

Despite the importance of the ER as a key clinical entry point for patients at high-risk of prescription drug overdose, the new study is among the first to evaluate the relationship between the ER and overdose. Results are published online in the journal Annals of Epidemiology.

“While ‘doctor-shopping’— the practice of visiting multiple health care providers to obtain controlled substances— has been shown to be associated with prescription drug overdose in many studies, our investigation demonstrates that the frequency of emergency department visits in the past year is a strong predictor of subsequent death from prescription drug overdose,” said Dr. Joanne E. Brady, adjunct assistant professor of epidemiology at the Mailman School of Public Health and first author.

Nearly 60 percent of drug overdose deaths involve prescription drugs.  According to 2011 data, 1.4 million ER visits implicated use of a prescription drug in a manner other than for which it was prescribed.