May 11 2015

Frequent Trips to ER Are Powerful Predictor of Death from Prescription Drug Overdoses

Four or More ER Visits in Past Year Linked With 48 Times Greater Risk of Death from Rx Drug Overdose

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.

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 Joanne E. Brady, PhD, 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 prescription drugs in a manner other than for which it was prescribed.

The researchers analyzed data for the years 2006–2010 from the New York Statewide Planning and Research Cooperative System, a data reporting system that collects emergency department visit data from non-federal hospitals in New York State, including patient characteristics, discharge diagnoses, and procedures received.  These records were matched with mortality data for patients who subsequently died.

By comparing 2,732 patients who subsequently died from prescription drug overdose and 2,732 patients who did not, the researchers found substantially increased risk in patients who were diagnosed with substance use disorders or other psychiatric disorders, and who were male, 35-54 years of age, or white. Additionally, patients who subsequently died of a prescription drug overdose were more likely to be discharged against medical advice at the initial emergency room visit.

“Emergency department visits may serve as an important window of opportunity for identifying patients at heightened risk of prescription drug overdose and for implementing evidence-based intervention programs, such as providing these patients and their families with take-home naloxone and drug treatment referral,” said senior author Guohua Li, MD, DrPH, professor of Epidemiology at the Mailman School of Public Health and director, Center for Injury Epidemiology and Prevention at Columbia.

Co-authors are Drs. Charles DiMaggio, Katherine Keyes, and John J. Doyle of Columbia, and Dr. Lynne Richardson of Mount Sinai School of Medicine.

The study was supported in part by the National Center for Injury Prevention and Control of the Centers for Disease Control and Prevention (Grant 1 R49 CE002096) and the National Institutes of Health (NIAAA: K01 AA021511).

About Columbia University’s Mailman School of Public Health

Founded in 1922, Columbia University’s Mailman School of Public Health pursues an agenda of research, education, and service to address the critical and complex public health issues affecting New Yorkers, the nation and the world. The Mailman School is the third largest recipient of NIH grants among schools of public health. Its over 450 multi-disciplinary faculty members work in more than 100 countries around the world, addressing such issues as preventing infectious and chronic diseases, environmental health, maternal and child health, health policy, climate change & health, and public health preparedness. It is a leader in public health education with over 1,300 graduate students from more than 40 nations pursuing a variety of master’s and doctoral degree programs. The Mailman School is also home to numerous world-renowned research centers including ICAP (formerly the International Center for AIDS Care and Treatment Programs) and the Center for Infection and Immunity. For more information, please visit