Development of a Definition to Identify Severe Opioid Overdoses Treated in Emergency Departments, 2019-2022

Existing surveillance systems monitor nonfatal and fatal opioid overdoses but do not monitor severe nonfatal overdoses that require intensive medical interventions.

The Centers for Disease Control and Prevention's Drug Overdose Surveillance and Epidemiology system was used to query emergency department data from local syndromic systems and the National Syndromic Surveillance Program from January 2019 to August 2022. Opioid overdoses were classified as not severe or severe using a definition from the patient's chief complaint terms and discharge diagnosis codes. The percentage of opioid overdoses treated in emergency departments classified as severe was described by patient demographics, US Census region, and month.

Among 503 156 opioid overdoses in 29 states and Washington, DC, from January 2019 to August 2022, 17.4% were classified as severe. Common key terms found among severe opioid overdoses were hypoxia (34.8%), unresponsive (32.9%), and naloxone/Narcan (20.9%). The largest severity percentage was in the South Census region (19.6%). The trends of severe opioid overdoses remained stable during the study period.

Based on the severe opioid overdose definition, there was minimal change in the severity of opioid overdoses during the study period. This definition can help monitor trends of severe opioid overdoses, guiding public health action such as focusing on naloxone and fentanyl test strip distribution to areas of need.