Objective No case definition exists that allows public health authorities to accurately identify opioid overdoses using emergency medical services (EMS) data. We developed and evaluated a case definition for suspected nonfatal opioid overdoses in EMS data. Methods To identify suspected opioid overdose–related EMS runs, in 2019 the Rhode Island Department of Health (RIDOH) developed a case definition using the primary impression, secondary impression, selection of naloxone in the dropdown field for medication given, indication of medication response in a dropdown field, and keyword search of the report narrative. We developed the case definition with input from EMS personnel and validated it using an iterative process of random medical record review. We used naloxone administration in consideration with other factors to avoid misclassification of opioid overdoses. Results In 2018, naloxone was administered during 2513 EMS runs in Rhode Island, of which 1501 met our case definition of a nonfatal opioid overdose. Based on a review of 400 randomly selected EMS runs in which naloxone was administered, the RIDOH case definition accurately identified 90.0% of opioid overdoses and accurately excluded 83.3% of non–opioid overdose–related EMS runs. Use of the case definition enabled analyses that identified key patterns in overdose locations, people who experienced repeat overdoses, and the creation of hotspot maps to inform outbreak detection and response. Practice Implications EMS data can be an effective tool for monitoring overdoses in real time and informing public health practice. To accurately identify opioid overdose–related EMS runs, the use of a comprehensive case definition is essential.

Objective: To help understand whether decreased emergency medical services (EMS) utilization due to the COVID-19 pandemic contributed to increased accidental fatal drug overdoses, we characterized recent EMS utilization history among people who had an accidental opioid-involved fatal drug overdose in Rhode Island. Methods: We identified accidental opioid-involved fatal drug overdoses among Rhode Island residents that occurred from January 1, 2018, through December 31, 2020. We linked decedents by name and date of birth to the Rhode Island EMS Information System to obtain EMS utilization history. Results: Among 763 people who had an accidental opioid-involved fatal overdose, 51% had any EMS run and 16% had any opioid overdose–related EMS run in the 2 years before death. Non-Hispanic White decedents were significantly more likely than decedents of other races and ethnicities to have any EMS run ( P < .001) and any opioid overdose–related EMS run ( P = .05) in the 2 years before death. Despite a 31% increase in fatal overdoses from 2019 through 2020, corresponding with the onset of the COVID-19 pandemic, EMS utilization in the prior 2 years, prior 180 days, or prior 90 days did not vary by time frame of death. Conclusion: In Rhode Island, decreased EMS utilization because of the COVID-19 pandemic was not a driving force behind the increase in overdose fatalities observed in 2020. However, with half of people who had an accidental opioid-involved fatal drug overdose having an EMS run in the 2 years before death, emergency care is a potential opportunity to link people to health care and social services.