David G Schwartz, PhD, and Stephen Lankenau, PhD, on Opioid Overdose Reversal in the Community Setting

The results of a recent study found that equipping members of the community with naloxone and a smartphone application to signal suspected opioid overdose could help to increase the likelihood of overdose reversal and lead to fewer opioid-related deaths.

For their study, the researchers examined data from an observational cohort given the smartphone app UnityPhilly from March 2019 to February 2020. The application alerted both 911 services and community volunteers with access to naloxone in the event of a suspected opioid overdose.

Overall, 291 suspected overdoses were reported, 202 of which were true overdoses. In 74 of the 202 cases, laypersons initiated naloxone use, resulting in successful reversal of overdose in 71 cases. Intervention in this way was shown to occur 5 or more minutes sooner than EMS services and resulted in recovery without transportation to the hospital in 39 of the cases.

Consultant360 reached out to study authors David G Schwartz, PhD, a professor of information systems at the Graduate School of Business Administration at Bar-Ilan University in Ramat-Gan, Israel, and Stephen Lankenau, PhD, from the Dornsife School of Public Health, Drexel University in Philadelphia, PA, for more information.

Consultant360: In your study, you found that successful reversal of opioid overdose was achieved in 95.9% of cases in which naloxone was administered by a layperson alerted by the smartphone app. Was this success rate surprising to you?

David G Schwartz, PhD and Stephen Lankenau, PhD: The effectiveness of naloxone to reverse the effects of opioid overdose is well-established, so we know that it works. But getting it there in time is a key challenge, particularly in areas of high incidence where EMS resources are strained. We expected that trained laypersons would have significant success in reversals but were indeed surprised that the rate was so high. The fact that our study focused on a neighborhood and population where drug use, overdose, and naloxone awareness is pervasive may have helped push the success rate up. That's one reason why a broader study will be important.

C360: Of the 291 signaled suspected overdoses, 89 were false alarms. What factors do you think contribute to such a high rate of false alarms, and would these false alarms be problematic after wider implementation of alert systems such as this one?

DGS: Actually, a 30.5% false alarm rate is surprisingly low. Consider that police dispatch systems are burdened with upwards of 90% in false alarms and up to 75% of ambulance dispatch calls are not a true emergency.2 Also, our study included alerts as false when cancelled by the signaler within 2 minutes. This does not necessarily mean that an overdose did not occur, but in some cases indicated that the caller felt they had the situation under control.

SL: Factors that contributed to false alarms during the study included the app/technology being new to study participants and them wanting to “try it out,” and general error of inadvertently signaling an alert (similar to errors when using other apps or when making phone calls). In a wider implementation study, we could focus app trainings on the issue of false alarms to decrease the number of them.

C360: You reported that in instances when laypersons administered naloxone, their intervention preceded the arrival of EMS by at least 5 minutes in 59.5% of cases. How significant do you think this time difference is in terms of successful reversal of overdose and patient outcomes?

DGS and SL: Every minute counts. Opioid overdose causes respiratory depression that may deteriorate into apnea, leading to anoxic injury. Models have suggested that each minute of cerebral ischemia is associated with the loss of millions of neurons, billions of synapses, and miles of myelinated fibers. The faster we can get naloxone to an overdose victim, whether through a community response app like ours, or strategically placed supplies of naloxone, the better.

C360: How could your findings impact current clinical practice?

DGS and SL: There are two main impacts on clinical practice going forward. State and municipal public health authorities can use our findings to inform the creation of high-impact community response programs leading to an immediate positive impact in similar urban environments. It is important to scale up our existing UnityPhilly model in Philadelphia and then throughout every region where responding to opioid overdose is a clinical challenge. The second is to implement tighter integration with EMS through modified EMS response protocols, what we call the mediated model of layperson dispatch. EMS can extend its effective reach and improve overdose reversal outcomes by encouraging and supporting such apps at the community level.


  1. Schwartz DG, Ataiants J, Roth A, et al. Layperson reversal of opioid overdose supported by smartphone alert: A prospective observational cohort study. Published online August 3, 2020. Lancet. doi: 10.1016/j.eclinm.2020.100474
  2. Blackstone EA, Buck AJ, Hakim S. The economics of emergency response. Published online November 15, 2007. Policy Sci. 2020;40:313–334. https://doi.org/10.1007/s11077-007-9047-6