The Use of Mobile Phones in Out of Hospital Cardiac Arrest to Increase Bystander CPR (RUMBA)

Karolinska Institute logo

Karolinska Institute




Ventricular Fibrillation
Heart Diseases
Out-of-Hospital Cardiac Arrest
Death, Sudden, Cardiac


Other: MLS dispatch for bystander CPR

Study type


Funder types




Details and patient eligibility


Death from cardiac disease is one of the most common causes of death in the western world. The majority of these deaths takes place outside hospital as sudden cardiac death. However, with immediate (within minutes) actions such as cardiopulmonary resuscitation (CPR) and defibrillation many lives would be saved. CPR is a key factor to increase survival from Out of Hospital Cardiac Arrest (OHCA). CPR buys time by supporting the brain with some circulation in waiting for a defibrillator that can restart the heart. In Sweden about 2,5 million people are trained in CPR. However, only about half of all OHCA victims will get CPR in waiting for ambulance arrival. The aims of the Response to Urgent Mobile message for Bystander Activation (RUMBA) trial is to try a new way of logistics to increase bystander CPR by recruiting lay volunteers to nearby OHCAs via their mobile phones. Hypothesis: By dispatching lay volunteers to nearby OHCAs with mobile phone technology bystander CPR may increase from 50% to 62,5 %

Full description

Survival from out-of-hospital cardiac arrest (OHCA) is generally low, about 5-10%, with the exception of a few controlled settings (casinos, airports and some cities). The poor prognosis of OHCA is mainly explained by long time intervals between cardiac arrest, cardiopulmonary resuscitation (CPR) and defibrillation. To increase bystander actions and to decrease time to defibrillation substantial resources have been put into CPR educational campaigns and in recent years into the spread of automated external defibrillators (AEDs) in public venues. Still, the vast majority of the public with CPR training will never use their skills in real life. Mobile phone technology offers the possibility to locate single mobile phone users at any given moment. If designated lay responders immediately can be identified and recruited to the scene of nearby suspected OHCAs bystander CPR, CPR quality and finally survival might be increased. Mobile phone positioning and dispatching of lay responders: Tailored mobile phone services that use MPS to locate selected mobile phone users can be developed for different purposes. A computer-based application for mobile phone positioning and dispatch of lay responders is developed for the purpose of this study and is referred to as the Mobile Lifesaver Service (MLS). All participants connected to the MLS are called Mobile Responders (MRs). The MLS acts as an interface between the emergency medical service (EMS) data system and the MPS. The MLS handles the localisation and dispatching of MRs based on the data present in the EMS data system. The location of all incoming calls to all dispatch centres in Sweden is determined automatically. When the dispatcher receives an emergency call from a witness of a suspected OHCA the dispatcher activates the MLS in parallel with standard EMS. When the MLS is activated it uses the MPS to compare the current geographical position of all MRs connected to the MLS with the position of the incoming emergency call of the suspected cardiac arrest. If one or more MRs is present within a radius of 500 m (optional) from the suspected arrest the MRs receives a cardiac arrest alert with a computer generated phone call and a text message (i.e. SMS = short message system) with information about the place of the suspected cardiac arrest. A map for finding the way to the suspected OHCA is also sent. Additional information can, if needed, be sent to the MRs. For further details see "Mobile phone technology identifies and recruits trained citizens to perform CPR on out-of-hospital cardiac arrest victims prior to ambulance arrival." Ringh M, Fredman D, Nordberg P, Stark T, Hollenberg J. Resuscitation. 2011 Dec;82(12):1514-8. Data from earlier non randomized pilot studies in urban Stockholm has shown that CPR was performed by MLS dispatched lifesavers prior to ambulance, firefighters and police in about 20 % of all cases of true OHCAs. The hypothesis is that bystander CPR in Stockholm County can be increased from 50 % to 62,5% if the MLS is used. An estimated number of 6000 MR needed is based on earlier pilot studies. The current proportion of bystander CPR is derived from OHCA registry data but is uncertain. A safety and efficacy analyze will be made at approximately 200 true OHCA cases. A ethical and safety board and log for adverse events will be set up.


600 patients




8+ years old


No Healthy Volunteers

Inclusion criteria

  • All suspected OHCAs in Stockholm County
  • All EMS treated out of hospital cardiac arrest in Stockholm County were the mobile positioning system is triggered

Exclusion criteria

  • Traumatic OHCA
  • Children under 8 years of age
  • Suicide
  • Intoxications
  • Obvious signs of death
  • Do not resuscitate orders (DNR)

Trial design

Primary purpose

Health Services Research



Interventional model

Single Group Assignment


Quadruple Blind

600 participants in 2 patient groups

MLS dispatch for bystander CPR
Experimental group
When an alarm call of a suspected OHCA suspected is received by the EMS dispatch operator a Mobile positioning system (MPS) is activated. The MPS uses the mobile phone network to geographically locate all lay volunteers connected to a tailored mobile phone service called mobile life saver (MLS). The MPS then locates all lay volunteers within a pre defined radius from the suspected OHACA an alerts them with a computer generated voice call and an sms containing data about were about were the suspected OHCA is located. A map is also sent in order to make route finding easy.
Other: MLS dispatch for bystander CPR
NO MLS dispatch for bystander CPR
No Intervention group
No activation of mobile positioning system to locate and recruit lay responders to nearby OHCAs

Trial contacts and locations



Data sourced from

Clinical trials

Find clinical trialsTrials by location
© Copyright 2024 Veeva Systems