Peer-to-peer emergency care

Every year, approximately 900 Stockholmers suffer a cardiac arrest in the midst of their everyday lives. Only 90 survive. The most important factors for survival are to immediately commence cardiopulmonary resuscitation (CPR) and to minimize the time to treatment with a defibrillator. The chances of survival decline by a full 10 percent for each minute without treatment.

In 2010, SMS-Lifesavers, a globally unique research project, was initiated at Karolinska Institute, which examines whether survival in the event of cardiac arrest can increase by using mobile technology.

“How can modern mobile technology be used to increase survival in the event of cardiac arrest outside a hospital?”

The emergency call goes out

When an emergency call about a suspected cardiac arrest is received by 112 (i.e. 911), an SMS is sent to enlisted SMS-Lifesavers in the vicinity. These lifesavers are trained in cardiopulmonary resuscitation and more than 13,000 volunteers currently participate in the project.

In June 2015, the service was upgraded to be app based in order to provide better assistance and support to the lifesavers. It is also linked to the defibrillator register, a national register of available defibrillators outside hospitals in Sweden. If a defibrillator is used within the first few minutes, seven out of ten could survive.

The service was designed in close collaboration with the Karolinska research team.

This is how we worked

It was important to ensure that users’ requirements were met in terms of design and development of the lifesaving app and for ensuring that content, functions and the graphic design supported the needs before, during and after an emergency call. The major challenge was in creating an intuitive service that was able to provide clear, relevant information to the lifesavers in order to access the location of the suspected cardiac arrest in an extremely stressful situation.

Interviews with SMS-Lifesavers

To fully understand the needs, attitudes and challenges that the lifesavers face we conducted semi-structured in-depth interviews with existing SMS-Lifesavers, including those who had responded to emergency calls and those who had not.

Mapping the customer journey

The insights from the interviews enabled us to document the process itself as a customer journey. It visually shows the key events that are linked to the SMS-Lifesavers process – before, during and after an emergency call. In addition to the contents of the app, we also identified a number of channel-independent insights concerning communication, feedback and follow-ups.

Design process

The major challenge in the design was to create a service that clarifies the user’s assignment and give clear instructions on where to go and what to do. Everything is on a small screen with limited space, while the user is under extreme stress. It is crucial that the user is able to reach the location of the emergency as soon as possible so there is no room for misunderstanding or obscurity.

From sketches to prototype

One of the starting points in the design process was to rapidly arrive at a solution that could be interacted with. After rough sketches on paper of the central flows in the app, the design work continued directly in a prototype. The prototype functioned as a starting point in discussions with clients and technology partners but also as a tool to involve users early on in the conceptual stage.

Together with users

The user-centered perspective also continued during the design phase and the prototype functioned as a platform for field tests and co-creation sessions with end users. The user interactions resulted in insights about what had to be clarified and improved, which in turn resulted in new versions of the service, on which we were able to perform further tests.

Design principles

  • Remove instead of add

    Identifying the information that was vital and information that was superfluous was an important part of the design process. Both communication and function were brought down to a minimum.

  • Right pace

    In the event of an emergency call, the user has to handle a great deal of information: the task to be performed, the location of the cardiac arrest and the nearest location of a defibrillator. Finding the right pace for the information flow was therefore necessary and we evaluated several different principles.

  • Simple framework

    Just as communication and functionality are to be clean and streamlined in the app, the visual framework must also be as simple as possible so as not to interfere with the primary information. Unnecessary details were removed and attention was paid to ensure that the remaining components would be as clear as possible.

  • Testing in the right environment

    To gain understanding for how the service functioned in the correct context, several tests were performed with end users in the city. Test emergency calls were made to the test participants, who tried to solve the various tasks using the app. After the tests, we interviewed the participants to identify areas of improvements.

  • Co-development x 2

    We designed the service together with the client to ensure that the solution supported the research project, as well as the client’s technology partner to ensure that the solution was practically feasible.

Functionality that make a difference

SMS-Lifesaver ID

From the initial interviews with users, we knew that there was a need to identify yourself at the location of the cardiac arrest, to relatives and also to ambulance personnel. The solution was a special ID that can be shown when needed.


The map is the main view of an emergency location. It is simple, clean and focuses completely on the most important information.

Test emergency calls

The view of the emergency is the most critical view in the app, but also the view the users see most seldom (only when a cardiac arrest occurs in the vicinity). There is also a need to feel well prepared. Accordingly, we developed a function that makes it possible to simulate an emergency call and therefore test the app to enable lifesavers to prepare themselves ahead of an emergency call.

Click on the image to enhance.

SMS-Lifesaver ID
Test emergency calls

In the media

SVT News

The project has received a great deal of attention in the media, including on SVT (the Swedish Public Service TV broadcaster): The new app saves lives in the event of a cardiac arrest and SMS-Lifesavers increase the chances of survival.

New England Journal of Medicine

The research report has been published in the New England Journal of Medicine and can be read here.