Author + information
- Anthony N. DeMaria, MD, MACC, Editor-in-Chief, Journal of the American College of Cardiology⁎ ()
- ↵⁎Address for correspondence to:
Dr. Anthony N. DeMaria, Editor-in-Chief, Journal of the American College of Cardiology, 3655 Nobel Drive, Suite 630, San Diego, California 92112
The patient assured me that, although he had never experienced any symptoms, he was sure that there was something wrong with his heart. When I inquired how he could be certain, he informed me that he had been recording his heart rate and rhythm automatically for some time on a smartphone application. Recently, for the first time, he recorded a heart rate that fluctuated between 130 to 150 beats/min and persisted for almost 1 hour before returning to his usual rate of 60 beats/min. This was accompanied by an increase in his smartphone app quantified stress level, but was unrelated to his sleep pattern, exercise level, or dietary and caloric intake that he also monitored and recorded daily. And so was the concept of self quantification of health and fitness injected into my medical practice.
My introduction to the concept of self quantification came from Chris Anderson, the editor of Wired® magazine, during a JACC Editorial Board retreat. He pointed out that the development of small physiological sensors had made it possible for almost anyone to monitor a variety of their own health and fitness parameters. My impression was that Chris represented a very small group in the San Francisco Bay area with an extreme interest in their own wellness who did such monitoring. In fact, the majority of questions that he received from the Board related to why he did this and what he did with the data. Although a movement called “Quantified Self” did indeed begin in San Francisco, it has now spread throughout the United States through a spectrum of blogs, local meetings, and large conferences, and attracted considerable attention. An article in the Economist (1) describes Quantified Self as (my translation) an eclectic mix of early adopters, fitness zealots, technology enthusiasts, personal-development devotees, and patients sharing a belief that self-tracking, or gathering and analyzing data about their everyday activities, can help them improve their lives.
The number of physiological parameters that can currently be self-monitored by individuals is extensive and rapidly increasing. Miniaturization and cost reduction of sensors, such as accelerometers and altimeters, have made it easily possible to track patterns of exertion, rest, and sleep. Devices to record heart rate variability and skin conduction can provide indirect evidence of the level of stress. The Zeo® is a headband that records and analyzes brainwaves to determine the duration and level (e.g., rapid eye movement) of sleep. A sensor exists that can be attached to an inhaler used by asthmatics to determine the influence of environment on their condition. Highly motivated individuals can have their DNA sequenced for disease risk by services such as 23andMe, and can obtain blood and stool analysis performed by services such as Your Future Health. Moreover devices used for these purposes can be easily incorporated into Smartphones or bracelets, and can be readily interfaced to computers and the Internet. Accordingly, people can not only track their own characteristics, but also enter them into a database to compare them to others who are using the same technology. The implications of such databases for individuals as well as medicine in general are obvious.
The number of people who are engaged in extensive self tracking at this time is uncertain, but likely to be relatively small. In addition, thus far, the technology for such self quantification has been developed and provided by small start-up companies. However, the interest of individuals in monitoring their own health is increasing and capturing the attention of even large biomedical and digital instrument companies. It seems certain that more technology will be appearing in the future, will be easily interfaced to widely utilized devices such as Smart phones and home appliances, will render individual and group data more readily available, and will be increasingly utilized by a broader segment of the population.
From my perspective, it is not clear where this movement to self quantification will ultimately lead. In a general sense, all of us currently self-track certain parameters such as weight, hours of sleep, and magnitude of exercise. Self quantification involves not only much more detailed and in-depth cataloguing, but also tracking parameters that have not been followed in the past such as levels of sleep and blood markers of inflammation. It seems intuitive that the more data a person has about themselves the better they will be able to optimize their health. Awareness of lifestyle choices and the potential detrimental effect they can have will likely incentivize healthy behavior. Presumably individuals will be able to identify adverse factors and take or seek corrective action prior to the appearance of signs or symptoms of disease. However, it is uncertain how willing the general public will be to perform and archive detailed self monitoring. It is not clear that the public will be able to fully interpret and appropriately act on some of the data that they seek, nor is it certain that false-positive findings will be rare. On occasion, self tracking may lead to a false sense of security in the face of abnormalities. There is obviously a cost involved in self quantification, and the effectiveness of such expenditures needs to be determined. One thing seems obvious—the trend to extensive self monitoring by progressively larger segments of society would yield databases that could be of great value to the medical community in understanding the prevention, diagnosis, and treatment of diseases.
Obviously, not many patients similar to the one I described above are apt to be seen in our current practices. However, it is a universal experience that patients have more access to healthcare information, are increasingly knowledgeable about disease entities and therapeutic options, and frequently have pointed and specific questions about their condition. Self quantification may be seen as an extension of this increasing interest and involvement on the part of the public in their own health. Given this interest, and the rapidly emerging technology to enable individuals to identify and monitor their own personal risk and physiology, we can anticipate this trend to continue. In fact, it has the potential to reshape the practice of medicine in a major way. Leroy Hood, a much honored physician-investigator and one of the inventors of the first automated DNA sequencers, has advocated self-monitoring technology for a future era of medicine he refers to as P4: predictive, preventive, personal, and participatory. In my view, such an orientation for the practice of medicine would be very beneficial. It would require, of course, that we adjust to this orientation; those who did so would almost certainly enjoy the greatest success. In the meantime I am beginning to do some limited self monitoring myself, and increasingly advocating it for my patients.
- American College of Cardiology Foundation
- ↵The Economist, Technology Quarterly, The Quantified Self: Counting every moment: Technology and health: Measuring your everyday activities can help improve your quality of life, according to aficionados of “self-tracking.”. March 3, 2012.