Abstract
Precision prevention refers to the use of data-intensive technologies to detect early indicators of disease and risk factors at the individual level. Precision prevention is not just a policy vision for a distant future but a development currently gaining momentum through wearables and self-tests marketed directly to consumers. We critically analyze one of the applications already on the market, namely detection of asymptomatic atrial fibrillation via smartwatches. We examine the promises made by manufacturers of smartwatches in relation to perspectives of general practitioners (GPs) in Denmark, who experience that new opportunities for disease prevention often come with new challenges. As one informant termed it, heart rate notifications are a form of "unauthorized screening" with uncertain benefits for individual patients and the healthcare system. The case of device-detected asymptomatic atrial fibrillation illustrates how precision prevention, via wellness technologies, can lead to a temporal disruption of evidence. We use this term to highlight the concern that evidence becomes the result of implementation, rather than the basis for it, thus turning consumers into experimental research subjects. The case of heart rate notifications also illustrates how the proactive approach to disease prevention, promoted by the wellness technology industry, drives a need for reactive research evaluating the benefits and harms of detection after the fact. We call for more attention to how big tech expansionism impacts the organization of health care and health research, as well as how the wellness technology industry shapes our understanding of disease and health.