Wear With Care: A Call for Empirical Investigations of Adverse Outcomes of Consumer Health Wearables

Abstract

Consumer health wearables—commercially available health tracking technologies such as smartwatches, fitness trackers, and wearable sensors coupled to smartphones—have provoked a paradigm shift in how people approach their health. One fifth of Americans use a wearable on a regular basis.1Bayoumy K. Gaber M. Elshafeey A. et al.Smart wearable devices in cardiovascular care: where we are and how to move forward.Nat Rev Cardiol. 2021; 18: 581-599Crossref PubMed Scopus (208) Google Scholar These technologies are recognized for their promises to lower costs and save lives,2Wearable technology promises to revolutionise health care. The Economist.https://www.economist.com/leaders/2022/05/05/wearable-technology-promises-to-revolutionise-health-careDate accessed: December 22, 2022Google Scholar and research documents their efficacy for addressing a range of health promotion and management concerns.1Bayoumy K. Gaber M. Elshafeey A. et al.Smart wearable devices in cardiovascular care: where we are and how to move forward.Nat Rev Cardiol. 2021; 18: 581-599Crossref PubMed Scopus (208) Google Scholar,3Mattison G. Canfell O. Forrester D. et al.The Influence of wearables on health care outcomes in chronic disease: systematic review.J Med Internet Res. 2022; 24e36690Crossref PubMed Scopus (11) Google Scholar,4Brandes A. Stavrakis S. Freedman B. et al.Consumer-led screening for atrial fibrillation: frontier review of the AF-SCREEN International Collaboration.Circulation. 2022; 146: 1461-1474Crossref PubMed Scopus (11) Google Scholar However, evidence of efficacy does not mean an absence of harm. This article is motivated by the observation that the safety of wearables and the potential health risks associated with their use have gone concerningly unexamined. The ubiquity1Bayoumy K. Gaber M. Elshafeey A. et al.Smart wearable devices in cardiovascular care: where we are and how to move forward.Nat Rev Cardiol. 2021; 18: 581-599Crossref PubMed Scopus (208) Google Scholar,2Wearable technology promises to revolutionise health care. The Economist.https://www.economist.com/leaders/2022/05/05/wearable-technology-promises-to-revolutionise-health-careDate accessed: December 22, 2022Google Scholar of these health-related technologies throughout the general population is somewhat historically unique and, in and of itself, necessitates rigorous and comprehensive investigations of safety. Further, case and cohort studies5Rosman L. Gehi A. Lampert R. When smartwatches contribute to health anxiety in patients with atrial fibrillation.Cardio Vasc Digit Health J. 2020; 1: 9-10https://doi.org/10.1016/j.cvdhj.2020.06.004Abstract Full Text Full Text PDF PubMed Scopus (11) Google Scholar, 6Andersen T.O. Langstrup H. Lomborg S. Experiences with wearable activity data during self-care by chronic heart patients: qualitative study.J Med Internet Res. 2020; 22e15873https://doi.org/10.2196/15873Crossref Scopus (15) Google Scholar, 7Wons O. Lampe E. Patarinski A.G. Schaumberg K. Butryn M. Juarascio A. Perceived influence of wearable fitness trackers on eating disorder symptoms in a clinical transdiagnostic binge eating and restrictive eating sample.Eat Weight Disord. 2022; 27: 3367-3377Crossref PubMed Scopus (1) Google Scholar, 8Blackstone S.R. Herrmann L.K. Fitness wearables and exercise dependence in college women: considerations for university health education specialists.Am J Health Edu. 2020; 51: 225-233Crossref Scopus (7) Google Scholar, 9Runkle J. Sugg M. Boase D. Galvin S.L. Coulson C.C. Use of wearable sensors for pregnancy health and environmental monitoring: Descriptive findings from the perspective of patients and providers.Digit Health. 2019; 52055207619828220PubMed Google Scholar, 10Watt A. Swainston K. Wilson G. Health professionals’ attitudes to patients’ use of wearable technology.Digit Health. 2019; 52055207619845544https://doi.org/10.1177/2055207619845544Crossref PubMed Scopus (7) Google Scholar have reported preliminary evidence of negative clinical and system-level outcomes, and additional adverse outcomes of concern have been suggested in expert opinion analyses.11Piwek L. Ellis D.A. Andrews S. Joinson A. The rise of consumer health wearables: promises and barriers.PLoS Med. 2016; 13e1001953Crossref PubMed Scopus (659) Google Scholar,12Xue Y. A review on intelligent wearables: uses and risks.Hum Behav Emerg Technol. 2019; 1: 287-294Crossref Scopus (27) Google Scholar Yet, these have not been systematically investigated. Given the broad adoption of wearable technologies and that they are marketed directly to consumers, there is a need to investigate (a) the nature and prevalence of negative outcomes, and (b) the risk factors that confer vulnerability to negative effects. This article calls for action by proposing a framework for investigating potential negative outcomes and their risk factors, with the current level of evidence13Burns P.B. Rohrich R.J. Chung K.C. The levels of evidence and their role in evidence-based medicine.Plast Reconstr Surg. 2011; 128: 305-310https://doi.org/10.1097/PRS.0b013e318219c171Crossref PubMed Scopus (1163) Google Scholar indicated for each variable (Figure). We observe that little peer-reviewed research has directly investigated the negative outcomes associated with wearables. Negative outcomes have been reported by a small number of case and cohort studies,5Rosman L. Gehi A. Lampert R. When smartwatches contribute to health anxiety in patients with atrial fibrillation.Cardio Vasc Digit Health J. 2020; 1: 9-10https://doi.org/10.1016/j.cvdhj.2020.06.004Abstract Full Text Full Text PDF PubMed Scopus (11) Google Scholar, 6Andersen T.O. Langstrup H. Lomborg S. Experiences with wearable activity data during self-care by chronic heart patients: qualitative study.J Med Internet Res. 2020; 22e15873https://doi.org/10.2196/15873Crossref Scopus (15) Google Scholar, 7Wons O. Lampe E. Patarinski A.G. Schaumberg K. Butryn M. Juarascio A. Perceived influence of wearable fitness trackers on eating disorder symptoms in a clinical transdiagnostic binge eating and restrictive eating sample.Eat Weight Disord. 2022; 27: 3367-3377Crossref PubMed Scopus (1) Google Scholar, 8Blackstone S.R. Herrmann L.K. Fitness wearables and exercise dependence in college women: considerations for university health education specialists.Am J Health Edu. 2020; 51: 225-233Crossref Scopus (7) Google Scholar, 9Runkle J. Sugg M. Boase D. Galvin S.L. Coulson C.C. Use of wearable sensors for pregnancy health and environmental monitoring: Descriptive findings from the perspective of patients and providers.Digit Health. 2019; 52055207619828220PubMed Google Scholar, 10Watt A. Swainston K. Wilson G. Health professionals’ attitudes to patients’ use of wearable technology.Digit Health. 2019; 52055207619845544https://doi.org/10.1177/2055207619845544Crossref PubMed Scopus (7) Google Scholar but these have not been followed by systematic investigations with rigorous designs. Furthermore, although there is review-level evidence describing technology-level risk factors such as measurement inaccuracies and privacy concerns,14Li H. Wu J. Gao Y. Shi Y. Examining individuals’ adoption of healthcare wearable devices: An empirical study from privacy calculus perspective.Int J Med Inform. 2016; 88: 8-17Crossref PubMed Google Scholar, 15Mahloko L. Adebesin F. A systematic literature review of the factors that influence the accuracy of consumer wearable health device data.in: Hattingh M. Matthee M. Smuts H. Pappas I. Dwivedi Y.K. Mantymaki M. Proceedings of the 19th IFIP WG 6.11 Conference on e-Business, e-Services, and e-Society. Springer, 2020: 96-107Crossref Scopus (15) Google Scholar, 16Scott H. Lack L. Lovato N. A systematic review of the accuracy of sleep wearable devices for estimating sleep onset.Sleep Med Rev. 2020; 49101227Crossref PubMed Scopus (62) Google Scholar, 17Cosoli G. Spinsante S. Scalise L. Wrist-worn and chest-strap wearable devices: systematic review on accuracy and metrological characteristics.Measurement. 2020; 159107789Crossref Scopus (75) Google Scholar characterization of individual-level risk factors (eg, psychological and medical vulnerabilities), and social-level risk factors (eg, access to health care) has thus far been largely limited to expert speculation.11Piwek L. Ellis D.A. Andrews S. Joinson A. The rise of consumer health wearables: promises and barriers.PLoS Med. 2016; 13e1001953Crossref PubMed Scopus (659) Google Scholar,12Xue Y. A review on intelligent wearables: uses and risks.Hum Behav Emerg Technol. 2019; 1: 287-294Crossref Scopus (27) Google Scholar Individual and social-level risks may be exacerbated when exaggerated marketing claims are made about validity and accuracy, as has been found to be the case for some popular devices.18Sperlich B. Holmberg H.C. Wearable, yes, but able…?: it is time for evidence-based marketing claims!.B J Sports Med. 2017; 51: 1240Crossref PubMed Scopus (40) Google Scholar Our aim is not to criticize or oppose these promising technologies, and we direct readers to recent discussions of their efficacy and potential in health promotion and management.1Bayoumy K. Gaber M. Elshafeey A. et al.Smart wearable devices in cardiovascular care: where we are and how to move forward.Nat Rev Cardiol. 2021; 18: 581-599Crossref PubMed Scopus (208) Google Scholar,3Mattison G. Canfell O. Forrester D. et al.The Influence of wearables on health care outcomes in chronic disease: systematic review.J Med Internet Res. 2022; 24e36690Crossref PubMed Scopus (11) Google Scholar Rather, this article aims to equip the field to empirically investigate negative outcomes and their risk factors so that a comprehensive evidence base can guide the implementation of consumer health wearable technologies. Health tracking technologies constitute behavioral interventions, and any behavioral intervention can precipitate positive or negative health outcomes. Although few would deny that this applies to wearables, there is a lack of empirical data about the prevalence of negative health outcomes or the individual traits that confer heightened risk for negative effects. Case studies suggest that wearable-induced health anxiety warrants empirical investigation. In one case report, a patient with atrial fibrillation and no psychiatric history developed health anxiety after acquiring a smartwatch, resulting in 12 emergency department visits despite repeated outpatient reassurance.5Rosman L. Gehi A. Lampert R. When smartwatches contribute to health anxiety in patients with atrial fibrillation.Cardio Vasc Digit Health J. 2020; 1: 9-10https://doi.org/10.1016/j.cvdhj.2020.06.004Abstract Full Text Full Text PDF PubMed Scopus (11) Google Scholar A recent qualitative investigation (n=27) of experiences with wearables among chronic heart patients found that several individuals reported reductions in anxiety from wearable use, whereas 1 participant reported new health-related anxiety.6Andersen T.O. Langstrup H. Lomborg S. Experiences with wearable activity data during self-care by chronic heart patients: qualitative study.J Med Internet Res. 2020; 22e15873https://doi.org/10.2196/15873Crossref Scopus (15) Google Scholar Two case reports constitute a weak level of evidence,13Burns P.B. Rohrich R.J. Chung K.C. The levels of evidence and their role in evidence-based medicine.Plast Reconstr Surg. 2011; 128: 305-310https://doi.org/10.1097/PRS.0b013e318219c171Crossref PubMed Scopus (1163) Google Scholar but together suggest that wearable use may increase health anxiety for some and decrease it for others. Further research is needed to identify prevalence rates and for whom this is a significant risk. The exacerbation of existing mental disorders and the recurrence of disorders in remission also warrant rigorous investigation. Preliminary research has suggested that wearable technologies may have exacerbating effects on eating disorders; for example, a randomized-controlled trial that included wearable technology as part of behavioral treatment among individuals diagnosed with an eating disorder found that a subsample of participants reported that the wearable negatively affected disordered eating behaviors.7Wons O. Lampe E. Patarinski A.G. Schaumberg K. Butryn M. Juarascio A. Perceived influence of wearable fitness trackers on eating disorder symptoms in a clinical transdiagnostic binge eating and restrictive eating sample.Eat Weight Disord. 2022; 27: 3367-3377Crossref PubMed Scopus (1) Google Scholar It is unknown whether recent developments in wearables, such as algorithms that provide nutrition recommendations, would mitigate these undesired effects. The field lacks empirical investigations into the impact of wearables on other mental disorders, but some expert commentaries11Piwek L. Ellis D.A. Andrews S. Joinson A. The rise of consumer health wearables: promises and barriers.PLoS Med. 2016; 13e1001953Crossref PubMed Scopus (659) Google Scholar,12Xue Y. A review on intelligent wearables: uses and risks.Hum Behav Emerg Technol. 2019; 1: 287-294Crossref Scopus (27) Google Scholar have remarked that classes of disorders most likely to be affected by wearable usage include depressive, sleep, and anxiety disorders. The data that wearables track may act directly on symptoms of these disorders (eg, rumination about sleep quality, reinforcement of negative beliefs about oneself). Wearables may also affect transdiagnostic processes that cut across psychiatric disorders, conferring increased risk for new or exacerbated psychological symptoms for some. For example, interoceptive awareness (the ability to identify, understand, and adaptively respond to one’s bodily sensations) and its potential counterpart, interoceptive avoidance (the avoidance of certain body sensations and activities that produce them), are transdiagnostic processes implicated in several Diagnostic and Statistical Manual of Mental Disorders diagnoses. Continuous quantitative data about interoceptively detectable processes (eg, heart rate) seems likely to alter users’ interoceptive awareness, but the field currently lacks data about how. Data from wearables are used by individuals to guide choices that directly affect health; thus, the same data that can inspire new, adaptive health behaviors can also lead to maladaptive health behaviors. Expert opinion articles have noted that inaccurate or incomplete data from wearables can lead to behaviors that harm health,1Bayoumy K. Gaber M. Elshafeey A. et al.Smart wearable devices in cardiovascular care: where we are and how to move forward.Nat Rev Cardiol. 2021; 18: 581-599Crossref PubMed Scopus (208) Google Scholar,4Brandes A. Stavrakis S. Freedman B. et al.Consumer-led screening for atrial fibrillation: frontier review of the AF-SCREEN International Collaboration.Circulation. 2022; 146: 1461-1474Crossref PubMed Scopus (11) Google Scholar,12Xue Y. A review on intelligent wearables: uses and risks.Hum Behav Emerg Technol. 2019; 1: 287-294Crossref Scopus (27) Google Scholar a concern that is exacerbated by exaggerated marketing claims that have sometimes been identified in validation studies of popular devices.18Sperlich B. Holmberg H.C. Wearable, yes, but able…?: it is time for evidence-based marketing claims!.B J Sports Med. 2017; 51: 1240Crossref PubMed Scopus (40) Google Scholar Consider an individual with a diagnosed heart condition who checks their smartwatch’s cardiac data during an exercise session because they are experiencing unusual shortness of breath. If the wearable inaccurately characterizes normal heart rate and rhythm (whether because of measurement error or because the smartwatch is unable to detect an arrhythmia) and the user is not aware of the device’s limitations, this inaccurate reassurance could cause a medical emergency. Others have raised the possibility of maladaptive health behaviors that can result from using wearables in medically healthy individuals, such as overexercising and disordered eating,8Blackstone S.R. Herrmann L.K. Fitness wearables and exercise dependence in college women: considerations for university health education specialists.Am J Health Edu. 2020; 51: 225-233Crossref Scopus (7) Google Scholar or maladaptive changes to health care utilization.5Rosman L. Gehi A. Lampert R. When smartwatches contribute to health anxiety in patients with atrial fibrillation.Cardio Vasc Digit Health J. 2020; 1: 9-10https://doi.org/10.1016/j.cvdhj.2020.06.004Abstract Full Text Full Text PDF PubMed Scopus (11) Google Scholar Individual factors such as knowledge about one’s health status, knowledge of device limitations, and adherence to current treatment and preventive screenings may reduce the likelihood of unhealthy behaviors. However, research has yet to empirically characterize risk and protective factors. Such data are critically needed to inform user or patient education strategies that can mitigate these concerns and prevent adverse physical health outcomes (eg, injuries, worsened cardiovascular health, or mismanagement of a known condition) for groups of individuals at risk. For example, wearables designed for clinical research (and not consumer use) frequently restrict the data viewable by the wearer. It is possible that this approach may optimize health outcomes from consumer devices for some groups of individuals, although research is needed to identify best practices in this regard. The level of trust that people place in a wearable is closely linked to how they use and respond to the technology. Technological trust—or lack thereof—is associated with perceptions of the accuracy and usefulness of the device,19Rupp M.A. Michaelis J.R. McConnell D.S. Smither J.A. The role of individual differences on perceptions of wearable fitness device trust, usability, and motivational impact.Appl Ergo. 2018; 70: 77-87Crossref PubMed Scopus (89) Google Scholar and its perceived compatibility with the users’ beliefs and values. Conflict with an individuals’ values is highlighted as a challenge across digital health,20Lyles C.R. Nguyen O.K. Khoong E.C. Aguilera A. Sarkar U. Multilevel determinants of digital health equity: a literature synthesis to advance the field.Annu Rev Public Health. 2023; 44: 383-405Crossref PubMed Scopus (2) Google Scholar and wearables present a distinct set of concerns in this regard. Incorporating continuous biomarker monitoring into one’s life is, ultimately, tied to beliefs about human-technology interactions. Although cultural variables have sometimes been included in nonrandomized usability and acceptability research,21Perski O. Short C.E. Acceptability of digital health interventions: embracing the complexity.Transl Behav Med. 2021; 11: 1473-1480Crossref PubMed Scopus (50) Google Scholar they are largely absent from published efficacy trials. Investigations of technology-relevant beliefs and the role that these play in technological trust and clinical outcomes are important to include in future trials. A vitally important discussion about equity in digital health has emerged in recent years. This discussion recognizes that technological are the of and in healthcare that are part and of influence the outcomes of technologies. Although we direct readers to comprehensive of digital health C.R. Nguyen O.K. Khoong E.C. Aguilera A. Sarkar U. Multilevel determinants of digital health equity: a literature synthesis to advance the field.Annu Rev Public Health. 2023; 44: 383-405Crossref PubMed Scopus (2) Google equity in digital a equity Digit Med. 2023; PubMed Scopus (1) Google Scholar in the of the present it is that the individual-level risk factors are investigated with into may be exacerbated or by evidence of differences in measurement accuracy is a concern for wearables. studies suggest that sensors of heart used in smartwatches, may be on of in wearable heart rate Digit Med. 2021; PubMed Scopus Google Scholar When the to and equity in clinical research and technology such as these are not when validation studies are on that would be identified with are The field in the possibility that other in accuracy that have not yet been identified (eg, or medical The with new and algorithms are to this as new differences in accuracy can be We to include of data using in research so that in accuracy can be in technology access and usability also warrant empirical other of digital S. K. D. A framework for digital health Digit Med. 2022; PubMed Scopus Google Scholar to the and usability of wearables include status, access to technology and individual differences (eg, who are or who have a physical The of these is in the of wearable people who are experiencing healthcare are also the most likely to be empirical this could affect the of health care For example, recent to data (eg, into health D. A. E. to wearable devices with behavioral and by health of a with consumer health Public Health. 2019; PubMed Scopus Google Scholar Although is a some individuals may be unable to an to a health This could thus have the of individuals who are most in need of health care to for a Wearables have been for the possibility of screening and for such as atrial A. Stavrakis S. Freedman B. et al.Consumer-led screening for atrial fibrillation: frontier review of the AF-SCREEN International Collaboration.Circulation. 2022; 146: 1461-1474Crossref PubMed Scopus (11) Google Scholar If this would constitute a advance for health. the potential negative system-level also be such as increased health costs associated with and health risks from from Americans in Health of from the Health for Health December Scholar wearable may lack access to care For for a positive can have (eg, medical that may affect health and future health care is also a of data about how wearable adoption how people use health care. is evidence to suggest that increased monitoring may contribute to among individuals who health L. Gehi A. Lampert R. When smartwatches contribute to health anxiety in patients with atrial fibrillation.Cardio Vasc Digit Health J. 2020; 1: 9-10https://doi.org/10.1016/j.cvdhj.2020.06.004Abstract Full Text Full Text PDF PubMed Scopus (11) Google Scholar and it that wearable use may affect when and people to their general and they at In future of wearables for and undesired effects on health care and the of care be empirically data about the on of the implementation of wearables into existing health care are about wearables raised by in qualitative J. Sugg M. Boase D. Galvin S.L. Coulson C.C. Use of wearable sensors for pregnancy health and environmental monitoring: Descriptive findings from the perspective of patients and providers.Digit Health. 2019; 52055207619828220PubMed Google A. Swainston K. Wilson G. Health professionals’ attitudes to patients’ use of wearable technology.Digit Health. 2019; 52055207619845544https://doi.org/10.1177/2055207619845544Crossref PubMed Scopus (7) Google Scholar have included the of data data and the potential for increased time of the negative individual-level outcomes may be or when wearables are used in with a but data are needed to characterize the and implementation potential of this of care. and ability to wearable usage with their patients may be on the of and the on may also by use (eg, whether use is or at the of a Given the number and of wearable devices and how frequently technologies and algorithms there are also to ability to current on the of individual may lack knowledge about how to for and negative health effects associated with wearables Consumer health wearables have been recognized for their to how people and their health. a literature efficacy for the use of wearables for some health and K. Gaber M. Elshafeey A. et al.Smart wearable devices in cardiovascular care: where we are and how to move forward.Nat Rev Cardiol. 2021; 18: 581-599Crossref PubMed Scopus (208) Google Scholar,3Mattison G. Canfell O. Forrester D. et al.The Influence of wearables on health care outcomes in chronic disease: systematic review.J Med Internet Res. 2022; 24e36690Crossref PubMed Scopus (11) Google Scholar The the general the potential for negative as by of this in recent L. Ellis D.A. Andrews S. Joinson A. The rise of consumer health wearables: promises and barriers.PLoS Med. 2016; 13e1001953Crossref PubMed Scopus (659) Google Scholar,12Xue Y. A review on intelligent wearables: uses and risks.Hum Behav Emerg Technol. 2019; 1: 287-294Crossref Scopus (27) Google Scholar and published in general for the and of fitness accessed: Scholar However, data about negative effects is limited to a small number of case and cohort and there is a of rigorous evidence for the or absence of associated with wearable Given their systematic investigations into the nature and prevalence of outcomes a a to we suggest a framework for investigating negative outcomes and their risk factors that can constitute an for future research on wearables. These data are needed to identify and the negative outcomes that are of to guide and to inform the of preventive user education strategies to who may be at risk for negative effects.

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