Introduction

Wearable digital health technology includes devices worn on the body connected digitally to an external device and provides disease monitoring, diagnostics, alerts, or other clinical care services for the wearer or caregiver (Friend et al., 2023). These devices, known as “wearables” for short, have seen a rapid rise in the healthcare technology market over the past decade, especially in recent years: their market size value increased from $15.4 billion in 2020 to $71.91 billion in 2023 (“Wearable Technology Market Size”, 2023). Wearables range in uses and types, commonly utilizing particular sensors that assist in tracking physiological parameters such as heart rate, cognitive impairment, and even diabetes and pregnancy. The integration of sensors, microelectronics, and computing power allows health wearables to achieve a unique real-time and accurate detection and analysis of the user’s physiological and pathological information; instantaneous measurements can provide valuable information in situations ranging from everyday, low-effort exercise to intensive disease diagnosis and treatment (Lu et al., 2020).

Like many devices in the healthcare industry, wearable health technology has unique concerns, with quite a substantial one involving ethical considerations. Ethics in healthcare stem from the analysis of medical technologies, and the moral decision-making process that occurs in their production and usage (Taylor, n.d.). For instance, ethical concerns arise due to the heightened surveillance of a user’s personal physiological information via consumer wearable health technology. Moral questions arise due to privacy and security issues caused by third parties accessing private user data and dubious informed consent of a user and their data privacy upon the usage of a wearable (Sui, 2023). Companies that produce and disseminate health wearables possess huge amounts of personal data that are susceptible to unlawful data attacks and tampering: so, is the decision-making process that healthcare wearable companies employ in constructing their devices and data security practices ethical and safe for the user?

The answer to this question is complex and often dependent on the company and type of wearable. A need is identified to provide consumers with a more comprehensive and empowered knowledge surrounding informed consent and the safe use of health wearables. Each unique type of health wearable presents individual ethical concerns depending on the device type: wearables can fall into the categories of 1) health and safety monitoring, 2) chronic disease management, and 3) rehabilitation (Lu et al., 2020). The most notable ethical concerns for most health wearables involve data security and privacy for health and safety monitoring, as seen in existing literature (list sources here). However, a gap exists in identifying specific ethical concerns for wearables used for chronic disease management and rehabilitation. Consumers should recognize ethical concerns surrounding health wearables they intend to purchase or utilize and feel empowered to make well-informed decisions surrounding their autonomy over personal physiological data and clinical decisions. This literature review discusses specific ethical concerns from all four types of health wearables and provides recommendations for consumers and users.

Health and Safety Monitoring

Health and safety monitoring devices are health wearables used for real-time measurement of physiological parameters, such as gait, blood oxygen, and heart rate to inform nursing decisions (Lu et al., 2020). From children to the elderly, a high-quality independent lifestyle can be achieved through wearable health devices that track relevant health parameters consistently. Health and safety monitoring can also be linked to the diagnosis and treatment of diseases; continual tracking allows for clarity on neurological disorders or respiratory illnesses. However, with these devices comes ethical concerns about data storage, transferring sensitive data to healthcare providers, and securing the vast amount of data accumulated from constant tracking.

Insecure mHealth Apps and Digital Hospital Systems

An example of a health wearable in which ethical issues regarding insecure data storage and transfer arise are wearables for pregnancy. Constant monitoring during pregnancy can provide safe and effective tracking of the health of the mother and the baby. Many external, environmental, physical, and behavioral factors can influence a pregnancy (Alim & Imtiaz, 2023). Wearable sensors have been developed to measure parameters such as blood glucose level, blood pressure, heart rate, and other biometric data, which is then transferred from the pregnant individual to their healthcare provider. Biometric data is then analyzed to determine fetal heart rate, fetal movement, a woman’s body temperature, stress levels, and blood circulation- parameters that are quite sensitive and personal to the baby and its mother. The collected information is subsequently transferred to healthcare providers through mHealth (mobile health) apps, mobile apps, or wireless smartwatches. Used in many health wearables including those for pregnancy, mobile apps and mHealth apps are especially susceptive to penetration by cyber threats, due to outdated or unpatched software, improper authentication, insecure data storage and transmission, and additional weaknesses (Baran, 2024). Digital hospital systems often use healthcare technology industry-standard protocols, such as HL7, which occasionally lack robust security features. Consumers of wearable health devices do not consent to the possibility of their data being leaked or tampered with: unless the wearable device company and the healthcare provider are clear about the safety and security of their device, the device cannot be considered ethically safe for the user. Potential users may be advised to research their intended wearable and review the company’s data security practices.

Third-Party Usage of Personal Data

Another instance of health and safety monitoring devices utilizing mHealth apps or mobile apps are devices that track mental health. A method of data collection known as ecological momentary assessment (EMA) is used to collect self-reported, real-time, and repeating measurements of an individual’s mood, experiences, and behaviors within their regular environment, and obtain information on symptoms such as emotional reactivity and sleep level, which are generally associated with depression (Sequeira et al., 2019). EMA data is most commonly collected from smart bands and smartwatches with embedded sensors; 71% of mental-health monitoring wearables are worn on the wrist according to a literature study by Ahmed et al. (2023), as are most health and safety monitoring wearables. The host devices connected to the wrist wearables are smartphones and computers; data is transferred wirelessly back and forth from the wearable to the host. Data held in the cloud, or wirelessly transferred through Bluetooth such as EMA data in mental health wearables can be used by third parties, and personal health data can be sold to advertisers or other users without the participant's consent or knowledge (da Silva, 2023). Users provide implied consent to the wearable company through the purchase of the device; however, they unintentionally and without knowledge can consent to the third-party usage of their data. The unknowing dissemination of personal data by wearable companies puts ethics into question.

Securing Vast Amounts of Data

Wearable devices that track physiological parameters for the diagnosis and treatment of diseases run into similar data storage and privacy issues as health and safety monitoring devices. Due to the need for continual tracking to diagnose and treat a unique disease, healthcare providers constantly obtain sensitive physiological information through third-party mobile applications or hospital systems, with data tracking spanning notably long periods of time. For instance, growing evidence suggests that sensory and motor changes may precede the clinical manifestations of Alzheimer’s disease; tracking sensory and motor changes can detect a neurological or neurodegenerative disease 10-15 years before diagnosis (Kourtis et al., 2019). Wearable devices can measure movement, speech and language, nervous system function, sleep changes, executive dysfunction, and more to detect Alzheimer’s earlier. However, overwhelming work lies ahead to ensure that wearable devices for disease tracking and diagnosis are ethical. Wearable disease-tracking devices - such as ones used to monitor Alzheimer's - need to secure and manage vast amounts of information that come with continual tracking, over months, years, or even decades. Users that intend to utilize their wearable for longer periods of tracking time should understand the importance of a secure and well-protected medical IT infrasture for collecting their personal data, and a wearable company that can process and protect their data for long periods.

Chronic Disease Management

Wearable health devices for chronic disease management focus on collecting data/ monitoring user parameters throughout the day, and analyzing various indicators to inform the treatment of chronically ill patients (Lu et al., 2020). Sensors are still utilized for these wearables and measure similar parameters to health and safety monitoring, like heart rate, energy expenditure, and sleep quality. The difference, however, in wearables for chronic disease management is the implementation of self-tracking and self-management of the user’s chronic illness. Users are given continual feedback on their disease condition, which can lead to heightened autonomy and involvement with treatment choices and productive lifestyle changes (Mattison et al., 2022). For instance, smartwatches such as the Apple Watch are noted as common wearables to utilize for self-monitoring of chronic diseases. Patients with diabetes can self-monitor symptoms such as frequent urination and sleep disturbances (Köhler, 2024). Diabetes is a chronic metabolic disorder that can be controlled by changes in lifestyle, making it valuable to understand physiological parameters that depend on diet and physical activity (Chakrabarti et al., 2022). Sensors within the smartwatches can measure heart rate, blood pressure, blood oxygen level, step count, and sleep quality, and be coupled with non-invasive sensors that conduct continuous glucose monitoring. The information obtained from sensors can be correlated with the type of food intake and blood sugar level of the patient to provide recommendations for proper diet, and daily recommended fitness levels based on the user’s age, sex, daily activity, and medications. These physiological parameters for diabetes, as well as other chronic conditions, need to be - to an extent - self-monitored to match goals in managing the user’s chronic illness. Ethical concerns arise from the possible lack of user autonomy and provider trust in making relevant decisions regarding their health, and the sociological implications arising from a lack of inclusive and diverse research in self-tracking wearables.

Lack of User Autonomy in Decision-Making

The decision to adopt a self-tracking device is not always completely voluntary. It is sometimes difficult to draw a line between self-tracking practices that are voluntary, and those that are externally imposed on the user by healthcare providers. Users who are prescribed self-tracking devices for chronic health management are sent home with the expectation that they adhere to the prescribed self-monitoring program pushed by a medical professional who may not understand the chronically ill patient’s unique needs or barriers to self-tracking. These providers may influence users to adopt behavioral patterns deemed “standard” or “normal”, though these “standard” practices may be decided incorrectly or unethically (Lupton, 2016). Even when self-tracking is taken up fully voluntarily by the wearable user, the data it collects will ultimately influence the user’s decision-making process regarding their health. A question arises: what would the user decide about their health if the device was not collecting data and influencing their decisions? Some of the user’s agency in making daily choices about their actions can be taken away or infringed upon by devices that continually aim to influence user behavior, which presents ethical concerns regarding patient autonomy (Wieczorek, 2022).

Sociological Implications

Looking at self-tracking ethics from a sociological perspective, much research has focused on privileged social groups who track their health indicators because these groups already conform to the societal ideals of the “responsibilised, self-managing and entrepreneurial citizen” (Lupton, 2016). There is little information on how elderly people, people from monitory or ethnic groups, and people with poor literacy skills or disabilities can engage with self-tracking of chronic illness. Self-tracking health wearable devices hold promise for individuals managing chronic illness by empowering them to have more impact and autonomy in their well-being and meeting their health goals. However, ethical concerns that arise from the self-tracking of physiological parameters through wearable devices such as smartwatches shine a light on the necessity for consumers to understand whether self-tracking wearable devices fit and are accessible for their lifestyle, and whether they are comfortable with health decisions being influenced by a factor outside of themselves and their healthcare provider.

Rehabilitation

Rehabilitation-based health wearables are generally used for sports and cognitive rehabilitation and as aids for individuals with disabilities. In modern surgical practices, rehabilitation wearables are occasionally utilized in postoperative monitoring for operations conducted for issues spanning early-stage lung cancer to total hip replacement surgery, since the early postoperative period is when multiple serious complications are prevalent in most surgical interventions. Common complications such as hypotension, pneumonia, and mobility issues that arise with issues post-operation can result in significant morbidity and mortality, increased length of hospital stay, and substantial costs, to name a few (Amin et al., 2021). These complications can arise due to the influence of significant physiological stressors caused by surgical insult; the resulting stress hormone result can cause serious systemic changes. Though wearables for early postoperative monitoring are fairly new, wearables can provide a discrete, continuous, and remote collection of physiological data such as cardiac monitoring and physical activity, potentially improving the detection of complications. Most of these wearables are wrist-mounted and report high levels of patient satisfaction. With this context, well-developed wearables that assist and protect the health and safety of individuals undergoing rehabilitation post-operation are vital. However, along with the privacy and data security concerns encompassing most health wearables, rehabilitation devices present unique ethical concerns surrounding the unique clinical background of the user and the necessity of implementing a treatment plan securely and ethically.

Consideration for User’s Unique Clinical Context

Postoperative rehabilitation devices are unique in that they are inherently intended to be lifesaving devices, meant to provide key information on pathological movements that could occur after surgical injury and reduce common complications. So, the collected physiological data must be continual, real-time, accurate, and most importantly- analyzed within each patient’s unique clinical context. Ethical concerns begin with the initial prescription of the wearable; what information is the clinician utilizing to distinguish between patients requiring in-patient monitoring and low-risk patients that can go through early discharge and safely and effectively use wearable monitoring? Is that decision influenced by a desire to reduce departmental costs or improve key performance indicators in the department? Is the device intended to produce functional improvement in the patient, or to address surgical side effects, and how can the clinician modify the wearable device treatment plan to address individual concerns? These questions all require analysis through an ethical lens: how do clinicians ensure their decision-making process is unencumbered by external benchmarks and entirely structured with the patient’s best interests? Furthur issues such as a clinician’s possible inadequate expertise in health wearables, and patient preferences for receiving feedback (through machine-based systems, human interactions, scheduled vs.

on-demand), need to be considered to recommend a rehabilitation wearable ethically (Chakraverty, 2024).

Implementation Plan for Rehabilitation Using Wearables

Rehabilitation wearables encounter limited useability in perioperative care due in part to their newness and unique functionality which presents the possibility of medical-legal concerns and unclear responsibilities of key stakeholders, as these factors generate a potential for unethical medical practices. However, due to the medical potential of rehabilitation wearables, an implementation plan to use the devices ethically and effectively in clinical practices can be beneficial. A recommendation developed by Bellini et al. (2024) outlines a plan of implementation in postoperative care that accounts for different stakeholders and compliance with regulations and focuses on analyzing potential issues before implementation. They emphasize the need for a monitoring team to be made up of all healthcare professionals usually involved in managing surgical patients, along with engineering, technical staff, and medical-legal staff associated with the wearable to create a chain of liability in the occurrence of a critical event. This is especially important since some wearable device systems have been noted to not effectively distinguish pathological movements from normal ambulation, which can lead to a failure in detecting a serious health event. For instance, a wireless ear-worn activity recognition body sensor network device was produced to collect biomechanical data on patients’ activities of daily living after events that require significant rehabilitation. The unsupervised system was not able to differentiate a seizure from normal movement in clinical trials (Aziz et al., 2011). Consumers considering the usage of rehabilitation-based wearables in their everyday lives, especially in postoperative care, should ensure that a structured and effective implementation plan has been made with a clinician. Without a secure plan, individual stakeholder failures can cause a treatment plan to become unethical and potentially harmful for the rehabilitation wearable user.

Conclusion

The most common ethical concerns surrounding wearable digital health technology involve the privacy and data security issues that may arise through the constant monitoring and subsequent sharing of a user’s physiological information via unstable or unprotected data systems or used by third parties without implicit user consent. However, each type of wearable health device presents additional unique ethical concerns due to their intended usage and the health concerns of the wearable users. Depending on whether the health wearable is used for 1) health and safety monitoring, 2) chronic disease management, or 3) rehabilitation, an informed consumer must be mindful of the ethics surrounding the device they wish to utilize. The consumer must understand the importance of trust, confidence, and individual agency over their physiological data (“Healthcare Online Training”, 2023). Wearable technology must be transparent in its intentions and practices regarding data and usage, and the consumer should speak with their healthcare provider and conduct their own research if needed about the unique issues that may arise with the usage of their intended device. Health-based wearables present a modern and influential opportunity to improve health outcomes for many distinct and multi-faceted disease states and health concerns. There is always a need in healthcare, however, to look closely at the ethics that arise with medical technology created for direct patient care, and these devices are no exception.