App- and Wearable-Based Remote Monitoring for Patients With Myasthenia Gravis and Its Specialists: Feasibility and Usability Study

Abstract

Background: Myasthenia gravis (MG) is rare, chronic autoimmune disorder of the neuromuscular junction that requires specialized care and often lifelong treatment, facing challenges due to its rarity and the limited availability of specialists. Telemedical solutions in specialized centers hold considerable promise in bridging this gap by increasing access to this care to a broader patient population in a timely manner. However, there is no research regarding interventional remote care solutions in the field of MG to date.

Objective: This study aimed to assess the feasibility and usability among patients with MG and specialists of a telemedicine platform, tailored to patients with MG and designed to facilitate remote monitoring, treated in a specialized center.

Methods: The telemedicine platform consisted of an app for patients and a web-based portal for physicians. Over a period of 3 months, 30 patients continuously monitored their vital parameters through external devices, including a digital spirometer and a wearable (activity tracker). Furthermore, patients completed 7 different patient-reported outcome measures (PROMs) through the app at predefined intervals. Specialists could review this monitoring data and adjust therapy as necessary. In addition, communication between patients and physicians was facilitated through a chat module. Feasibility was evaluated by total adherence rates for completing PROMs within the app, alongside the collection of spirometry and wearable data. Furthermore, user satisfaction was assessed among both patients with MG and physicians at the end of study.

Results: Total adherence rates ranged from 74.3% (1830/2464) to 97.9% (327/334) across all data types, with the highest adherence observed for PROMs (1139/1179, 96.6%), followed by spirometry (293/334, 87.7%) and wearables (1830/2261, 80.9%). Notably, patients wore the wearable longer than required by protocol and conducted a higher number of spirometry measurements during the study than required per protocol (median 20 h/d [IQR 15-24] vs 14 h/d and median 49 [IQR 15-59] measurements vs 11 measurements, respectively). Technical issues and discomfort with wearables were factors affecting lower adherence in some patients. The System Usability Scale yielded a median score of 85 indicating "excellent usability." In addition, results from a more detailed user evaluation questionnaire showed high levels of user satisfaction among both patients and health care professionals across diverse categories, including their experience of the care program, communication, and evaluation of the program.

Conclusions: Remote monitoring of patients with MG through the telemedical platform demonstrated good feasibility and acceptability, as evidenced by above-average adherence rates and user satisfaction for both patients and physicians. The majority of patients wanted to continue using the app. These findings highlight the potential for user-friendly digital tools to enhance care for patients with MG, although addressing technical challenges and ensuring patient comfort with wearables are essential for optimal implementation. Further research involving larger cohorts and longer study duration is warranted to validate these findings.

Keywords: PROMs; activity tracker; app; autoimmune disorder; communication; digital platform; digital tool; feasibility; mobile phone; myasthenia; myasthenia gravis; remote monitoring; spirometry; telemedicine; usability; wearable data; wearables; web-based portal.

Figure 1.. Schematic overview of telemedical platform and its features (MyaLink): transmission and simultaneous integration of sensor-based data into the app is implemented by bluetooth from coupled external devices (wearable or digital spirometer). In addition, the platform facilitates the collection of patient-reported outcome measures (PROMs) through the app and a communication module enables interaction between patients and physicians. Health data can be shared with specialists who can review monitoring parameters through the web-based system and make therapy adjustments as needed. The data is transmitted between patient and physicians with double encryption (AES256, Advanced Encryption Standard). PROM: patient-reported outcome measure.

Figure 2.. Monitoring plan and frequencies of assessed parameters: Active (PROMs, respiratory function assessment) and passive data (wearable data) were collected during the study period. PROMs data were collected weekly or monthly, depending on the questionnaire. Respiratory function assessment, assessed through breath count test and spirometry, was conducted weekly by the protocol. The collection of wearable data was continuous, with steps aggregated by the hour. PROMs: patient-reported outcome measures; MG-ADL: myasthenia gravis activities of daily living; MG-QoL15r: myasthenia gravis quality of life, revised; SSQ: single simple question; PASS: Patient Acceptable Symptom State; CFS: Chalder Fatigue Scale; HADS: Hospital Anxiety and Depression Scale.

Figure 3.. Adherence of spirometry measurements: The blue circles represent the end-of-study visit for each patient, while the red line indicates week 12, marking the duration of the study. Each black vertical line indicates when a spirometry measurement was assigned according to the study protocol (weekly intervals). Patients were given a 7-day window until the next weekly assignment for measurement to qualify as “completed.” The black dots mark the times when the patient actually performed the spirometry measurement. Each measurement from the digital spirometer was timestamped and subsequently automatically transmitted to the app through bluetooth, with the values being integrated accordingly. FVC: forced vital capacity.

Figure 4.. Adherence rates for wearable data from the activity tracker: Days since baseline visit on the X-axis, with patients represented on the Y-axis and the adherence rate per patient in the column on the right side. Days with wearable usage of at least 14 hours per day were classified as compliant (marked in green). A wearable hour was counted if at least one heart rate measurement value was recorded per hour. Days with less than 14 hours of wearable usage per day were marked as red. Days without any recorded heart rate measurements were marked in gray and excluded from the analysis.

Figure 5.. User evaluation for patients: The questionnaire was divided into 3 categories: “Experience with the care program,” “Communication and Interaction” and “Evaluation of the program.” All 17 questions could be answered using a 4-point Likert scale ranging from 1 (strongly agree) to 4 (strongly disagree).

Figure 6.. User evaluation for health care professionals: The questionnaire was divided into 3 categories: “Experience with the care program,“ “Communication and Interaction,” and “Evaluation of the program.” All 17 questions could be answered using a 4-point Likert scale ranging from 1 (strongly agree) to 4 (strongly disagree). Depending on the role within the study team (eg, physician and study nurse), only certain questions in the questionnaire could be answered.

Figure 7.. The System Usability Scale (SUS) uses a 10-item questionnaire with 5 response options for respondents, ranging from strongly agree to strongly disagree. Due to rounding, the percentage for Question 2 (“I feel confident using the app”) is 99% instead of 100%.