*2.1.2 App design considerations*

The key underlying premise for developing the MG mhealth app was to help patients track their symptoms, treatments and exacerbating factors in between visits to their doctor so that they can self-manage their disease better and so that their HCP can review information in the app to get a more accurate and more comprehensive summary of what happened since their last visit. We selected the validated MG quality of life tool called the Myasthenia Gravis Activities of Daily Living profile (MG-ADL) [86] to capture data about patient symptoms. The app also allows tracking of some common physical activities such as walking the dog or climbing stairs which are important to the patient. This provides them with the ability to track how well they are doing for important activities which may not be considered to be 'activities of daily living'.

Benefits and goals of tracking symptoms, medication use, health system use and exacerbating factors we identified included, 1) patients may identify reasons for disease worsening earlier with use of the app and, in some cases, be able to act on the information themselves; e.g., get more sleep or avoid situations which make their disease worse (benefit to In-Charge and Adaptive Manager). 2) Patients may make the visit with their HCP more efficient and productive, giving them more time to ask questions that are important to them (benefits Worrier, Adaptive Manager). 3) Patients may receive treatment escalation sooner, if the HCP is better able to tease out worsening of underlying disease from a string of bad days (benefits all patient types). These benefits are communicated to the patient throughout the app, to remind them of the benefits and reinforce use of the app.

Most patients (75% of women and 56% of men) do not like the side-effects of prednisone and resist dose escalations [87]. Making it easy for patients to capture more granular information about their medication use may be helpful for physicians to tailor doses and minimize the dose escalations or minimize the duration of a dose escalation. Rather than asking patients to enter all their medication data into the app and track detailed usage, it may be as valuable to capture the main 2 most problematic medications used in the treatment of MG and ask the patient periodically whether they used it as prescribed and if not, why not. That information would be easier for the patient to enter and may be just as helpful to the HCP as a much more detailed log of medication use.

Fear, uncertainty, change and stigma are a big part of the MG experience [88]. Using more reassuring and calming language, without promising anything that cannot be delivered by the app is a good way of addressing anxiety. A root cause of stigma is ignorance. Providing useful facts about MG to the patient about self-management and how to explain their disease to others could help decrease uncertainty and stigma and help the patient cope better with unavoidable change. These facts and messages can be entered into a fact and message bank that can be displayed to the patient randomly, helping to keep the app fresh and educating patients at the same time. In future iterations, the app may wish to include an optional cognitive behavioral therapy component and/or a mood or anxiety tracker.

Patients who desire more control over the app (In-Charge and Adaptive Manager) are given an opportunity to make changes to the settings for a variety of features. Expert review identified that some of the features that patients could control (for example, what would be released to their HCP in the report) would only increase their anxiety and have a paradoxical effect on patients perceived control over the app. It was recommended that the control over the HCP report be removed as it did not impact the patient. The reports provided to patients were also harmonized to look more like what was provided to the physician so that they would not be disoriented when having a conversation with their HCP.

Patients with MG frequently experience exhaustion, which is independent of muscle weakness, the hallmark of the disease. This means that patients with MG spend a lot of time in bed, unable to move, but still able to think and perform cognitive tasks. We recommended that the app provide a function to lock the aspect ratio so that patients can view the app in the more convenient portrait mode while lying down.

Almost half of patients with MG experience reduced social positivity and physical activity, increasing their chances of becoming depressed and becoming deconditioned. Future iterations of the app will consider adding a gratitude journal and/or a cognitive behavioral therapy component. Future iterations could also provide the patient with a physical activity program to prevent physical deconditioning.
