Table 4.

A comparison of outcomes for the various studies.

Paper	Primary outcomes	Positive/negative outcomes
Timmers et al [32]	The information provided by the app satisfied the user needs. Users indicated the added-value of the symptom tracker diary to be high.	Successful implementation and use of a COVID-19 app for individuals An interactive map displayed the data collected through the app. COVID-19 screening results produced at the hospital were linked to app data. Health care providers and policy makers could use the data in developing their health care strategy based on the distribution of the reported infection load.
Yamamoto et al [33]	72 health observers were identified who were in close contact with a confirmed case. Among them, 57 adopted the app, while 14 used telephone as a means for conducting investigations. Before the introduction of the app, phone interviews required more than 2 hours and four epidemiological officers for contact tracing. After the introduction of the app, only one epidemiological officer was needed to perform health observations. The visualization of health observation data improved the investigation efficiency and comprehensiveness.	The ability of individuals to record health status on a daily basis was an important countermeasure against COVID-19. The use of the app improved the efficiency and completeness of the investigation process for COVID-19 cases carried out by epidemiological officers.
Zamberg et al [34]	Three documents related to COVID-19 were made available to medical staff via the mobile platform. Information was viewed 859 times, which accounted for 35.6% of total document views. The number of sessions per day increased significantly in the study period (more than doubled) compared with the sessions per day in previous weeks. Usability evaluation: 70 (83.3%) said it was easy to find information about SARS-CoV-2. On a 10-point Likert scale, the mHealtha solution scored 8.5 for time-saving and 7.6 for COVID-19 patient care assurance in daily practice.	Using the mHealth solution as a communication channel turned out to be effective within the organization for dissemination purposes during the pandemic. Daily practice was conducted by more confident and better-informed health care professionals.
Kodali et al [28]	Mixed evidence about the use of the app but mainly optimistic	Error correction, improved data collection quality, and user privacy should be considered in mHealth apps. Steps must be taken to ensure the reliability of the information provided by users. Therefore, predicting multiple verification of data entered by users could be critical.
Huckins et al [24]	With the rise of news relevant to COVID-19, college students spent more time seated, had fewer visits, and showed increases in anxiety and depression. The authors did not observe a return to baseline over the break, although they observed decreases in stress and depression that paralleled the typical drop after the final examination, suggesting some resilience in the face of COVID-19.	Mobile apps can be effectively used for tracking the mental health of college students.
Drew et al [26]	The app captures the dynamics of COVID-19 onset days before traditional measures such as positive tests, hospitalizations, or mortality. The collection emphasizes the potential usefulness of symptom monitoring in real time to help guide the allocation of resources for testing and treatment, as well as advising for tightening or loosening appropriate measures in specific areas.	With the participation of groups with underrepresented populations, the study aimed to encourage enrollment of individuals from populations that have traditionally been difficult to recruit. The study could capture correlations based on individual variations over time, a remarkable advantage over repetitive cross-sectional surveys that introduced significant variation between individuals.
Medina et al [29]	Mobile and home-based interventions were feasible for a wide range of conditions with a related risk of poor outcome from COVID-19. Approximately 10% of the patients in active monitoring presented symptoms such as shortness of breath that required escalation to a virtual provider. The median time to escalation ranged between 7 and 8 days. Patients with a pulse oximeter at home escalated a few days earlier due to reduced oxygen saturation measurements before subjective complaints of dyspnea. 2% of patients in active supervision were eventually admitted, and 3% were readmitted for persistent COVID-19 symptoms or due to complications of other underlying diseases. 9 patients monitored at home died, either due to complications related to COVID-19 or complications of another underlying disease.	Mobile engagement platforms have the potential to reduce the need for caregiver communication for patients whose symptoms are mild or persistent, freeing up the health care professionals to focus on patients who need it more.
Menni et al [30]	Besides more established symptoms such as high fever and a persistent cough, loss of smell and taste were possible prognostic factors for COVID-19. A combination of symptoms such as anosmia, fatigue, persistent cough, and loss of appetite together could identify individuals with COVID-19.	Physiological assessments of olfactory and taste function or nucleotide-based testing for SARS-CoV-2 could not be replaced by self-reporting. The authors did not know if anosmia was acquired before or after other COVID-19 symptoms, or during or after the illness.
Ross and Neuwirth [31]	This app was considered by the users as appropriate to learn and review skills relevant to COVID-19. More than 95% of respondents gave a score ≥5 for skills acquisition. 88% of respondents said it matched their health care needs. 93% of the respondents stated that the app gave them a better understanding. 87% of the respondents felt quite or very confident about the execution of the procedures, as shown in the lessons. 94% of respondents said that this particular COVID-19 training program made them feel ready to care for COVID-19 patients. 95% of respondents would suggest the application to other users.	Advantage over medical videos: It allowed the user to live the experience of seeing through a first-person view to learn through the eyes of the expert. The ability for a health care professional to instantly download locally (in a smart phone) material that can be accessed at any time in real time before, during, or after patient care interactions. When downloaded, the end user could access and view the tutorial at any time, regardless of network signal issues. Allowed health care professionals to navigate on their own or to jump to sections that were of greater importance to them
Bae et al [25]	Mobile app: usefulness showed the highest score, followed by satisfaction and perceived ease of use. Wearable vital sign monitoring perceived usefulness scored the highest, followed by perceived ease of use and satisfaction. For carers, there was an overall satisfaction score of 4.10/5.	During periods of pandemics and disasters, automated exchange of information between health care institutions plays an important role in dealing more efficiently with the problem at hand.
Ben Hassen et al [27]	Patients and doctors alike accepted the home hospitalization system very well.	Adjustments should be made for COVID-19 patients safely. Vital signs had to be measured by the patients themselves. Video communication between patients and doctors was added.
Bourdon et al [23]	Allowed doctors and patients to maintain social distance, avoiding three or four physical trips per person.	A physical appointment followed 27% of the teleconsultations. Average delay of 4.12 days between the onset of symptoms and advice, and <1 day for emergency episodes. There was 96% sensitivity and 95% specificity for the correct evaluation of the indication of a physical consultation and only 1.0% misdiagnoses.

^amHealth: mobile health.