Table 2.

Details of the apps used in the included studies.

Study	App functions and design	Medication adherence measure	Measure for evaluating app	App evaluation
Anglada-Martínez et al [33]	MEDPLAN. Drugs information, medication reminder alarm system, where patients confirm whether they have taken the drug or not. App designed by health professionals.	Simplified Medication Adherence Questionnaire (SMAQ), pharmacy refill method and number of days with missing dose.	Usability and satisfaction assessed through self-reported questionnaires.	When adherence was measured using the SMAQ, treatment adherence improved during the intervention phase (19.4%; P<.05), and the number of days with missed doses decreased (P<.05). The mean satisfaction score for Medplan was 7.2 ± 2.7 out of maximum of 10 points. 71.4% of participants said they would recommend the App to a friend, and 88.1% wanted to continue using it. They thought the application could be more useful in patients on polypharmacy, at the beginning of a treatment, for caregivers or for the elderly population.
Burbank et al [29]	Medication reminder, reminder for recording symptoms, feedback on its adherence and education about asthma. The App was designed by patients and health professionals.	Asthma Control Test. Child Asthma Self-Efficacy Questionnaire.	Questions about satisfaction.	In spite of the improvement in the control of asthma before and after the study, there were no significant differences (P=.53). However, the scores improved significantly for those who did not control asthma before the intervention (P=.03). Mean scores on self-efficacy before and after the study increased, but were not significant (P=.13). Although there were significant differences in preventing an asthma attack (P=.04). Satisfaction: 93%
Fallah and Yasini [18]	Reminders via alarms, instructions and information about medication. The App was designed by patients, health professionals, and technology specialists.	—a	Questionnaire for evaluating the application’s effectiveness and ease of use. The questions for evaluating its ease of use were taken from the System Usability Scale adapted for mobile applications.	No significant differences were found between the effectiveness or ease of use in either age group (greater and younger than 50). Both groups found the app effective and easy to use.
Goldstein et al [34]	—	Electronic pillbox: opening the pillboxes. Mobile application: electronic self-reports. The number of medications taken was divided by the number of medications prescribed.	Questionnaire for evaluating the acceptance, usefulness, satisfaction, willingness to recommend it and their opinion about the device.	Improves treatment adherence with both interventions (80%). No significant differences were found between the type of device and adherence (P=.87), neither were there between the condition and adherence (P=.48). Those in the mobile application group awarded higher scores on acceptance and usefulness of their device (P<.001). All participants preferred the intervention of the mobile application.
Grindrod, Li and Gates [35]	—	—	System Usability Scale. Questions in a group session: ease of use, user experiences, expected adoption, concerns about the potential for data entry errors, perceived quality of the provided information and preferences for the different characteristics.	The Pocket Pharmacist application received an ease of use score that was significantly lower when compared to the remaining applications (P<.001). They initially rated the experience of using the applications as frustrating, although that changed when they learned how to use them. They would use these applications if they someday needed to due to cognitive or health problems. The ideal application would possess characteristics that helped foster adherence and provide information.
Kang and Park [30]	HYPERTENSION MANAGEMENT APP. Reminders with alarms for taking medication and doctor’s appointments, recording blood pressure, recommendations about lifestyle and information on medication. The App was designed by patients and experts.	Modified Morisky Scale.	Questionnaire with a scale from 1 to 5 that evaluated perceived usefulness and satisfaction with each of the application’s contents.	The average scores on adherence increased significantly before and after the study from 4.2 to 5.2 out of a maximum of 6 points (P=.001). Perceived usefulness: 3.7. Satisfaction: 3.8 for medication reminders, 3.2 for alarms, 4.3 for recording blood pressure, 3.1 for the information sent, 3.4 for recommendations, and 3.8 for education about medication.
Mertens et al [31]	MEDICATION PLAN. Reminders via alarms, instructions and information about medication. The App was designed by health professionals.	Subjective adherence was determined by the A14-scale. Objective adherence was measured by number of medications each participant had to take each day.	Semistructured interviews.	The mean for subjectively assessed adherence there was a significant increase after the interventional phase from 50 to 54 out of a maximum of 56 points (P<.001). The app showed significant adherence for medication intake (P=.03). The majority of participants (n=22) stated that they would like to use the medication app in their daily lives.
Mira et al [32]	TUMEDICINA. Scans the bar codes on the medication box to provide information about its therapeutic objective, indications for taking it, interactions with other medications and its date of expiration. This information is stored as audio recordings. The App was designed by patients.	—	Group session and individual questionnaire for evaluating the characteristics and operation of the application.	The characteristics rated highest were the simplicity and clarity of the verbal messages (96.7%), the usefulness of the verbal messages (93.4%) and the clarity of the information provided (95.1%). No significant differences were found in the assessment of the satisfaction between patients with or without experience of using mobile telephones or browsing the Internet (P=.88). The people who rated the application the highest were persons who organized their medication in pillboxes, took notes on medication containers and took less than six drugs every day. Satisfaction: 8.3 out of 10.
Mira et al [9]	ALICE. Reminders with alarms for taking medication and carrying out healthy habits, images of drugs, instructions on how to take medication, SMS sent to caregivers in cases where the medication is not taken. The App was designed by patients, health professionals, and technology specialists.	Morisky Medication Adherence Scale. Questionnaire for evaluating rates of missed doses and medication errors.	Questions for evaluating the application: satisfaction, ease of use, performance, usefulness, reliability, acceptance, design, simplicity, accessibility, if they would recommend it and if it afforded them independence.	Treatment adherence improved in the experimental group (28%; P<.001) and in a lower rate of omitted doses (27.3%; P=.02). The application was not effective in reducing the rate of medication errors, it only decreased in patients who had reported committing 2 or more errors before the study (41.2%). Satisfaction: 8.5 out of 10. Persons without experience of information technologies said that using the application was not complicated.
Perera et al [23]	The application used by the control group contained a 24-hour medication watch. For the experimental group, in addition to the watch, it contained personalized messages about the levels of medication and immunoprotection in the patient’s body.	Medication Adherence Report Scale. Pharmacy prescriptions filled. HIV viral load.	Questionnaire for evaluating the satisfaction, perceived usefulness, ease of use, visual appeal, discretion and provision of information.	Greater treatment adherence in the experimental group according to the scores on the Medication Adherence Report Scale (40%; P=.03) and according to the viral load HIV (19%; P=.02). However, there were no significant differences in the pharmacy dispensing data (P=.18). The experimental group participants were more satisfied with the application than the control group and they rated it as informative, attractive and motivating. 79% said that adding the option of an alarm to remind about taking medication would be useful. 81% of the experimental group would recommend the application.
Shellmer et al [24]	TEEN POCKET PATH. Reminder of what medication must be taken and in what dose, confirmation that it had been taken, information about the type of transplant received and general information, such as telephone help lines. Caregivers received information as to whether the adolescents had taken their medication. The App was designed by patients and caregivers.	—	Post Study System Usability Questionnaire. Questions during one session: ease of use, viability, satisfaction, usefulness, simplicity of the reminder, warning messages sent to the caregivers and perceptions about long-term use of the application.	Users and caregivers found the application easy to use, effective, useful and they were satisfied with it. The caregivers said that they felt less need to constantly ask the adolescents about whether or not they had taken their medication.

^aMissing data.