The study was conducted in 2 phases (Figure 1).
Phase 1: app development. m-DAKBAS was formed within the theoretical framework of knowledge, behavior, and self-efficacy. That is, patients with diabetes should demonstrate positive care behaviors to protect their foot health. If a decrease in ulcer and amputation rates is desired, optimal foot care behavior should be realized. Individuals’ self-efficacy needs to increase for self-care knowledge to become a behavior.28,29 Self-efficacy is defined as “the belief of an individual’s ability in executing and realizing courses of action to obtain some attainments.”30 Individuals having these beliefs and attitudes tend to demonstrate behaviors appropriate toward meeting a goal.28
The text content of the app is in Turkish and was prepared in line with the latest evidence and guidelines. The content was presented to 6 experts (a lecturer in the Department of Endocrinology, 4 nurse lecturers who conducted research about diabetes and diabetic foot, and a physician in the Department of Undersea and Hyperbaric Medicine).
Software process. Mobile apps on the web were analyzed. There was a limited number of diabetes-related Turkish apps on the web. The researcher, who is a diabetes nurse specialist, is familiar with the profile of patients with diabetes in Turkey. For design and use convenience, the patient profile was taken into consideration when interfaces were developed. Service was bought for the software of the application, and the development process took 3 months. During that time, 3 meetings were held with the information technologies (IT) specialist. In the first meeting, the researcher informed the IT specialist about the text content and other features that were desired. The domain name and hosting were bought for the researcher for 1 year. In the second meeting, the IT specialist presented the interface design of the app. In the third meeting, the administrator and user panels were introduced by the IT specialist. In this meeting, misunderstandings about the expectations of the tool were clarified, and final revisions were made accordingly.
Framework of the m-DAKBAS.
• The application was designed as a web-based mobile app.
• The system has admin (health professional) and user (patients with diabetes) panels.
• The app can be used on mobile phones with IOS and Android operating systems.
• The app has a password login system for the storage and safety of personal information.
• The user panel has a home screen interface, 8 interfaces, and 8 subinterfaces.
• There are “get information” and “prevention” interfaces that provide the text that contains information about the definition of diabetic foot, risk factors, and proper foot care for prevention.
• There is a messaging interface for administrator communications. Personal messages with motivational and informative content were prepared, including the following: “Dear …. your blood glucose values seem to be very good. Congratulations; It is great!” “You have a moisturizer for your feet,” “Healthy diet, regular exercise, and medicine are important for blood glucose control in diabetes,” “HbA1c test gives the 3-month blood glucose average,” and “It is good to keep HbA1c values under 7% to avoid the adverse effects of diabetes.”
• The section on foot observation allows patients to enter data. There are checkboxes for dryness, swelling, ulcer, warmth, callus, fissure, tingling, burning, unusual sensation, and pain assessment in the foot observation section. Patients can check the boxes of their own findings and send them to the system administrator.
• The blood glucose section includes text boxes where morning, noon, and evening fasting and postprandial blood glucose levels can be recorded.
• The “test yourself” interface enables patients to test their knowledge about foot care and enables them to improve their knowledge.
• In the “photo share” interface, patients can take and send a photo of their foot.
Health personnel/system administrators can confirm users’ records from the admin panel, update information content, monitor negative findings reported by the patient and enable timely intervention, and send diabetes-related reminders and informative messages. They can also monitor users’ blood sugar levels, regular and irregular data entry, and foot health status.
Pilot study. The pilot study was conducted with 10 patients with diabetes who met the sample group research criteria. Informed consent was obtained for the pilot study. Patients with diabetes used the mobile app for 10 days; they were asked to send their blood glucose level each time they measured it and to send their foot observations daily. During this period, some revisions were made in line with the feedback provided on the device. For example, initially patients could not see their right or wrong answers in the “test yourself” interface or messages from the admin; these deficiencies were corrected.
Phase 2: app evaluation. After the pilot study, the physician in the diabetes outpatient clinic referred patients who met the research criteria to the researcher. The patients who agreed to participate in the study were included after their written consent was received. The researcher assigned patients to the experimental or control groups according to the order in a computer-based randomization list previously created. The convenience sampling selection was made among the patients who visited the diabetes outpatient clinic. All participants were given training about personal foot care and foot observations in the patient training room by the researcher (a diabetes nurse specialist). Participants in the control group were given a training by the researcher through verbal instruction about the information in the content of m-DAKBAS (definition of diabetic foot, risk factors, protective precautions, and daily foot care). The training was given once and was not reviewed again. Patient training took about 30 minutes. Forms were completed in 15 minutes.
For participants in the experimental group, the m-DAKBAS app was downloaded to their mobile phone by the researcher, and participants were given a username and password. Participants were instructed how to use the application by the researcher after a sufficient number of trials performed together (eg, patients were asked to send sample blood glucose values and foot observation data). The duration of the use of the app was 6 months (24 weeks).
Throughout the 24 weeks, participants were asked to use the app to send their blood glucose levels each time they were measured and also to send foot observations daily, because it is recommended that patients with diabetes observe their feet every day.1,4,12 The researcher communicated with participants in the experimental group through the app. Using the admin panel, the researcher followed the participants’ frequency of using the app, their blood glucose levels, and foot care, and also tried to find solutions to the medical problems encountered. The data sent by the participants were analyzed by the researcher on a weekly basis and reviewed to monitor for potential patient problems/concerns. The participants were told that they could share photos if they had a problem with their feet. Use of the “test yourself” interface was optional, and data from this field were not evaluated by the researcher. In the case of abnormal findings, the researcher communicated with the participant through messaging, phone, or face-to-face interviews. Based on these records, participants were provided feedback about foot observations and blood glucose values. Participants were sent SMS reminders if the tasks were not completed. Participants who completed the research period were given an appointment for the post-test after 24 weeks. Post-test forms (DFKF, FSCBS, DFCSES, m-DAKBAS evaluation form, and foot care findings,) were completed by the researcher.
Statistical analysis. Data from the questionnaires were manually entered into the SPSS for Windows version 24.0 package program. P < .05 was accepted as statistically significant. Normality distribution of the data was tested using the Shapiro-Wilk test, which indicated that the data were not distributed normally (P > .05).
Average ± standard deviation for numerical variables (age, HbA1c, duration of diabetes, and BMI) as well as number and percentage values for categorical variables (sex, educational level, employment status, smoking status, and m-DAKBAS evaluation) used frequency and description. The Wilcoxon test was used to compare the scores of the information form (DFKF) as well as the behavioral (FDCBS) and self-efficacy (DFCSES) scales at different times. The Mann-Whitney U test was used to compare independent groups.
Chi-square test was used to test the normal distribution of categorical variables between experimental and control groups (sex, educational level, employment status, and smoking status). The t test was used to test the normal distribution of numerical variables between the experimental and control groups (age, HbA1c, duration of diabetes, BMI). McNemar test was used to determine if there were differences on a dichotomous dependent variable between 2 related groups (foot examnination findings).
Ethics review and approval. In line with the Declaration of Helsinki, written approval was obtained from the Clinical Studies Ethics Committee and the department where the study was conducted (2017/69 decision number dated February 27, 2017). Patients were expected to use their own internet packages when sending data. The patients had no concern about this. Written informed consent was obtained from all participants.