Objectives: This study was conducted to develop an android based patient decision aid (PDA) as a self-care instrument for patients after kidney transplant and its usability evaluation.

Methods: In this study, the systematic development process of Android-based self-care application for patients after kidney transplant based on Ottawa standard was included: scoping, assemble steering group, analysis of requirements, designing, develop of a prototype and system evaluation. The PDA is a self-triage system that will help early identification of risk symptoms in patients, and help manage them. System recommendations for risk signs are: Refer to the nearest hospital or healthcare center without delay, refer to the doctor and tell your doctor in the next visit. To identify patient care needs, a semi-structured interview with members of steering group, including patients and clinical experts, was conducted by the researchers. A prototype of the decision aid was made according to identified needs in the previous step. Finally, in order to evaluate its usability rate by using the System Usability Scale (SUS) questionnaire, it was used by exerts and patients.

Results: This study identified information needs, risk signs and steps that patients need to make appropriate decisions about them. The main capabilities of the decision aid are features such as reminders for appointment/test, time of taking medication, registration of symptoms, weight, blood pressure, body temperature, advising to patient in case of signs of risk, weight, blood pressure, body temperature and test results which were reported in the diagram. The mean score of system's usability evaluated by medical informatics specialists, clinicians, and patients were 88.33, 95, and 91.

Conclusions: PDAs was usable and desirable from the point of view of medical informatics specialists, clinicians and patients.