Smartphone Check-Ins could save transplanted kidneys

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Kidney transplantation within last 12 months * Treatment with tacrolimus * Routine aftercare planned at KTC * Ability to use a smartphone or tablet or with help of someone close by * For children \< 12 years parents have to take over the use of the smartphone * Patients who are willing and able to participate in the study and from whom written informed consent has been obtained prior to study participation or pediatric patients with parenteral consent * Ability to communicate in German or English * Adequate and stable renal function (eGFR \> 30 ml/min, Proteinuria \< 1g/g creatinine) eGFR will be determined according to CKD-EPI for adults \[81\] or Schwartz formula for children \[82\] Exclusion Criteria: * Patient with mental dysfunction or inability to comply with the study protocol or pediatric patients whose parents cannot comply with the study protocol * Any significant diseases or clinically significant findings, including psychiatric and behavioral problems, medical history and/or physical examination findings that would in the opinion of the investigator preclude the patient from participating in the study * History of alcohol or drug abuse with less than 6 months of sobriety * Participation in any other interventional clinical trial less than 1 month before participation in this study * Patients who have been institutionalized by official or court order * Patients with a combined kidney transplant or multi-organ recipients (other solid organ (e.g. pancreas) or bone marrow) * Presence of DSA with MFI \> 1000 at time of transplantation * Recurrence of underlying kidney disease (e.g. focal segmental glomerulosclerosis (FSGS) or atypical hemolytic uremic syndrome (aHUS) * Patient with active malignancy post-transplant with the exception of local, non-invasive, fully excised, cutaneous basal cell carcinoma, cutaneous squamous cell carcinoma, or cervical carcinoma in situ * Patients with clinically symptomatic congestive heart failure (CHF) or symptomatic coronary artery disease * Patients with documented (either by serology and/or nuclear acid testing (NAT) clinically active infections (e.g. with a known hepatitis B (HBV), hepatitis C (HCV), HIV, CMV or BK virus infection).