Neurocognitive Function Changes With Extended-Release Tacrolimus Among Older Kidney Transplant Recipients

Inclusion Criteria: * Able to give informed consent for participation in the study * Patients who have regular outpatient follow-up at the Massachusetts General Hospital (MGH) transplant center * ≥1 year since the latest kidney transplantation * On IR tacrolimus as maintenance therapy * At a stable therapeutic tacrolimus level (5-10 ng/ml) over the last ≥3 months * Stable kidney function \[\<20% variability between the last two estimated glomerular filtration rate (eGFR)\] * Utilizing English or Spanish as the primary language Exclusion Criteria: * Dual organ transplantation * Rejection within the last three months * History of moderate to severe dementia (defined by Dementia Severity Rating Scale ≥19) * History of Parkinson's disease * Decompensated liver disease * Active cancer * Uncontrolled depression or anxiety * Blindness * Deafness * Intellectual disabilities * Pregnancy * eGFR \<15 mL/min/1.73 m2 at the time of enrollment * Total bilirubin \>3.0 mg/dL