Numbers of older patients considered for kidney transplantation are increasing, with age being a significant factor influencing transplant outcomes. Particularly, chronological age is an inaccurate representation of patients’ functional ability since individuals with similar age can present with diverse physical and cognitive conditions. Frailty is a state of vulnerability and decline in functional ability. Emerging evidence indicates frailty is a risk factor for ‘hard’ clinical outcomes in adult kidney transplant recipients, independent of chronological age and comorbidities. Frailty is highly prevalent in adult kidney transplant recipients: 25.1 % are frail, and 33.0% are pre-frail. There is hence growing consensus that frailty might be a valuable criterion to guide clinicians’ risk prediction when evaluating patients for kidney transplantation. Additionally, mild cognitive impairment (MCI) is highly prevalent in this cohort (≤ 55.0%) and predictive of mortality. Links between frailty and MCI, and a modifying impact of psychosocial factors on frailty have been established in older adults, and therefore urgently require exploration in the kidney transplant cohort. Frail and/or cognitively impaired patients also use more healthcare resources, yet the impact of both conditions on resource use in kidney transplantation remains unexplored.
Our leading hypothesis is that frailty and MCI assessed pre-transplantation negatively impact patient survival, health-related quality of life (HR-QOL), graft survival, acute rejections, health care and societal costs, and quality adjusted life years (QUALYs) up to 2 years post-transplantation. We also postulate that chronic, low-grade systemic inflammation is predictive for changes in frailty and MCI up to 2 years post-transplantation.
The GERAS project aims to examine the prevalence of frailty and MCI in adult kidney transplant recipients, encompassing a bio-psychosocial and health economic perspective to enhance risk prediction in this study population. Our project is designed as a multi-center repeated measures study, nested in a nationwide long-term open prospective cohort study in the field of organ transplantation (the Swiss Transplant Cohort Study – STCS). A consecutive nationally representative sample of approximately 250 adult deceased- and living-donor kidney transplant recipients who participate in the STCS is being included across five Swiss kidney transplant centers. Study assessments are conducted immediately prior to transplantation, at 6 months, 1 and 2 years post-transplantation. Data sources include primary data collection from patients (adapted Fried Frailty Instrument, Montreal Cognitive Assessment, STCS Psychosocial Questionnaire and venous blood sampling), data from the STCS, and health economic data. Descriptive, competing risk survival and mixed effects analysis are performed to manage and analyze the data.