DESCRIPTION (provided by applicant): Chi-yuan Hsu, MD, MSc is applying to renew his Mid-career Investigator Award in Patient Oriented Research (K24) in order to buttress his original research and mentorship efforts. The focus of the new research to be specifically supported by this K24 is incident end-stage renal disease (ESRD). A long-standing underlying theme of Dr. Hsu's research has been chronic kidney disease (CKD), including the transition from CKD to ESRD, which leads to his current interest in incident ESRD. This proposal addresses how we currently characterize new ESRD patients, how the reported number of new ESRD cases may be heavily influenced by threshold to initiate renal replacement therapy (RRT) and how early outcomes among incident ESRD patients are related to pre-ESRD clinical events. Aim 1: To determine the accuracy of how incident ESRD patients are currently characterized. Aim 2: To quantify how the number of incident ESRD patients vary by the threshold and timing of initiation of chronic dialysis. Aim 3: To better understand early outcomes among incident ESRD patients, including early death and recovery, and how they are related to pre-ESRD clinical events. Dr. Hsu has a very strong prior track record of mentorship and works within the rich, supportive and collegial institutional environment at UCSF. Continued K24 funding will permit Dr. Hsu to spend more time on research and mentoring and less time on administrative and clinical work.