Long-Term Monitoring of Renal Transplant Patients by a CUSUM Test on Serum Creatinine

Abstract

A retrospective clinical assessment of kidney function change was performed on 38 kidney transplant patients over a median follow-up period of 128 weeks. Full records of the patients’ course were available to the clinician, while only the serum creatinine series of each patient was supplied to the computer on which a bilateral CUSUM test was implemented. The frequency of change assessed by the clinician was 146 out of 2,688 patient-weeks. The computer identified the function changes with 84.9% sensitivity and 94.3% specificity and the function deteriorations attributed to rejection with 88.9% sensitivity and 97.2% specificity. Thus we suggest an efficient long-term monitoring of the graft function with this simple and reliable statistical technique.

Statistical Process Control

“…Its migration to healthcare appears to have happened initially via applications to quality control in laboratory medicine in the 1950s. 6 Since the 1980s, the use of these methods has continued to expand, especially in monitoring individual patients, 7 for example following kidney transplantation, 8 for asthmatic patients, 9 and for patients with high blood pressure. 10 Statistical process control is now used across a wide range of areas in healthcare, including the monitoring and improvement of performance in hospitals and primary care, monitoring surgical outcomes, public health surveillance, and the learning curve of trainees undertaking medical or surgical procedures.…”