Economic impact and cost-effectiveness of urine neutrophil gelatinase-associated lipocalin following cardiac surgery

Abstract

Background. Acute Kidney Injury (AKI) is a serious postoperative complication of Coronary Artery Bypass Grafting (CABG) and an early diagnosis of AKI may improve outcome. uNGAL is a novel biomarker for the early detection of AKI. Objectives were to compare cost-effectiveness of uNGAL+Standard Monitoring (uNGAL-SM) vs. SM alone in CABG patients in Italy. Diagnostic schemes were:1) uNGAL: 5 consecutive determinations within the first 36h; 2) SM consisting of serum creatinine and clearance, sodium and urea tests: 2 assays in the first 24h, then 1set per day of hospitalisation. Methods. A decision model was adapted based on probabilities of developing AKI (RIFLE criteria), progression to chronic kidney disease, post-discharge recovery of renal function and death, decreased life expectancy, direct medical costs and patient health utility values. Treatment included medical support and renal replacement therapies. The basecase considered a 71 year old male and assumed that 25% of risk cases are prevented from progressing AKI. The model included data from literature and Italian experts' interviews. Univariate and probabilistic sensitivity analyses were performed. Results. Expected costs were: 1,399 for uNGAL-SM vs 1,501 for SM alone; expected QALYs were 10.26 vs 10.22, thus resulting in 136/QALY for uNGAL-SM and 147/QALY for SM. uNGAL-SM was dominant in all risk reduction scenarios. Sensitivity analyses showed that the model is very robust to variations of all variables tested with the exception of patients' life expectancy. Conclusions. uNGAL is an effective and cost-effective biomarker to be possibly recommended in the early diagnosis of AKI after CABG.