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

Introduction

Acute kidney injury (AKI) is common after cardiac surgery and recognition with specific biomarkers may improve outcome. We assessed the impact and cost-effectiveness (CE) of urine neutrophil gelatinase-associated lipocalin (uNGAL) for AKI diagnosis compared with current methods.

Methods

We developed a decision analysis model to evaluate the CE of uNGAL plus standard diagnostic tests (for example, BUN, creatinine) compared with standard methods alone. The model was developed from the UK societal using costs per quality-adjusted life years (QALY). Model parameters were derived from the literature, UK economic data, and MD interviews. The base case was a 68-year-old male patient undergoing coronary artery bypass surgery. Sensitivity analyses were performed to determine how CE would vary with changes in the underlying model variables.

Results

The base case yielded expected costs of £4,244 and 11.86 QALYs for NGAL compared with £4,672 and 11.79 QALYs without NGAL. The CE ratio for the NGAL strategy was £358/QALY compared with £396/QALY for the standard regimen. CE increased as treatment effect - defined as the ability to prevent AKI progression (Injury or Failure) - for the therapy triggered by an elevated NGAL level rose. Sensitivity analysis showed that the model was most responsive to the probability of developing AKI and least sensitive to the cost of the NGAL test. Probabilistic sensitivity analysis demonstrated that the NGAL strategy was the more cost-effective option at a willingness-to-pay threshold of £30,000/QALY for each of the 1,000 simulations (Figure 1).

Figure 1

Probabilistic sensitivity analysis of incremental CE of NGAL vs standard methods.

Conclusions

Use of uNGAL appears to be cost-effective in the diagnosis of AKI after cardiac surgery.