Strengths and Limitations
AKI, kidney dysfunction
KIDNEY DYSFUNCTION, SECONDARY
This multicenter prospective study has several strengths, including the robust high-quality data available in a large, prospective, multicenter study allowing for the detailed exploration of the impact of fluid balance on AKI diagnosis. Furthermore, the study has long-term kidney-specific outcomes for the cohort.Despite these strengths, there are several limitations of this secondary analysis. Our findings were limited by clinically obtained serum creatinine, and weights and urine output were not collected. However, weights were available for 97% of potential patient days, and this analysis imputed missing values; therefore, misclassification is likely infrequent. Because the PENUT database only included daily weights from the first 2 postnatal weeks, our conclusions are limited to this period. Longer observation periods are necessary to extend our findings. We note that there are other variables, such as clinical conditions and management practices, that may result in changes in weight and are not captured in this analysis. Third, although defining AKI by neonatal modified KDIGO definitions is the current standard for this patient population, this may not be the optimal marker for detection of kidney dysfunction in premature neonates.