Health Care Resource Utilization and Costs of Persistent Severe Acute Kidney Injury (PS-AKI) Among Hospitalized Stage 2/3 AKI Patients.

Background Persistent severe acute kidney injury (PS-AKI) is associated with worse clinical outcomes, but there are no data on costs of PS-AKI. We compared costs and health care resource utilization for inpatients with PS-AKI versus not persistent severe AKI (NPS-AKI) overall and by ICU use.Methods This retrospective observational study included 126,528 adult US inpatients in the PINC AI Healthcare Database (PHD), discharged from January 1, 2017, to December 31, 2019, with KDIGO stage 2 or 3 AKI (by serum creatinine [SCr] criteria) during hospitalization, length of stay (LOS) =3 days, and =3 SCr measurements. Patients were categorized as PS-AKI (defined as stage 3 AKI lasting =3 days or with death within 3 days or stage 2/3 AKI (by SCr criteria) with dialysis within 3 days) or NPS-AKI. Generalized linear model regression compared LOS and costs during index hospitalization (total cohort) and 30 days postdischarge (survivors of index hospitalization), adjusted for patient, hospital, and clinical characteristics.Results Among 126,528 patients with stage 2/3 AKI, 30,916 developed PS-AKI. In adjusted models, compared with NPS-AKI, patients with PS-AKI had 32% longer total LOS (+3.3 days), 45% longer ICU LOS (+2.6 days), 46% higher total costs (+$13,143), 58% higher ICU costs (+$15,908), and during 30 days postdischarge 13% longer readmission LOS (+1.0 day), 22% higher readmission costs (+$4049), and 12% higher outpatient costs (+$206) (P<0.005 for all). Relative LOS and cost differences for PS-AKI versus NPS-AKI were similar for ICU (n=57,947) and non-ICU (n=68,581) patients.Conclusions: Among hospitalized patients with stage 2/3 AKI, PS-AKI was associated with significantly longer LOS and higher costs during index hospitalization and 30 days postdischarge, overall, and in ICU and non-ICU patients. Preventing PS-AKI among patients with stage 2/3 AKI may reduce hospital LOS and costs.