Table 1 Inclusion and exclusion criteria for the ASSESS-AKI Study.

Adult participants aged 18 years to 89 years.

Inability to provide informed or surrogate consent.

Children aged greater than one month to less than 18 years old at cohort entry.

Died prior to the three-month study visit.

Documented "baseline" serum creatinine defined as the outpatient, non-emergency department test value nearest to the index hospitalization within 7 and 365 days prior to admission using an IDMS-traceable serum creatinine assay.

Incarcerated, institutionalized, or otherwise unable to participate in the study within a home, community, or clinical setting.

In the TRIBE-AKI consortium, pre-operative serum creatinine results from an IDMS-traceable assay obtained within seven days before cardiac surgery can be used to define "baseline" kidney function for the subset of participants who are undergoing non-urgent cardiac surgery.

Enrolled in an active interventional study at the three-month in-person study visit.

For pediatric participants in TRIBE-AKI, a pre-operative serum creatinine concentration measured in the local hospital clinical laboratory among patients scheduled for elective cardiac surgery.

Actively pregnant or breastfeeding. Prior chronic hemodialysis, peritoneal dialysis (lasting ≥three months), or estimated GFR <15 ml/min/1.73 m2 not receiving renal replacement therapy. History of solid organ and/or hematopoietic cell transplants.

Acute glomerulonephritis diagnosed clinically or by biopsy.

Clinically significant urinary tract obstruction, confirmed by imaging.

Hospitalization involving acute nephrectomy.

History of multiple myeloma.

Hepatorenal syndrome.

Metastatic cancer or systemic cancer receiving active treatment.

New York Heart Association Class IV heart failure prior to index admission.

Predicted survival of 12 months or less as determined by the participant's treating physician or Clinical Research.

Center Principal Investigator.

AKI participants who remain hospitalized 90 or more days after the AKI episode.

ESRD at the time of the three-month study visit.

Unable to provide at least 1.5 mL of plasma for adults at the Inpatient visit.

Unable to provide at least 3 mL of urine for adults at the Inpatient visit.

Unable to provide at least 10 mL of blood for adults and 1 mL of blood for children at the three-month visit.