The assessment, serial evaluation, and subsequent sequelae of acute kidney injury (ASSESS-AKI) study: design and methods

Abstract

BackgroundThe incidence of acute kidney injury (AKI) has been increasing over time and is associated with a high risk of short-term death. Previous studies on hospital-acquired AKI have important methodological limitations, especially their retrospective study designs and limited ability to control for potential confounding factors.MethodsThe Assessment, Serial Evaluation, and Subsequent Sequelae of Acute Kidney Injury (ASSESS-AKI) Study was established to examine how a hospitalized episode of AKI independently affects the risk of chronic kidney disease development and progression, cardiovascular events, death, and other important patient-centered outcomes. This prospective study will enroll a cohort of 1100 adult participants with a broad range of AKI and matched hospitalized participants without AKI at three Clinical Research Centers, as well as 100 children undergoing cardiac surgery at three Clinical Research Centers. Participants will be followed for up to four years, and will undergo serial evaluation during the index hospitalization, at three months post-hospitalization, and at annual clinic visits, with telephone interviews occurring during the intervening six-month intervals. Biospecimens will be collected at each visit, along with information on lifestyle behaviors, quality of life and functional status, cognitive function, receipt of therapies, interim renal and cardiovascular events, electrocardiography and urinalysis.ConclusionsASSESS-AKI will characterize the short-term and long-term natural history of AKI, evaluate the incremental utility of novel blood and urine biomarkers to refine the diagnosis and prognosis of AKI, and identify a subset of high-risk patients who could be targeted for future clinical trials to improve outcomes after AKI.

Incidence, Outcomes, and Comparisons across Definitions of AKI in Hospitalized Individuals

“…We used administrative codes to identify medical conditions and procedures, which have limited accuracy, particularly for identification of diagnoses (23,39). Long-term mortality, CKD development, and CKD progression were not evaluated in this study but are important areas for future research (40).…”

Elevated BP after AKI

“…Baseline eGFR was calculated using the Chronic Kidney Disease Epidemiology Collaboration equation 42 on the basis of the most recent eligible serum creatinine concentration found in health plan databases during the 7-365 days before admission. 20,43,44 Dipstick proteinuria was classified as being present if there was a documentation of 1+ or greater on a urine dipstick (without concurrent positive nitrites or leukocyte esterase) up to 4 years before admission found in health plan laboratory databases. 45 Because high body mass index is known to be risk factor for BP elevations, 46 we only included patients with known height and weight within 2 years before hospitalization on the basis of ambulatory clinic visit measurements.…”

AKI Transition of Care

“…Currently, the Translational Research Investigating Biomarker Endpoints for AKI Study consortium (TRIBE-AKI, www.yale. edu/tribeaki) and the Assessment, Serial Evaluation, and Subsequent Sequelae in AKI (ASSESS-AKI) consortium will examine long-term kidney outcomes in several cohorts, including children who have survived cardiopulmonary bypass-associated AKI from at least three pediatric centers (63). As we await the results of these important studies, we propose that pilot and feasibility studies should be conducted to help mitigate the development and progression of CKD after episodes of AKI.…”