Lessons for Successful Study Enrollment from the Veterans Affairs/National Institutes of Health Acute Renal Failure Trial Network Study

• Published in: Clinical journal of the American Society of Nephrology 2008-07, Vol.3 (4), p.955-961
• Main Authors: Crowley, Susan T, Chertow, Glenn M, Vitale, Joseph, O'Connor, Theresa, Zhang, Jane, Schein, Roland M H, Choudhury, Devasmita, Finkel, Kevin, Vijayan, Anitha, Paganini, Emil, Palevsky, Paul M
• Format: Article
• Language: English
• Subjects: Acute Kidney Injury - mortality; Acute Kidney Injury - therapy; Acute Renal Failure; Bias; Clinical Trials as Topic - methods; Critical Illness; Hemodiafiltration; Humans; Informed Consent; Intensive Care Units; Multicenter Studies as Topic; National Institutes of Health (U.S.); Patient Selection; Randomized Controlled Trials as Topic; Renal Dialysis; Research Design; Treatment Outcome; United States; United States Department of Veterans Affairs
• ISSN: 1555-9041; 1555-905X
• DOI: 10.2215/CJN.05621207

Design elements of clinical trials can introduce recruitment bias and reduce study efficiency. Trials involving the critically ill may be particularly prone to design-related inefficiencies. Enrollment into the Veterans Affairs/National Institutes of Health Acute Renal Failure Trial Network Study was systematically monitored. Reasons for nonenrollment into this study comparing strategies of renal replacement therapy in critically ill patients with acute kidney injury were categorized as modifiable or nonmodifiable. 4339 patients were screened; 2744 fulfilled inclusion criteria. Of these, 1034 were ineligible by exclusion criteria. Of the remaining 1710 patients, 1124 (65.7%) enrolled. Impediments to informed consent excluded 21.4% of potentially eligible patients. Delayed identification of potential patients, physician refusal, and involvement in competing trials accounted for 4.4, 2.7, and 2.3% of exclusions. Comfort measures only status, chronic illness, chronic kidney disease, and obesity excluded 11.8, 7.8, 7.6, and 5.9% of potential patients. Modification of an enrollment window reduced the loss of patients from 6.6 to 2.3%. The Acute Renal Failure Trial Network Study's enrollment efficiency compared favorably with previous intensive care unit intervention trials and supports the representativeness of its enrolled population. Impediments to informed consent highlight the need for nontraditional acquisition methods. Restrictive enrollment windows may hamper recruitment but can be effectively modified. The low rate of physician refusal acknowledges clinical equipoise in the study design. Underlying comorbidities are important design considerations for future trials that involve the critically ill with acute kidney injury.