Related Experiment Video
Updated: Jul 6, 2026
A Large Animal Model for Acute Kidney Injury by Temporary Bilateral Renal Artery Occlusion
Published on: February 2, 2021
Lessons for successful study enrollment from the Veterans Affairs/National Institutes of Health Acute Renal Failure
Susan T Crowley1, Glenn M Chertow, Joseph Vitale
1Renal Section (111F), VA Connecticut Healthcare System, 950 Campbell Avenue, West Haven, CT 06516, USA. susan.crowley@yale.edu
Background And Objectives:
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.
Design, Setting, Participants, & Measurements:
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.
Results:
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%.
Conclusions:
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.
Insights
Clinical trial design can impact efficiency, especially in critically ill patients. Modifying enrollment windows and addressing informed consent issues can improve recruitment for acute kidney injury trials.
Area of Science:
- Critical care medicine
- Nephrology
- Clinical trial design
Background:
- Clinical trial design elements can introduce recruitment bias and reduce study efficiency.
- Trials involving critically ill patients are particularly prone to design-related inefficiencies.
Purpose of the Study:
- To systematically monitor and categorize reasons for nonenrollment in the Veterans Affairs/National Institutes of Health Acute Renal Failure Trial Network Study.
- To identify modifiable and nonmodifiable factors affecting patient recruitment in critical care trials.
Main Methods:
- Systematic monitoring of enrollment in the Acute Renal Failure Trial Network Study.
- Categorization of nonenrollment reasons into modifiable and nonmodifiable factors.
- Analysis of patient screening, eligibility, and enrollment data.
Main Results:
- Of 1710 potentially eligible patients, 1124 (65.7%) enrolled.
- Impediments to informed consent excluded 21.4% of potentially eligible patients.
- Modifying an enrollment window reduced patient loss from 6.6% to 2.3%.
Conclusions:
- The study's enrollment efficiency was favorable compared to previous intensive care unit trials.
- Addressing informed consent barriers and optimizing enrollment windows are crucial for recruitment in critical care trials.
- Underlying comorbidities are important design considerations for future trials involving critically ill patients with acute kidney injury.
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