Coenrolment of critically ill patients into multiple studies: patterns, predictors and consequences
IntroductionResearch on coenrolment practices and its impact are limited in the ICU setting. The objectives of this study were; 1) to describe patterns and predictors of coenrolment of patients in a thromboprophylaxis trial, and 2) to examine the consequences of coenrolment on clinical and trial outcomes.
In an observational analysis of an international thromboprophylaxis trial in 67 ICUs, we examined the coenrolment of critically ill medical-surgical patients into more than one study, and examined the clinical and trial outcomes among coenrolled and non-coenrolled patients.
Among 3746 patients enrolled in the Prophylaxis for ThromboEmbolism in Critical Care Trial, 713 (19.0%) were coenrolled in at least one other study (53.6% in a randomized trial, 37.0% in an observational study, and 9.4% in both).
Six factors independently associated with coenrolment (all p<0.001) were illness severity (odds ratio [OR] 1.35, 95% confidence interval [CI] 1.19-1.53 for each 10 point APACHE II score increase), substitute decision-makers providing consent, rather than patients (OR 3.31, 2.03-5.41), experience of persons inviting consent (OR 2.67, 1.74-4.11 for persons with >10 years experience compared to persons with none), center size (all ORs >10 for ICUs with >15 beds), affiliation with trials groups (OR 5.59, 3.49-8.95), and main trial rather than pilot phase (all ORs >8 for recruitment year beyond the pilot). Coenrolment did not influence clinical or trial outcomes or risk of adverse events.
Coenrolment was strongly associated with features of the patients, research personnel, setting and study.
Coenrolment had no impact on trial results, and appeared safe, acceptable and feasible. Transparent reporting, scholarly discourse, ethical analysis, and further research are needed on the complex topic of coenrolment during critical illness.
Published on: 2013-01-08