Reporting of Outcomes and Outcome Measures in Studies of Interventions to Prevent and/or Treat Delirium in the Critically Ill: A Systematic Review.

To inform development of a core outcome set, we evaluated the scope and variability of outcomes, definitions, measures, and measurement time-points in published clinical trials of pharmacologic or nonpharmacologic interventions, including quality improvement projects, to prevent and/or treat delirium in the critically ill. We searched electronic databases, systematic review repositories, and trial registries (1980 to March 2019). We included randomized, quasi-randomized, and nonrandomized intervention studies of pharmacologic and nonpharmacologic interventions. We extracted data on study characteristics, verbatim descriptions of study outcomes, and measurement characteristics. We assessed quality of outcome reporting using the Management of Otitis Media with Effusion in Children with Cleft Palate study scoring system; risk of bias and study quality using the Cochrane tool and Scottish Intercollegiate Guidelines Network checklists. We categorized reported outcomes using Core Outcome Measures in Effectiveness Trials taxonomy. From 195 studies (1/195 pediatric) recruiting 74,632 participants and reporting a mean (SD) of 10 (6.2) outcome domains, we identified 12 delirium-specific outcome domains. Delirium incidence (147, 75% of studies), duration (67, 34%), and antipsychotic use (42, 22%) were most commonly reported. We identified a further 94 non-delirium-specific outcome domains within 19 Core Outcome Measures in Effectiveness Trials taxonomy categories. For both delirium-specific and nonspecific outcome domains, we found multiple outcomes in domains due to differing descriptions and time-points. The Confusion Assessment Method-ICU with Richmond Agitation-Sedation Scale to assess sedation was the most common measure used to ascertain delirium (51, 35%). Measurement generally began at randomization or ICU admission, and lasted from 1 to 30 days, ICU/hospital discharge. Frequency of measurement was highly variable with daily measurement and greater than daily measurement reported for 36% and 37% of studies, respectively. We identified substantial heterogeneity and multiplicity of outcome selection and measurement in published studies. These data will inform the consensus building stage of a core outcome set to inform delirium research in the critically ill.