New Delirium Severity Indicators: Generation and Internal Validation in the Better Assessment of Illness (BASIL) Study

Abstract

Background: Delirium is a common and preventable geriatric syndrome. Moving beyond the binary classification of delirium present/absent, delirium severity represents a potentially important outcome for evaluating preventive and treatment interventions and tracking the course of patients. Although several delirium severity assessment tools currently exist, most have been developed in the absence of advanced measurement methodology and have not been evaluated with rigorous validation studies. Objective: We aimed to report our development of new delirium severity items and the results of item reduction and selection activities guided by psychometric analysis of data derived from a field study. Methods: Building on our literature review of delirium instruments and expert panel process to identify domains of delirium severity, we adapted items from existing delirium severity instruments and generated new items. We then fielded these items among a sample of 352 older hospitalized patients. Results: We used an expert panel process and psychometric data analysis techniques to narrow a set of 303 potential items to 17 items for use in a new delirium severity instrument. The 17-item set demonstrated good internal validity and favorable psychometric charac-S.K. Inouye and R.N. Jones contributed equally to this work. For the BASIL Study Team see Appendix A.

Lower surgical Apgar score is predictive on delirium in patients following off-pump coronary artery bypass grafting

“…Delirium is one of the common complications following cardiac surgery. On account of sedation and mechanical ventilation are routinely required after cardiac surgery, and most patients need vasoactive drugs to stabilize vital signs, therefore the occurrence of delirium has threatened the safety of patient postoperatively 6,[43][44][45][46] . Delirious patients often remove intubation and infusion tubes from the body, which seriously threatens the safety of patients' lives.…”

Delirium Item Bank: Utilization to Evaluate and Create Delirium Instruments

“…We previously described the study samples, the harmonization and linkage using item response theory (IRT) of four delirium instruments (CAM, DOSS, DRS-R-98, MDAS), and the creation of the DEL-IB [12]. Briefly, we used data from three studies: Adamis ( n = 200) [14], BASIL (Better Assessment of Illness Study) ( n = 352) [15, 16], and Detroyer ( n = 48) [13], each administering multiple delirium identification items and instruments to hospitalized adults age 65 years and older. Our analytic sample included 600 participants, contributing 1,623 delirium assessments.…”

“…Each source study administered at least two delirium assessment instruments, in part or in whole. The BASIL study administered the CAM and MDAS, and partial versions of the DOSS and MDAS [15, 16]. The BASIL study collected all measures using standardized approaches that have been previously validated against reference standard ratings [15].…”

Psychometric Properties of a Delirium Severity Score for Older Adults and Association With Hospital and Posthospital Outcomes

“…26 Delirium severity was quantified using the delirium severity score short-form (SF) 27 and longform (LF) score. 23,28 The delirium severity score was developed using advanced measurement methods and used a panel of delirium experts tasked with identifying domains and indicators of delirium severity that provided broad domain coverage across delirium symptoms, yielded high construct and content validity, enabled quick administration, and would be easy to use by trained raters. 22,29 The delirium severity score SF score is based on 6 observer-rated items (range, 0-13 points, with higher scores denoting worse delirium), and the delirium severity score LF is based on 17 observer-rated items (range, 0-21 points, with higher scores denoting worse delirium).…”

“… 18 Accordingly, we pursued the following multistep process: (1) systematic review of the medical literature on delirium severity and evaluation of the quality of existing tools 19 ; (2) psychometric synthesis and harmonization of the 3 most commonly used delirium severity instruments using advanced psychometric methods to generate an item bank 20 of delirium severity measures; (3) in-depth qualitative interviews with patients, caregivers, and nurses to ensure comprehensive inclusion of key domains of delirium severity 21 ; (4) a modified Delphi process involving an interdisciplinary panel of delirium experts to define domains and subdomains of delirium severity that do not overweight hyperactive symptoms 22 ; and (5) a prospective study to evaluate new delirium severity items using advanced measurement methods including item response theory. 23 The resulting instrument includes cognitive test items, patient self-report, and observer-rated items. Here we present our new delirium severity measure, the delirium severity score, to describe its distribution and internal reliability and to evaluate its association with clinically relevant outcomes at hospital discharge and after hospitalization, including length of stay (LOS), hospital costs, health care costs, rehospitalization, and cumulative mortality at 30 days, 90 days, and 1 year.…”