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Study Reveals Best Tools for Measuring Severity of Delirium in Hospitalized Patients

Boston - A study published today in JAMA Internal Medicine reveals the best assessment tools available to establish the severity of diagnosed delirium in hospitalized patients. Delirium is a common, serious, and often preventable complication among older adult patients. This is an important step in the management of delirium in older adults because the ability to quantify severity of the condition beyond merely rating delirium as present or not will help clinicians develop and monitor more effective treatments. The quality of the tools available to measure delirium severity has been recognized as highly important for tracking prognosis, monitoring response to treatment, and estimating burden of care both during and after hospitalization.

A research team including 21 scientists from Harvard Medical School, the Marcus Institute for Aging Research (Marcus Institute) at Hebrew SeniorLife, and 10 other academic organizations in the U.S. and China, searched databases including 9,409 articles that addressed measurement of delirium severity. They reviewed the full text of 228 and identified 42 different instruments to explore further. Applying pre-specified criteria related to frequency of use, methodologic quality, construct or predictive validity, and broad domain coverage, 6 final high-quality instruments were identified. They included, the Confusion Assessment Method, Confusional State Examination, Delirium-O-Meter, Delirium Observation Scale, Delirium Rating Scale, and Memorial Delirium Assessment Scale.  These measures will enable accurate measurement of delirium severity to improve clinical care for this common and devastating condition. The researchers hope this work will stimulate increased usage, and head-to-head comparison of these instruments. 

According to senior author of the study, Sharon K. Inouye, M.D., M.P.H., Director, Aging Brain Center, Marcus Institute and Professor of Medicine, Harvard Medical School, Beth Israel Deaconess Medical Center, “The time is right to advance measurement of delirium severity: Measurement is important, impactful, and efforts to stratify risk, target treatment, and monitor for outcomes are already possible and feasible with existing approaches.” First author, Richard N. Jones, ScD, of Brown University adds, “Measurements of delirium severity should play an important role in the advancement of clinical care and research for persons with delirium.”

An estimated 12 million older Americans experience delirium each year, at a cost of over $164 billion (2011) in annual healthcare expenditures. Delirium is distressing to patients and families, prolongs hospital stays, delays rehabilitation, and increases risks for dementia and death. Despite its importance for patient safety and public health, delirium is often unrecognized by clinicians, and effective treatments remain elusive. Moreover, presentation of delirium is heterogeneous and multifaceted, and measurement of delirium and its severity pose unique challenges.

Funding Sources:  This work was supported by grants from the National Institutes of Health [R01AG044518 (SKI/RNJ), R24AG054259 (SKI), K07AG041835 (SKI), P01AG031720 (SKI), and K24AG035075 (ERM)].

About the Hinda and Arthur Marcus Institute for Aging Research 
Scientists at the Marcus Institute seek to transform the human experience of aging by conducting research that will ensure a life of health, dignity and productivity into advanced age. The Institute carries out rigorous studies that discover the mechanisms of age-related disease and disability; lead to the prevention, treatment and cure of disease; advance the standard of care for older people; and inform public decision-making.

About Hebrew SeniorLife 
Hebrew SeniorLife, an affiliate of Harvard Medical School, is a national senior services leader uniquely dedicated to rethinking, researching and redefining the possibilities of aging. Based in Boston, the non-profit, non-sectarian organization has provided communities and health care for seniors, research into aging, and education for geriatric care providers since 1903. For more information about Hebrew SeniorLife, visit, follow us on Twitter @H_SeniorLife, like us on Facebook or read our blog.