Researchers Work to Better Measure Delirium Severity in Older Patients

BOSTON – Delirium – an acute confusional state characterized by acute decline in cognition – can present as inattention, disorientation, lethargy or agitation, and perceptual disturbance. Most common among older hospitalized patients, delirium can lead to poor outcomes, including prolonged hospital stays, deep psychological stress for patients and their families, functional decline, and in worst cases, death. With in-hospital mortality rates for older patients with delirium at 25 to 33 percent and annual health care costs attributable to delirium in excess of $182 billion in the United States alone, delirium has garnered increasing attention as a worldwide public health and patient safety priority.

In a study published in the journal Dementia and Geriatric Cognitive Disorders, researchers at Beth Israel Deaconess Medical Center (BIDMC) and Hebrew SeniorLife reported on their effort to improve and validate tools used to assess the severity of delirium. The aim was to more accurately define methods for detecting and measuring delirium symptom severity, which could in turn lead to improved prevention and treatment for patients at risk.

“While a variety of tools for the assessment of delirium severity currently exist, most delirium severity instruments have not been developed with advanced measurement methodology or evaluated with rigorous validation studies,” said lead author Sarinnapha M. Vasunilashorn, PhD, of the Division of General Medicine at BIDMC and Assistant Professor of Medicine at Harvard Medical School (HMS) and in Epidemiology at the Harvard T.H. Chan School of Public Health. “Our study has laid the foundation for a new, more fully conceptualized delirium severity measure.”

Accurately identifying the severity of delirium that a patient experiences is critical to developing effective treatment. For any medical disorder, severity is a complex topic and may mean different things to different stakeholders. From a clinical perspective, severity may reflect the likelihood of an adverse outcome or the urgency for symptom treatment. For patients and their families, severity may impact the level of distress they experience or impair patient function and recovery.

By performing a literature review and using an expert panel process and advanced data analytic techniques, the researchers identified a set of questions or observations for use in developing a new instrument that measures delirium severity. Moving beyond the classification of delirium present/absent, delirium severity represents a potentially important outcome for evaluating preventive and treatment interventions, and tracking the course of patients. The process revealed several characteristics of an ideal instrument: It should address a broad spectrum of delirium symptoms, should be proven to be reliable, yield diagnosis by severity rating and criteria, and be able to be administered quickly and easily by minimally trained raters.

Using this information, the researchers developed a set of 17 criteria that they agreed captures the severity of delirium, including but not limited to: level of consciousness, emotional dysregulation, disorganized thinking, disorientation and hallucination. The study indicates that high-quality delirium severity instruments should ultimately have immediate relevant application to clinical care and quality improvement efforts.

“Moving beyond consideration of delirium as present or absent, delirium severity represents an important outcome for evaluating preventive and treatment interventions, and tracking the course of patients,” said principal investigator Sharon Inouye, MD, MPH, Director of the Aging Brain Center at the Hinda and Arthur Marcus Institute for Aging Research at Hebrew SeniorLife.

This work was supported by grants from the National Institutes of Health (R01AG044518 [S.K.I./R.N.J.], K01AG057836 [S.M.V.], R03AG061582 [S.M.V.], R01AG030618 [E.R.M.], K24AG035075 [E.R.M.], R24AG054259 [S.K.I.], K07AG041835 [S.K.I.], P01AG031720 [S.K.I.]) and the Alzheimer’s Association (AARF-18-560786 [S.M.V.]).