Delirium has a dramatic impact on older people but is frequently undiagnosed

Published in the September issue of the Journal of Hospital Medicine, the findings show that delirium -- or acute confusion -- is common among older adults in hospitals and nursing homes. It has a negative impact on cognition and independence, significantly increases the risk of developing dementia, and triples the likelihood of death. Yet this common, acute condition is frequently either undiagnosed or accepted as inevitable.

Led by the Regenstrief Institute and Indiana University, the research team reviewed 45 years of research encompassing 585 studies. They found that one in three cases of delirium were preventable and are calling for delirium to be identified and treated early to prevent poor long-term prognosis.

"As a geriatric psychiatrist I have seen that around 50 per cent or people with dementia in hospital develop delirium," said co-author Dr Chris Fox, of Norwich Medical School at the University of East Anglia.

"This is because in addition to having dementia, they have multiple risk factors that can predispose and precipitate delirium -- including serious illnesses and pre-existing cognitive impairment. In addition, hospital staff commonly label the signs as dementia related and do not pick up the delirium."

"We need to develop better mechanisms for diagnosing delirium so that prompt treatment regimes can be initiated."

In general patient groups, more than 60 per cent of delirium cases are not recognised or treated, and significant numbers of elderly patients leave hospital with ongoing delirium which has been missed.

The authors, led by Dr Babar Khan of the Regenstrief Institute and Indiana University School of Medicine, said that delirium could be prevented by eliminating restraints, treating depression, ensuring that patients have access to glasses and hearing aids, and prescribing classes of antipsychotics that do not negatively affect the aging brain. They also noted the need for a more sensitive screening tool for delirium, especially when administered by a non-expert.

"Delirium is extremely common among older adults in intensive care units and is not uncommon in other hospital units and in nursing homes, but too often it is ignored or accepted as inevitable," said Dr Khan. "Delirium significantly increases risk of developing dementia and triples likelihood of death. It cannot be ignored."

Co-author Dr Malaz Boustani, of the Regenstrief Institute, Indiana University School of Medicine and Wishard Healthy Aging Brain Center, said: "Having delirium prolongs the length of a hospital stay, increases the risk of post-hospitalization transfer to a nursing home, increases the risk of death and may lead to permanent brain damage."

'Delirium in Hospitalized Patients: Implications of Current Evidence on Clinical Practice and Future Avenues for Research -- A Systematic Evidence Review' by Mohammed Zawahiri (Regenstrief Institute and IU Center for Aging Research), Noll L. Campbell (Regenstrief Institute, Purdue University and Wishard Health Services), Chris Fox (University of East Anglia), Eric Weinstein (Tri-State Pulmonary Associates), Arif Nazir (IU School of Medicine), Mark Farber (IU School of Medicine), John Buckley (IU School of Medicine), and Alasdair MacLullich (University of Edinburgh) is published online by the Journal of Hospital Medicine on September 18.

The study was supported by the National Institute on Aging and the National Institute of Mental Health.