Under-detection of delirium and impact of neurocognitive deficits on in-hospital mortality among acute geriatric and medical wards.
BACKGROUND
Delirium is a neuropsychiatric disorder, triggered by medical precipitants causes. Study aims were to describe the prevalence and impact on in-hospital mortality of delirium identified through ICD-9 codes as well as evidence of neurocognitive deficits demonstrated in a population of older patients admitted to acute medical wards.


METHODS
This was a prospective cohort multicenter study of 2521 older patients enrolled in the "Registro Politerapie SIMI (REPOSI)" during the years 2010 and 2012. The diagnosis of delirium was obtained by ICD-9 codes. Cognitive function was evaluated with the Short Blessed Test (SBT) and single SBT items were used as measures of deficits in attention, orientation and memory. Combination of deficits in SBT items was used as a proxy for delirium. Logistic regression was used to evaluate the association with in-hospital mortality of delirium and combined deficits in SBT items.


RESULTS
Delirium was coded in 2.9%, while deficits in attention, orientation, and memory were found in 35.4%, 29.7% and 77.5% of patients. Inattention and either disorientation or memory deficits were found in 14.1%, while combination of the 3 deficits in 19.8%. Delirium, as per ICD-9 codes, was not a predictor of in-hospital mortality. In contrast, objective deficits of inattention, in combination with orientation and memory disorders, were stronger predictors after adjusting for covariates.


CONCLUSIONS
The documentation of delirium is poor in medical wards of Italian acute hospitals. Neurocognitive deficits on objective testing (in a pattern suggestive of undiagnosed delirium) should be used to raise awareness of delirium, given their association with in-hospital mortality.
Department of Health Sciences, University of Milano Bicocca, Italy; Acute Geriatric Unit, San Gerardo Hospital, Monza, Italy; Milan Center for Neuroscience (Neuro-Mi), Milan, Italy. Electronic address: giuseppe.bellelli@unimib.it.
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Bellelli
Department of Neuroscience, IRCCS Istituto di Ricerche Farmacologiche "Mario Negri", Milano, Italy.
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Nobili
Department of Health Sciences, University of Milano Bicocca, Italy; Acute Geriatric Unit, San Gerardo Hospital, Monza, Italy; Milan Center for Neuroscience (Neuro-Mi), Milan, Italy.
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Annoni
Department of Rehabilitation and Aged Care, Hospital Ancelle, Cremona, Italy; Geriatric Research Group, Brescia, Italy.
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Morandi
Department of Neuroscience, IRCCS Istituto di Ricerche Farmacologiche "Mario Negri", Milano, Italy.
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Djade
Graduate Entry Medical School, University of Limerick, Ireland; Cognitive Impairment Research Group, Centre for Interventions in Infection, Inflammation & Immunity (4i), Graduate Entry Medical School, University of Limerick, Ireland; Department of Psychiatry, University Hospital Limerick, Ireland.
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Meagher
Edinburgh Delirium Research Group, Geriatric Medicine, Division of Health Sciences, School of Clinical Sciences, University of Edinburgh, Edinburgh, Scotland, United Kingdom; Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Scotland, United Kingdom.
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Maclullich
MRC Unit for Lifelong Health and Ageing, University College London, United Kingdom.
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Davis
Department of Health Sciences, University of Milano Bicocca, Italy.
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Mazzone
Department of Neuroscience, IRCCS Istituto di Ricerche Farmacologiche "Mario Negri", Milano, Italy.
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Tettamanti
Scientific Direction, IRCCS Ca' Granda Maggiore Policlinico Hospital Foundation, Milano, Italy.
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Mannucci
D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D003071:Cognition; D003693:Delirium / Q000175:diagnosis* / Q000453:epidemiology*; D005260:Female; D007722:Health Knowledge, Attitudes, Practice; D017052:Hospital Mortality; D006760:Hospitalization; D006801:Humans; D007558:Italy; D016015:Logistic Models; D008297:Male; D015999:Multivariate Analysis; D011446:Prospective Studies; D011569:Psychiatric Status Rating Scales; D012307:Risk Factors
Acute medical wards; Delirium; Neurocognitive deficits; Older; Under-detection