Dementia and Related Comorbidity: Analysis of 2 Years of Admissions to Italian Hospitals

Background: The aim of the present study was to examine the prevalence of dementia, related comorbidities, and mortality rates in hospitalized elderly patients in Italy. Methods: Data were obtained from the Italian Ministry of Health and included all discharge records from Italian hospitals concerning subjects aged 65 years or above admitted to acute Internal Medicine during 2 years (n=3,695,278 admissions). Discharge diagnoses were re-classified into 24 clusters, each including homogeneous diseases by the ICD-9-CM code classification. Dementia was identified by the presence of ICD-9-CM codes 290, 294, or 331 series. Results: Patients with dementia represented 7.5% of the sample; compared with those without dementia, they were older and more often female, had a greater length of hospital stay and higher mortality rate. Besides delirium [odds ratio (OR): 54.20], enthesopaties (OR: 2.19), diseases of fluids and electrolytes (OR:1.96), diseases of arteries (OR: 1.69), skin diseases (OR: 1.64), and pneumonia and pleurisy (OR: 1.53) were the diseases more strongly associated with the diagnosis of dementia, independent of other clusters, age, sex, and length of stay. Conclusions: Some comorbidities are specifically associated with the diagnosis of dementia among hospitalized elderly patients. Overall, these comorbidities describe the typical clinical profile of the patient with advanced dementia and could be treated in the context of the primary care, since they do not require specific skills belonging to hospital settings.