Influence of cognitive impairment and comorbidity on disability in hospitalized elderly patients

Abstract

Background: The effects of cognitive impairment and comorbidity on the prevalence of disability in elderly patients who are hospitalized in acute wards are not well defined.

Objectives: To evaluate the role of comorbidity and cognitive impairment on the prevalence of disability in a cohort of hospitalized older patients.

Patients and methods: This study included 179 patients aged 65 years and over admitted to the Geriatric Unit of the Casa Sollievo della Sofferenza Hospital, in Italy. Cognitive status was evaluated by means of the Mini Mental State Examination (MMSE) and Clinical Dementia Rating Scale (CDR); the functional status was evaluated according to the Activity of Daily Living (ADL) and Instrumental Activities of Daily Living (IADL) indices. Comorbidity was identified using the Cumulative Illness Rating Scale (CIRS index).

Results: Of the 179 patients enrolled 73 patients were diagnosed with dementia [Alzheimers' Disease (AD) = 49 patients, Vascular Dementia (VD) = 24 patients], 35 patients with Mild Cognitive Impairment (MCI) and 71 patients had no cognitive impairment. The severity of disability was significantly higher in patients with dementia (ADL = 3.1 +/- 2.1, IADL = 1.5 +/- 2.0) than patients with MCI (ADL = 5.1 +/- 1.4, IADL = 5.2 +/- 2.2) (p < 0.0001) and patients without cognitive impairment (ADL = 5.5 +/- 0.9, IADL = 6.4 +/- 1.9) (p < 0.0001). No significant differences in CIRS index were observed between patients with dementia and MCI and no cognitive impairment patients (Dementia = 2.4 +/- 1.4 vs MCI = 2.9 +/- 1.4 vs No cognitive impairment = 2.7 +/- 1.2; p = 0.1). Moreover, a significant correlation between cognitive impairment and functional status (MMSE/ADL: r = 0.45, p = 0.0001, MMSE/IADL: r = 0.54, p = 0.0001) but not between comorbidity and functional status (CIRS/ADL: r = 0.0007, CIRS/IADL: r = 0.040) was observed. Separating patients with dementia by diagnosis of AD or VD, no significant differences in MMSE (AD = 12.2 +/- 6.7 vs VD = 13.2 +/- 6.5, p = 0.6), CDR (AD = 2.2 +/- 0.8 vs VD = 2.1 +/- 0.7, p = 0.6), ADL (AD = 3.1 +/- 2.1 vs VD = 3.0 +/- 2.1, p = 0.8), IADL (AD = 1.3 +/- 1.9 vs VD = 2.0 +/- 2.2, p = 0.1) or CIRS (AD = 2.2 +/- 1.5 vs VD = 2.8 +/- 1.3, p = 0.06) scores were observed.

Conclusions: Cognitive impairment and not comorbidity, was significantly associated with disability in hospitalized older patients.