Delirium Index Six-Monthly in Patients with Dementia, Mild Cognitive Impairment and Subjective Cognitive Impairment: Keys to Interpreting Delirium Index in Cognitive Impairment

Abstract

Background: The delirium index (DI) is a simple non-copyrighted test which captures most delirium symptoms and signs. Despite its attractiveness it has been used in only 21/589 (3.6%) delirium articles published after DI appeared.

Methods: Prospective observational cohort study in a geriatric memory clinic. We followed 259 community-dwelling elderly with dementia, mild cognitive impairment (MCI) and subjective cognitive impairment (SCI). Measurements: six-monthly DI, Mini-Mental State (MMSE), Montreal Cognitive Assessment (MoCA), Addenbrooke Cognitive Assessment (ACE-R), Frontal Assessment Battery (FAB) to predict the declines in instrumental activities of daily living (IADL). Mean follow-up was 622 days.

Results: Mean DI increased from baseline 3.20 ± 1.90, to six-month 3.41 ± 2.00, twelve-month 3.61 ± 2.13, and peaked at eighteen-month 4.10 ± 2.2. It then declined to 3.71 ± 2.43 at twenty-four months, 3.98 ± 2.24 at thirty months. Spearman rank correlations were significant at a P < 0.0001 level between baseline DI and baseline and six-month IADL, MMSE, MoCA, ACE-R, FAB and with later DI at six, twelve, eighteen, twenty-four, thirty and thirty-six months. Comparing 227/259 patients with baseline DI 0 - 5 to 32/259 with baseline DI ≥ 6, the two groups differed significantly in baseline IADL (22% difference between means of the two groups, P = 0.004), baseline MMSE (35%, P < 0.001), baseline MoCA (48%, P < 0.001), baseline FAB (41%, P < 0.001), and baseline ACE-R (36%, P < 0.0001).

Conclusions: Mean delirium index increased progressively every six months to eighteen months in a memory clinic. DI is a good tool to monitor elderly at risk for delirium.




J Neurol Res. 2013;3(3-4):96-100
doi: https://doi.org/10.4021/jnr204e