The Diagnosis of Dementia: Diagnostic Accuracy of an Instrument Measuring Activities of Daily Living in a Clinic-Based Population

Abstract

Background/Aims: Since widely accepted definitions of dementia encompass impairments in social and occupational, as well as cognitive, function, we investigated the diagnostic accuracy of Lawton and Brody’s Instrumental Activities of Daily Living (IADL) Scale as an independent test for the diagnosis of dementia. Methods: The IADL Scale was administered to consecutive referrals to 2 memory clinics over a 2-year period, independent of other tests (interview, neuropsychology, imaging) which were used to establish diagnoses according to standard diagnostic criteria, and the results were compared. Results: In a cohort of 296 patients, 52% adjudged to have dementia, IADL Scale scores and subscores showed low sensitivity, specificity, and positive and negative predictive values for the diagnosis of dementia. The likelihood ratios, a measure of diagnostic gain, were generally small to unimportant, and diagnostic accuracy as measured by area under the receiver operating characteristic curve was no better than 0.75. Conclusion: IADL Scale scores are not very helpful in making a diagnosis of dementia. More sensitive scales may be required to detect dementia-related functional decline, although it is also possible that dementia syndromes may be present in the absence of functional decline, challenging accepted definitions of dementia.

Clinical utility of Patient Health Questionnaire-9 (PHQ-9) in memory clinics

“…Of these, 49 (43%) were judged to be demented by DSM-IV criteria and 64 (57%) not demented, a frequency for dementia prevalence similar to that recorded in a previous, nonoverlapping, patient cohort from these clinics [13].…”

Test Your Memory test: diagnostic utility in a memory clinic population

“…Standard clinical diagnostic criteria were used for the diagnosis of dementia (DSM-IV; American Psychiatric Association, 2000) and dementia subtypes (McKhann et al, 1984(McKhann et al, , 2001Román et al, 1993;McKeith et al, 1996McKeith et al, , 1999Neary et al, 1998;Petersen et al, 1999), as in previous collaborative studies between these units (Hancock and Larner, 2007, 2008, 2009a, 2009b, 2009cLarner and Hancock, 2008). As this was a pragmatic study, patients were not selected according to diagnosis but as they presented to the clinics.…”

Cambridge Behavioural Inventory for the diagnosis of dementia

“…8 Dementia subtypes and mild cognitive impairment were defined using widelyaccepted diagnostic criteria, as in our previous collaborative studies. 9 CBI administration was performed independent of, but on the same day as, patient clinical and neuropsychological assessment but was not used in the diagnostic judgment of dementia/no dementia or dementia subtype in order to minimise review bias. 10 Inevitably, there was some overlap in the information obtained by the clinician through informant inter view and that obtained from the CBI.…”