AD8 Informant Questionnaire for Cognitive Impairment

Abstract

The diagnostic accuracy of the AD8 informant questionnaire for cognitive impairment was assessed in patients referred to a dedicated memory clinic. This pragmatic prospective study of consecutive referrals attending with an informant who completed AD8 (n = 212) lasted 12 months. Diagnosis used standard clinical diagnostic criteria for dementia and mild cognitive impairment as reference standard (prevalence of cognitive impairment = 0.62). The AD8 proved acceptable to informants, was quick, and easy to use. Using the cutoff of ≥2/8, AD8 was highly sensitive (0.97) for diagnosis of cognitive impairment but specificity was poor (0.17). Combining AD8 with either the Mini-Mental State Examination or the Six-Item Cognitive Impairment Test showed little additional diagnostic benefit. In conclusion, AD8 is very sensitive for cognitive impairment in a memory clinic but specificity may be inadequate.

Zarit Burden Interview: pragmatic study in a dedicated cognitive function clinic

“…Informants were thus predominantly female (69%), as in a previous non-overlapping cohort seen in this clinic (74%). 18 Final patient diagnoses were dementia (n=16), MCI (15), and subjective memory complaint (SMC; 14).…”

“…Unsurprisingly, in view of the large score range for each diagnostic group, ZBI lacks utility as an informant-based cognitive screening instrument, 20 unlike other informant-based scales such as the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) 21,22 and the AD8. 18,23 The ineluctable corollary of this obser vation is that inferences about caregiver burden cannot be based on patient cognitive scores, and must therefore be assessed independently in each case. In other words, ZBI has pragmatic use as an instrument for the identification and quantification of caregiver burden at initial diagnostic assessment of patients with cognitive complaints, and may therefore be used to plan appropriate caregiver inter ventions independent of patient diagnosis.…”

Diagnostic test accuracy of cognitive screeners in older people

“…The datasets from several pragmatic prospective diagnostic test accuracy studies undertaken in the authors' clinic were used, [4][5][6][7][8][9] All studies followed a similar protocol.…”

Cognitive screening instruments for the diagnosis of mild cognitive impairment

“…44 Another avenue for future study would be combining performancebased and informant-based CSIs. This has been attempted for diagnosis of dementia (MMSE and AD8; 6CIT and AD8), 25 with improved sensitivity for MMSE and AD8 in the parallel ('Or' rule) paradigm.…”

“…24 Where appropriate, data from pragmatic studies of informant-based screeni n g i n s t r u m e n t s w e r e a l s o included, 25,26 specifically AD8, 27 and the short and screening versions of the Zarit Burden Interview (ZBI), 28,29 which has been examined as a possible informant-based CSI. 26 Study details (setting, sample size, prevalence of dementia and MCI in the case mix, sex ratio, age range) are shown in Table 1.…”