Reliability and construct validity of the Early Dementia Questionnaire (EDQ)

Abstract

BackgroundEarly Dementia Questionnaire (EDQ) was developed as a screening tool to detect patients with early dementia in primary care. It was developed based on 20 symptoms of dementia. From a preliminary study, EDQ had been shown to be a promising alternative for screening of early dementia. This study was done to further test on EDQ’s reliability and validity.MethodsUsing a systematic random sampling, 200 elderly patients attending primary health care centers in Kuching, Sarawak had consented to participate in the study and were administered the EDQ. Geriatric Depression Scale (GDS) was used to exclude patients with depression. Those who scored >21 MMSE, were retested using the EDQ. Reliability was determined by Cronbach’s alpha for internal consistency and construct validity was assessed using confirmatory factor analysis (principle component with varimax rotation). Test retest Intraclass Correlation Coeeficient (ICC) was used to determine the reliability of the scale.ResultsThe result showed that the sensitivity and specificity for EDQ was 71.2% and 59.5%. The overall Cronbach’s alpha coefficient was good which was 0.874. Confirmatory factor analysis on 4 factors indicated that the Cronbach’s alpha for each domain were acceptable with memory (0.741), concentration (0.764), emotional and physical symptoms (0.754) and lastly sleep and environment (0.720). The Intraclass Correlation Coefficient between the first EDQ score and the retest EDQ score among those with MMSE of >21 showed a very strong overall agreement, ICC = 0.764, N = 160, P <0.001.ConclusionsThe results of the validation study showed that Early Dementia Questionnaire (EDQ) is a valid and reliable tool to be used as a screening tool to detect early dementia in primary care.

Current approaches to dementia screening and case finding in low‐ and middle‐income countries: Research update and recommendations

“…To address concerns associated with cultural, literacy, and educational bias, several new cognitive instruments have been specifically developed and validated in different LMICs from the Middle East, Africa, and South‐East Asia including (1) The Dementia Screening Battery 100 (DES‐100, Tunisia), (2) The NIMHANS Neuropsychological Battery for Elderly (NNB‐E, India), (3) The Dementia Assessment by Rapid Test (DART, India), (4) The Cognitive State Test (COST, Turkey), (5) The Identification and Intervention for Dementia in Elderly Africans (IDEA, Sub‐Saharan Africa including Tanzania and Nigeria), and (6) The Early Dementia Questionnaire (EDQ, Malaysia) . Some of the domains assessed by these tests include orientation, memory, language, concentration, verbal fluency, attention, executive function, and praxis.…”

“…Findings from the development/validation studies of these measures do not yet clearly suggest that they are more adequate compared with adapted versions of tools from HICs such as the MMSE. In some instances, adapted versions of the MMSE had better discriminant validity (eg, the DART India and EDQ Malaysia had lower specificity than the MMSE) . Therefore, while these new measures are promising, their properties, applicability, and discriminative accuracy (ie, cut‐off scores) need to be further evaluated using local representative cohorts across different LMICs to ensure generalizability and usability.…”

“…(3) The Dementia Assessment by Rapid Test (DART, India),39 (4) The Cognitive State Test (COST, Turkey),40 (5) The Identification and Intervention for Dementia in Elderly Africans (IDEA, Sub-Saharan Africa including Tanzania and Nigeria),41 and(6)The Early Dementia Questionnaire (EDQ, Malaysia) 42. Some of the domains assessed by these tests include orientation, memory, language, concentration, verbal fluency, attention, executive function, and praxis.…”

A systematic review and meta-analysis of studies on screening for mild cognitive impairment in primary healthcare

“…As an index test, all studies used short tools to diagnose cognitive disorders. MMSE were used in 14 studies [ 18 – 23 , 25 – 30 , 32 – 34 , 38 ], General Practitioner Assessment of Cognition (GPCOG) in two studies [ 18 , 26 ], Test Your Memory (TYM) in two study [ 26 , 29 ], Early Dementia Questionnaire (EDQ) in two studies [ 32 , 33 ], Ascertain Dementia 8-item (AD8) in one study [ 30 ], the Informant Questionnaire On Cognitive Decline in the Elderly (IQCODE) in one study [ 37 ], the Picture version of the Free and Cued Selective Reminding Test with Immediate Recall (pFCSRT + IR) in two studies [ 36 , 38 ], Malay Version Rowland Universal Dementia Assessment Scale (M-RUDAS) in one study [ 24 ], a new screening method to support diagnosis of dementia (DemTect) in one study [ 34 ], and the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) in one study [ 27 ]. Also, as a reference test, 10 studies have used the agreement of psychiatrists or geriatricians [ 20 , 21 , 23 , 25 , 27 , 28 , 31 , 35 – 37 ], one study [ 19 ] used CAMCOG, eight studies used MMSE [ 20 , 24 , 26 , 29 , 30 , 33 , 34 , 37 ] and two studies used MOCA [ 19 , 30 ] (Table 1 ).…”

“…The accuracy of EDQ diagnosis and its comparison with MMSE has been studied in two studies [ 32 , 33 ]. In these studies, the sensitivity for EDQ was (0.669, 0.799) and the specificity was (0.477, 0.651).…”