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

Area of Science:

• Geriatric Medicine
• Neurology
• Psychometry

Background:

• The Early Dementia Questionnaire (EDQ) was developed to screen for early dementia in primary care.
• It is based on 20 dementia-related symptoms and showed promise in preliminary studies.
• This research aimed to further validate the EDQ's reliability and diagnostic accuracy.

Purpose of the Study:

• To assess the reliability and validity of the Early Dementia Questionnaire (EDQ) as a screening tool for early dementia.
• To determine the sensitivity and specificity of the EDQ in a primary care population.
• To evaluate the internal consistency and test-retest reliability of the EDQ.

Main Methods:

• A systematic random sample of 200 elderly patients in primary care centers participated.
• The Geriatric Depression Scale (GDS) was used to exclude patients with depression.
• Reliability was assessed using Cronbach's alpha and test-retest Intraclass Correlation Coefficient (ICC). Construct validity was evaluated via confirmatory factor analysis.

Main Results:

• The EDQ demonstrated a sensitivity of 71.2% and specificity of 59.5%.
• Excellent internal consistency was found with an overall Cronbach's alpha of 0.874.
• Test-retest reliability was very strong, with an ICC of 0.764 (P <0.001).

Conclusions:

• The Early Dementia Questionnaire (EDQ) is a valid and reliable instrument for screening early dementia in primary care.
• The EDQ's psychometric properties support its use in clinical settings for early detection.
• Further research may explore its utility across diverse populations and healthcare levels.