J Korean Neurol Assoc.  1998 Jun;16(3):307-314.

The validity and reliability of the Samsung Dementia Questionnaire (SDQ)

• Choi SH
• Na DL
• Kang Y
• Lee WY
• Park BJ

Abstract

BACKGROUND AND PURPOSE: The Samsung Dementia Questionnaire (SDQ) was developed to screen dementia by asking an informant about an elderly person's everyday cognitive function. We conducted a case-control study to determine the effects of socio-demographic variables on the SDQ, and the validity and reliability of the SDQ for the diagnosis of dementia.
METHODS
The questionnaire was administered to informants of 54 dementia patients (35 Alzheimer's disease, 19 vascular dementia) and 63 hospital control subjects. Frequency matching was done about age, sex and residence between the two groups. Informants were limited to intimate family member living with the subject. Test-retest data for the SDQ were obtained from 17 informants within a time interval averaging 31.12 days.
RESULTS
The SDQ was not influenced by education level, age, or sex. Scores from the SDQ were found to correlate with the K-MMSE (r=-0.80). The area under the receiver operating characteristic (ROC) curve for the SDQ was 0.977 (S. E.=0.099). With respect to a diagnosis of dementia, the SDQ (cut-off point 17) had a sensitivity of 89% and a specificity of 94%. The SDQ was found to have high test-retest reliability (r=0.98).
CONCLUSION
The SDQ has high validity and test-retest reliability for the diagnosis of Alzheimer's disease and vascular dementia. It may be a useful tool for screening dementia.

Keyword

Questionnaire; Dementia; Screening; Alzheimer disease; vascular dementia

MeSH Terms

Aged
Alzheimer Disease
Case-Control Studies
Dementia*
Dementia, Vascular
Diagnosis
Education
Humans
Mass Screening
Surveys and Questionnaires*
Reproducibility of Results*
ROC Curve
Sensitivity and Specificity