Background and purpose: Memory deficit is a common sign of Alzheimer's disease (AD), which appeared generally in the early stage of the disease. Therefore, evaluation of memory is important for management of patients and for clinical research of AD. The Short-Memory Questionnaire (SMQ), an easily administered, informant-based scale, which was developed by Koss et al. (1993), is a standardized, validated, and reliable tool to assess everyday memory problems. In the present study, we prepared a Japanese version of the SMQ and examined its reliability and validity in assessing AD patients.
Subjects and methods: The subjects consisted of 42 patients with NINCDS-ADRDA probable AD whose diagnosis was made on the basis of the results of comprehensive examinations including cranial CT/MRI and SPECT and age- and education-matched 53 healthy controls. Patients had no history of stroke, head injury, or any other prior neurological events. Patients and controls were between the ages of 51 and 90 years, and they had from 6 to 16 years education. The Japanese version of the SMQ was given to a family member by either neuropsychiatrist, public nurse or case worker. To evaluate test-retest reliability of the test, interview was repeated in 16 randomly selected patients by two different examiners (neuropsychiatrist and another) in two weeks interval. The Mini-Mental State Examination (MMSE) was used to assess the severity of cognitive impairment.
Result: The test-retest reliability was acceptably high with intraclass correlation coefficients. There was a high correlation between scores of SMQ and MMSE. The SMQ had excellent specificity and sensitivity in discriminating patients from controls. Caregiver appraisals of memory deficits significantly correlated with generalized cognitive dysfunction.
Conclusions: Similarly to the original version, the present Japanese version of the SMQ is a reliable and valid tool in assessing memory function in AD, which can be effectively used in clinical settings and epidemiologic studies to screen out persons with memory problems.