Aim: We aimed to evaluate the psychometric properties of the Subjective Memory Complaints Questionnaire (SMCQ).
Methods: The reliability of the SMCQ was evaluated by testing its internal consistency and test-retest reliability. Pearson correlation analyses were performed to assess the concurrent validity. Confirmatory factor analysis was used to evaluate the construct validity. Diagnostic ability for dementia was tested with receiver operator characteristic curve analyses.
Results: Cronbach's alpha coefficient and intraclass correlation coefficients of the SMCQ were 0.864 and 0.828 (p < 0.001), respectively. The SMCQ scores were significantly correlated with the scores on Camdex Memory Complaint Questionnaire, Seoul Informant Report Questionnaire for Dementia and cognitive tests from the CERAD (Consortium to Establish a Registry for Alzheimer's Disease) neuropsychological test battery (p < 0.01). The results of confirmatory factor analyses confirmed that the SMCQ consisted of subjective memory complaints (SMC) for general memory and for everyday memory. The SMCQ score discriminated well between nondemented elderly without dementia and those with dementia (p < 0.01). The area under the curve value of the SMCQ was 0.84, indicating that it had high diagnostic ability.
Conclusion: The SMCQ was found to be a brief, reliable and valid questionnaire for evaluating SMC. It might be useful for evaluating the cognition of elderly subjects when reliable informants are not available.