Development of the Subjective Cognitive Decline Scale for Mandarin-Speaking Population.

Subjective cognitive decline (SCD) has been considered a high-risk group preceding mild cognitive impairment (MCI). However, methods to quantify and track the complaints have not been well-established. The present study aimed to develop a questionnaire tailored for Mandarin-speaking individuals with SCD. A total of 175 adults aged above 55 years completed a comprehensive set of items evaluating cognitive problems and neuropsychological examinations. After item reduction, internal consistency, construct, and concurrent validity were examined. The 14-item Subjective Cognitive Decline Scale (SCDS) has acceptable internal consistency (Cronbach's α = .93) and construct validity with a three-factor structure. Individuals with SCD and MCI scored higher than the control group. The SCDS demonstrated significant but small correlations with multiple cognitive tests and emotional variables. The SCDS provides an alternative approach to measure cognitive complaints, while an influence of emotional status shall be taken into consideration when interpreting the results.