German Validation Study of the Subjective Cognitive Decline Questionnaire (SCD-Q)

Not Applicable

Recruiting

• Conditions: Alzheimer Disease; Subjective Cognitive Decline

• Registration Number: NCT06711952
• Lead Sponsor: Ludwig-Maximilians - University of Munich

Brief Summary

The SCD-Q (Subjective Cognitive Decline-Questionnaire) is an established instrument to quantify self-perceived cognitive decline. Both self- and informant-rated versions of the SCD-Q are available. However, the SCD-Q has not been validated in the German language yet. Hence, the investigators aim to validate the self-reported SCD-Q in a clinical sample in Germany.

Detailed Description

The SCD-Q is a well-established screening instrument to quantify perceived subjective cognitive decline. In addition to self-perceived cognitive complaints, a 24-item questionnaire for informants is part of the SCD-Q. It demonstrates high sensitivity and lower specificity for detecting dementia and early cognitive changes associated with dementia. However, the questionnaire has not been translated into German or validated. Plasma biomarkers for amyloid and tau pathology, as well as for neurodegeneration and astrocytic activation, have been developed and show promising sensitivity and specificity for detecting Alzheimer's disease (AD). A relevant proportion of biomarker-positive patients does not convert to mild cognitive impairment or Alzheimer's disease dementia during the disease course. Currently, the predictive value of blood biomarkers remains to be clarified, particularly in conjunction with SCD. This study aims to validate the SCD-Q in German and analyze possible connections with biomarkers and (digital) cognitive tests. Follow-up visits are planned.

Study Timeline

• Study Start: 2023-02-01
• Study First Submitted: 2023-12-21
• Study First Submitted QC: 2024-11-27
• Study First Posted: 2024-12-02
• Status Verified: 2025-05
• Last Update Submitted: 2025-05-22
• Last Update Posted: 2025-05-29
• Primary Completion: 2025-08-31
• Study Completion: 2025-08-31

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 300

Inclusion Criteria

• Medical appointment for dementia diagnostics at the Alzheimer Therapie- und Forschungszentrum
• Provision of signed, written and dated informed consent
• Capacity to give informed consent

Exclusion Criteria

• dementia in a very advance stage
• Illiteracy

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Primary Outcome Measures

Name	Time	Method
Validation of the SCD-Q in the german language	Baseline	assessment of its psychometric properties, including reliability, validity, and sensitivity/specificity, when translated into German.(neuropsychological test, neurological and psychiatric examination, MRI and optional lumbar puncture), sensitivity and specifity to identify participants with probable AD, establish cut-off values of the SCD-Q; • Internal consistency of the self-rated SCD-Q (measured by Cronbach's alpha).; * Test-retest reliability (correlation coefficient between repeated measures at two time points).; * Construct validity (comparison with related cognitive self-assessment tools or scales).; * Discriminative ability (sensitivity and specificity for distinguishing between individuals with subjective cognitive decline and those without, using ROC analysis).; * Linguistic validation process (forward and backward translation, followed by expert review and pilot testing).
combination of SCD-Q and biomarkers	Baseline	To determine and validate appropriate cut-off values for the self-rated SCD-Q for distinguishing between individuals with and without subjective cognitive decline. • Receiver Operating Characteristic (ROC) analysis to establish sensitivity and specificity of the SCD-Q.; * Optimal cut-off values derived using Youden's Index to maximize diagnostic performance.; * Units of Measure: SCD-Q total score (range: 0-100).
Correlation of SCD-Q with digital cognitive tests and a shortened version of SCD-Q	Baseline	correlation of the SCD-Q with a digital cognitive test and shortened version of the SCD-Q.

Trial Locations

Locations (1)

Klinik und Poliklinik für Psychiatrie und Psychotherapie des LMU Klinikums; 🇩🇪 München, Bayern, Germany