Reliability of the assessment of the clinical dementia rating scale from the analysis of medical records in comparison with the reference method

Abstract

Abstract Background The Clinical Dementia Rating (CDR) scale allows to detect the presence of dementia and to assess its severity, however its evaluation requires a significant time (45 min). We evaluated the agreement between two methods of collection of the CDR: face-to-face interview or based on the information available in the patient’s medical record. Methods The CLIMER study was conducted among patients attending a memory center. The CDR scale was evaluated during face-to-face interviews between neuropsychologists and patients and their caregivers and based on blind analysis of the information of the patients’ medical record by neuropsychologists. The agreement of the CDR sum of boxes (CDR-SB), the 5-point scale CDR and the different domains of the CDR evaluated between the different methods was measured using intraclass correlation (ICC) coefficient, Bland and Altman method, and linearly weighted Kappa. Results The study included 139 patients (means ± SD age 80.1 ± 6, 58.3% women, 71.9% with dementia). The ICC for the CDR-SB score assessed by face-to-face and with all the information available in the patient’s medical record was 0.95 (95% CI: 0.93–0.97). The mean difference between the CDR-SB score assessed by face-to-face and with the medical record was 0.098 ± 1.036, and 92.4% of the patients lay within the 95% limits of agreement. The ICC for the 5-point scale CDR assessed by face-to-face and with the patient’s medical record was 0.92 (95% CI: 0.88–0.95) when all the available information of the patient’s medical record was used. The linear weighted Kappa coefficients was 0.79 (95% CI: 0.68–0.91) for the 5-point scale CDR comparison between the two evaluation methods. The analysis by domain of the CDR showed ICC ranging from 0.65 to 0.91 depending of the domains and the methods of evaluation. Conclusion This study showed an excellent level of agreement of the evaluation of the CDR- SB and the 5-point scale CDR when using all the information of the patient’s medical record compared to the face-to-face interview. Trial registration https//clinicaltrials.gov/ct2/show/NCT04763941 Registration Date 02/17/2021.

Keywords

• Clinical dementia rating
• Alzheimer’s disease
• Reliability
• Neuropsychology
• Neurocognitive disorders