The Clinical Dementia Rating Sum of Box Score in Mild Dementia

BACKGROUND: Making an early diagnosis of dementia is becoming increasingly important, but is difficult in practice. The Clinical Dementia Rating (CDR) scale is a widely used dementia staging instrument, yielding a global score and a summated score (sum of box score). This study examines the utility of the CDR sum of box score, rather than the CDR global score, in making a diagnosis of early dementia. OBJECTIVE: To determine whether the CDR sum of box score is predictive of an ICD-10 diagnosis of dementia in cases with mild cognitive deficits. METHODS: Clinical data recorded on our Memory Clinic database were examined for all patients seen over a 6-year period. Data were extracted from 276 first visits in which patients had scored 0.5 using the CDR global score. We examined the relationship between CDR sum of box score and consensus diagnosis of dementia using logistic regression. RESULTS: We found that increased CDR sum of box score was significantly associated with a higher probability of being assigned an ICD-10 diagnosis of dementia (p < 0.001). The odds ratio for the coefficient of CDR sum of box was 2.3 (95% CI 1.7-3.1), indicating that the likelihood of being diagnosed as having dementia increased by a factor of 2.3 for every point increase on the CDR sum of box score. CONCLUSION: These findings indicate that the CDR sum of box score provides additional information to the CDR global score in mild cases. The CDR sum of box score is a helpful indicator in making/excluding a diagnosis of dementia in people with mild cognitive deficits.