Validation of the New Interpretive Guidelines for the Clinical Dementia Rating Scale Sum of Boxes Score in the National Alzheimer's Coordinating Center Database

Abstract

Background: It was recently demonstrated that the Clinical Dementia Rating scale Sum of Boxes (CDR-SB) score can be used to accurately stage severity of Alzheimer dementia and mild cognitive impairment (MCI). However, to our knowledge, the utility of those interpretive guidelines has not been cross-validated or applied to a heterogeneous sample of dementia cases.Objective: To cross-validate the staging guidelines proposed in a previous study using the National Alzheimer's Coordinating Center (NACC) database. Design:The previously published cut scores were applied to the NACC sample and diagnostic accuracy estimates obtained. Next, analyses were restricted to NACC participants with a CDR global score (CDR-GS) of 0.5 and receiver operating characteristic curves generated to determine optimal CDR-SB cut scores for distinguishing MCI from very early dementia. Setting:The 2008 NACC uniform data set.Participants: There were 12 462 participants (5115 controls; 2551 patients with MCI; 4796 patients with de-mentia, all etiologies) in the NACC data set used for the current analysis.Main Outcome Measure: Accurate prediction of diagnoses (MCI or dementia) using the CDR-SB score. Results:The previously proposed CDR-SB ranges successfully classified the vast majority of patients across all impairment ranges with a of 0.91 and 94% overall correct classification rate. Additionally, the CDR-SB score discriminated between patients diagnosed with MCI and dementia when CDR-GS was restricted to 0.5 (overall area under the curve=0.83).Conclusions: These findings cross-validate the previously published CDR-SB interpretative guidelines for staging dementia severity and extend those findings to a large heterogeneous sample of patients with dementia. Additionally, the CDR-SB scores distinguished MCI from dementia in patients with reasonable accuracy when CDR-GS was restricted to 0.5.

Can the Clinical Dementia Rating Scale Identify Mild Cognitive Impairment and Predict Cognitive and Functional Decline?

“…The findings with respect to the CDR-GS are consistent with a large body of literature [1,[13][14][15][16][17][18][19] . However, the findings with respect to the CDR-SOB scores are inconsistent with previous studies in which CDR-SOB scores of 0.5-4.0 accurately represented MCI individuals [9,21] . One explanation for this discrepancy could be the way in which MCI was defined.…”

“…abnormal performance on at least two tests within a domain, the CDR-SOB score distinguished well between MCI and cognitively 'normal' individuals. It is noteworthy that the mean SOB score in our sample was 0.39 (SD = 0.57) for individuals with broadly defined MCI and 0.63 (SD = 0.6) for individuals with narrowly defined MCI compared to 1.5 (SD = 1.1) and 1.3 (SD = 1.2) for the MCI cohorts reported by O'Bryant et al [9,21] , respectively, which may also account for the discrepancy.…”

Can the Clinical Dementia Rating Scale Identify Mild Cognitive Impairment and Predict Cognitive and Functional Decline?

“…The findings with respect to the CDR-GS are consistent with a large body of literature [1,[13][14][15][16][17][18][19] . However, the findings with respect to the CDR-SOB scores are inconsistent with previous studies in which CDR-SOB scores of 0.5-4.0 accurately represented MCI individuals [9,21] . One explanation for this discrepancy could be the way in which MCI was defined.…”

“…abnormal performance on at least two tests within a domain, the CDR-SOB score distinguished well between MCI and cognitively 'normal' individuals. It is noteworthy that the mean SOB score in our sample was 0.39 (SD = 0.57) for individuals with broadly defined MCI and 0.63 (SD = 0.6) for individuals with narrowly defined MCI compared to 1.5 (SD = 1.1) and 1.3 (SD = 1.2) for the MCI cohorts reported by O'Bryant et al [9,21] , respectively, which may also account for the discrepancy.…”

Targeted Mass Spectrometry Suggests Beta-Synuclein as Synaptic Blood Marker in Alzheimer’s Disease

“…We divided the AD group of the Ulm cohort into MCI-AD (CDR-SB < 2.5) and demented AD patients (CDR-SB ≥ 2.5) . CSF βSyn was already significantly increased in MCI-AD patients ( p < 0.01) and also in AD dementia ( p < 0.001) compared with controls (Figure A).…”

Affliction class moderates the impact of neurodegeneration: Implications for A/T/N

“…The N factor explains variance in CDR-SB independently of competing dementia risks ( Table 2 ). As expected, CR and the N Factor together explain 100% of dTEL's variance (by multivariate regression: F (2, 1928) = 496E, 15 p < 0.001. R²=1.00.…”

Can the Clinical Dementia Rating Scale Identify Mild Cognitive Impairment and Predict Cognitive and Functional Decline?

“…The findings with respect to the CDR-GS are consistent with a large body of literature [1,[13][14][15][16][17][18][19] . However, the findings with respect to the CDR-SOB scores are inconsistent with previous studies in which CDR-SOB scores of 0.5-4.0 accurately represented MCI individuals [9,21] . One explanation for this discrepancy could be the way in which MCI was defined.…”

“…abnormal performance on at least two tests within a domain, the CDR-SOB score distinguished well between MCI and cognitively 'normal' individuals. It is noteworthy that the mean SOB score in our sample was 0.39 (SD = 0.57) for individuals with broadly defined MCI and 0.63 (SD = 0.6) for individuals with narrowly defined MCI compared to 1.5 (SD = 1.1) and 1.3 (SD = 1.2) for the MCI cohorts reported by O'Bryant et al [9,21] , respectively, which may also account for the discrepancy.…”

Targeted Mass Spectrometry Suggests Beta-Synuclein as Synaptic Blood Marker in Alzheimer’s Disease

“…We divided the AD group of the Ulm cohort into MCI-AD (CDR-SB < 2.5) and demented AD patients (CDR-SB ≥ 2.5) . CSF βSyn was already significantly increased in MCI-AD patients ( p < 0.01) and also in AD dementia ( p < 0.001) compared with controls (Figure A).…”

Affliction class moderates the impact of neurodegeneration: Implications for A/T/N

“…The N factor explains variance in CDR-SB independently of competing dementia risks ( Table 2 ). As expected, CR and the N Factor together explain 100% of dTEL's variance (by multivariate regression: F (2, 1928) = 496E, 15 p < 0.001. R²=1.00.…”

Can the Clinical Dementia Rating Scale Identify Mild Cognitive Impairment and Predict Cognitive and Functional Decline?

“…The findings with respect to the CDR-GS are consistent with a large body of literature [1,[13][14][15][16][17][18][19] . However, the findings with respect to the CDR-SOB scores are inconsistent with previous studies in which CDR-SOB scores of 0.5-4.0 accurately represented MCI individuals [9,21] . One explanation for this discrepancy could be the way in which MCI was defined.…”

“…abnormal performance on at least two tests within a domain, the CDR-SOB score distinguished well between MCI and cognitively 'normal' individuals. It is noteworthy that the mean SOB score in our sample was 0.39 (SD = 0.57) for individuals with broadly defined MCI and 0.63 (SD = 0.6) for individuals with narrowly defined MCI compared to 1.5 (SD = 1.1) and 1.3 (SD = 1.2) for the MCI cohorts reported by O'Bryant et al [9,21] , respectively, which may also account for the discrepancy.…”

Targeted Mass Spectrometry Suggests Beta-Synuclein as Synaptic Blood Marker in Alzheimer’s Disease

“…We divided the AD group of the Ulm cohort into MCI-AD (CDR-SB < 2.5) and demented AD patients (CDR-SB ≥ 2.5) . CSF βSyn was already significantly increased in MCI-AD patients ( p < 0.01) and also in AD dementia ( p < 0.001) compared with controls (Figure A).…”

Affliction class moderates the impact of neurodegeneration: Implications for A/T/N

“…The N factor explains variance in CDR-SB independently of competing dementia risks ( Table 2 ). As expected, CR and the N Factor together explain 100% of dTEL's variance (by multivariate regression: F (2, 1928) = 496E, 15 p < 0.001. R²=1.00.…”