Linking the Clinical Dementia Rating Scale-Sum of Boxes, the Clinician’s Interview-Based Impression Plus Caregiver Input, and the Clinical Global Impression Scale: Evidence based on Individual Participant Data from Five Randomized Clinical Trials of Donepezil

Background: In patients with Alzheimer’s disease, global assessment scales, such as the Clinical Dementia Rating-Sum of Boxes (CDR-SB), Clinician’s Interview-Based Impression Plus Caregiver Input (CIBI plus), and Global (CGI) are commonly used. Objective: To clinically understand interpret associations between these we examined linkages for total change scores CDR-SB, CIBI plus, CGI. Methods: Individual participant data (N = 2,198) from five pivotal randomized placebo-controlled trials donepezil were included. Data collected at baseline scheduled visits up to 6 months. Spearman’s correlation coefficients ρ corresponding simultaneous CGI ratings. link ratings, equipercentile linking was Results: We found strong evidence that CDR-SB CGI, plus least adequately correlated (ρ= 0.50 0.71, p < 0.01). The deemed adequate weeks 24 0.44 0.65); remaining correlations smaller in magnitude 0.09 0.35). Overall, in-line expectations, e.g., range score 3-4 (= very mild dementia) linked a 3 mildly ill), an increase 1 5 minimal worsening) both plus. Conclusion: study findings can be useful clinicians wishing compare different scales across patients. They also help researchers results studies using facilitate meta-analyses, statistical power.