Informant Presence Fails to Enhance Alzheimer's Diagnosis in Complex Veteran Cases

Informant reports are thought helpful for Alzheimer's disease (AD) diagnosis. We hypothesized that informants would improve diagnostic accuracy, operationalized as agreement between clinical impression and amyloid PET (aPET) findings.

This study was a retrospective analysis of 168 Veterans referred for aPET due to diagnostic uncertainty or atypical presentation (Mage=69.3, SD=5.8). We examined the association between diagnostic accuracy and presence of an informant, patient's MoCA score, and informant type.

We found no evidence that informant presence was associated with diagnostic accuracy (OR = 0.92, 95% CI 0.48, 1.72), that this association varied by patient cognitive status as measured by MoCA (interaction OR = 1.13, 95% CI 0.97, 1.33), or that diagnostic accuracy differed by informant type (spouse/partner: OR = 1.23, 95% CI 0.55, 2.79; other: OR = 0.91, 95% CI 0.29, 2.71).

Our findings suggest informant presence does not necessarily enhance diagnostic accuracy for complex AD presentations. This highlights the continued value of aPET imaging in complex clinical presentations.