B – 1 Whose Reality? Comparing Patient, Caregiver, and Objective Assessments of Cognition in Brain Tumor Patients

Abstract Objective Cognitive deficits are common in individuals with primary brain tumors and often impact caregivers who support patients when cognitive abilities decline. This secondary analysis examined associations between patient-caregiver agreement on patient subjective cognition and objective cognitive performance in dyads enrolled in C-SMART (Cognitive Strategies, Mindfulness, and Rehabilitation Therapy). Method Patients with primary brain tumors (N=15, Mage=55.6, 40% female) and their caregivers (N=15, Mage=56.6, 73% female, 80% spouse) completed eight 1-hour C-SMART sessions. At baseline and post-intervention, patients completed neurocognitive testing based on the International Cancer and Cognition Task Force battery, and patients and caregivers completed the Functional Assessment of Cancer Treatment-Brain – Cognitive Index. Paired t-tests compared patient and caregiver reports. Lin’s concordance correlation coefficient (CCC) assessed patient-caregiver agreement. Pearson correlations examined associations between subjective and objective cognition. Result: Patient and caregiver reports of patient cognition did not differ at baseline (t(14)=.25, p=.80) or follow-up (t(11)=-.85, p=.41), showing moderate agreement (CCCs=.53 and .41). Subjective reports were only associated at baseline (r=.55, p=.03, Cohen’s d=.06). Post-C-SMART, patient-reported cognition was associated with delayed memory recognition (r=.65, p=.02). No correlations were found at baseline (ps.05). Caregiver report was not associated with patients’ objective performance at baseline or post-intervention (ps.05). Conclusion Patients and caregivers share a stable understanding of patient cognition, though correlations with objective measures were limited. Patient and caregiver reports may reflect functional changes, that are not adequately captured by objective tests. Findings underscore the distinction between subjective and objective cognition and the importance of measuring both when evaluating cognitive rehabilitation outcomes.