Development and Preliminary Psychometric Evaluation of the ACRIS-CS: A Theory-Based Measure of Prospective Acceptability of Cognitive Rehabilitation in Cancer Survivors

Background/Objectives: Cancer-related cognitive impairment (CRCI) is a prevalent survivorship concern associated with functional limitations and reduced quality of life. Although cognitive rehabilitation shows beneficial effects, implementation depends not only on efficacy but also on survivors’ anticipated willingness to engage. No psychometrically validated instrument currently exists to assess prospective acceptability of cognitive rehabilitation among cancer survivors. This study aimed to: (1) develop the Acceptability of Cognitive Rehabilitation Interventions Survey–Cancer Survivors (ACRIS-CS); (2) examine its structural validity (factor structure), internal consistency, and construct validity; (3) describe prospective acceptability levels; and (4) identify independent predictors. Methods: A cross-sectional study was conducted with 154 cancer survivors reporting cognitive complaints. The ACRIS-CS was developed based on the Theoretical Framework of Acceptability. Structural validity was examined using exploratory factor analysis (EFA); internal consistency was assessed with Cronbach’s alpha; and construct validity was evaluated through hypothesis-driven correlational analyses. Multiple linear regression was used to identify independent predictors of prospective acceptability. Results: EFA supported a three-factor structure explaining 68.7% of total variance (KMO = 0.847, Bartlett’s χ2 (55) = 864.431, p < 0.001). The total scale demonstrated good internal consistency (α = 0.85; subscales α = 0.73–0.85), and construct validity was supported. Mean prospective acceptability indicated overall moderate-to-high levels. Being in active treatment (β = −0.248, p = 0.001) and having greater prior knowledge of CRCI (β = 0.240, p = 0.002) were independently associated with prospective acceptability (adjusted R2 = 0.113). Conclusions: The ACRIS-CS demonstrated preliminary evidence of structural validity, internal consistency, and construct validity. Prospective acceptability appears to be influenced by treatment status and prior knowledge of CRCI, supporting the need for further confirmatory validation before routine clinical implementation.