Adaptation, construct validity, and test-retest reliability of the Cognitive Reserve Index Questionnaire for the Israeli multiple sclerosis population.

Introduction: A common tool used to measure cognitive reserve is the Cognitive Reserve Index questionnaire (CRIq). In the present study, we aimed to adapt and determine the psychometric properties (validity and intra-rater test-retest reliability) of the Hebrew version of the CRIq in a cohort of people with multiple sclerosis (pwMS).

Methods: Fifty pwMS (30 women aged 48.3 (SD=10.2)) completed the CRIq and the Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS), which were used for validation. Secondary outcome measures included the evaluation of depression, anxiety, and perceived fatigue. Twenty-five (of the 50) pwMS were randomly selected and participated in the CRIq intra-rater test-retest reproducibility study based on a 7-12-day interval between tests.

Results: The mean CRIq total was 101.8 (S.D.=13.04), which is considered at the medium level. The CRIq section scores were at a similar medium level. According to Pearson's Rho correlation analysis, the CRIq total score and sections of education, work, and leisure were significantly correlated at a medium level (Rho ranging between 0.282 to 0.415) with the SDMT score, a measurement of cognitive information processing speed. The intraclass correlation coefficient (ICC) values of the CRIq total and CRIq sections ranged between 0.942 to 0.998, indicating a strong correlation.

Conclusions: The Hebrew version of the CRIq is a reliable and valid tool for assessing cognitive reserve in pwMS, hence enabling clinicians and researchers to effectively monitor cognitive reserve in this population.