Ecological validity of performance-based cognitive screeners in amyotrophic lateral sclerosis: preliminary evidence.

Background: This study aimed at preliminarily assessing, in a cohort of non-demented amyotrophic lateral sclerosis (ALS) patients, the ecological validity, and more specifically the veridicality, of the Edinburgh Cognitive and Behavioural ALS Screen (ECAS) and the ALS Cognitive Behavioral Screen (ALS-CBS™), by relating their scores to caregiver-report ratings of cognitive changes.

Methods: N = 147 patient-caregiver dyads were recruited. Patients were administered the ECAS and ALS-CBS™, whilst caregiver the Caregiver Behavioral Questionnaire (CBQ) and Beaumont Behavioural Inventory (BBI). An Ecological Cognitive Functioning Index (ECFI) was derived from those items of the CBQ and BBI that tap on executive and language changes. Ecological validity was assessed via both correlational and predictive analyses net of caregiver-rated behavioural changes (as assessed by the ECAS-Carer Interview).

Results: The ECFI was associated with the total scores on both the ECAS (p = .014) and ALS-CBS™ (p = .017). When looking at ECAS and ALS-CBS™ subscales, those assessing verbal fluency were selectively associated with the ECFI. The ECFI was higher in patients performing defectively on the ECAS (p = .004) and on the ALS-CBS™ (p = .027).

Discussion: This study suggests that both the ECAS and the ALS-CBS™ represent a valid estimate of non-demented ALS patients' cognitive status in the real world, also highlighting the clinical relevance of cognitive changes reported by caregivers.