Clinimetrics of the cognitive section of the Italian ALS Cognitive Behavioral Screen (ALS-CBS™)

Background: The present study aimed at (1) providing further validity and reliability evidence for the Italian version of the cognitive section of the ALS Cognitive Behavioral Screen (ALS-CBS™) and (2) testing its diagnostics within an Italian ALS cohort, as well as at (3) exploring its capability to discriminate patients from healthy controls (HCs).

Methods: N = 293 non-demented ALS patients were administered the cognitive sections of the ALS-CBS™ and Edinburgh Cognitive and Behavioural ALS Screen (ECAS). N = 96 HCs demographically matched with N = 96 patients were also administered the cognitive section of the ALS-CBS™. In patients, factorial and construct validity, internal reliability, and diagnostics against a defective score on the cognitive section of the ECAS were tested. Case-control discrimination was assessed via a logistic regression.

Results: ALS-CBS™ cognitive subscales were underpinned by a simple, unidimensional structure, internally reliable (McDonald's ω = 0.74), and mostly related with ECAS executive and fluency scores (r_s = 0.54-0.71). Both raw and age- and education-adjusted scores on the cognitive section of the ALS-CBS™ accurately detected ECAS-defined cognitive impairment (AUC = 0.80 and .88, respectively), yielding optimal error-based, information-based and unitary diagnostics. A cut-off of < 15.374 was identified on adjusted scores. The test was able to discriminate patients from HCs (p < 0.001).

Discussion: The cognitive section of the Italian ALS-CBS™ is a valid, reliable, and diagnostically sound ALS-specific screener for detecting frontotemporal, executive-/attentive-based cognitive inefficiency in non-demented ALS patients, being also able to discriminate them from normotypical individuals.