Diagnostic properties of the Italian ECAS Carer Interview (ECAS-CI)

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.

Equating norms between the ALS Cognitive Behavioral Screen (ALS-CBS™) and the Edinburgh Cognitive and Behavioural ALS Screen (ECAS) in non-demented ALS patients

BACKGROUND

The present study aimed at deriving equating norms to estimate scores on the Edinburgh Cognitive and Behavioural ALS Screen (ECAS) based on those on the ALS Cognitive Behavioral Screen (ALS-CBS™) in an Italian cohort of non-demented ALS patients.

METHODS

ALS-CBS™ and ECAS scores of 293 ALS patients without frontotemporal dementia were retrospectively retrieved. Concurrent validity of the ALS-CBS™ towards the ECAS was tested by covarying for demographics, disease duration and severity, presence of C9orf72 hexanucleotide repeat expansion and behavioural features. A linear-smoothing equipercentile equating (LSEE) model was employed to derive ALS-CBS™-to-ECAS cross-walks. Gaps in LSEE-based estimation were managed via a linear regression-based equating approach. Equivalence between empirical and derived ECAS scores was tested via a two-one-sided test (TOST) procedure for the dependent sample.

RESULTS

The ALS-CBS™ predicted the ECAS (β = 0.75), accounting for the vast majority of its variance (60% out of an R² = 0.71). Consistently, a strong, one-to-one linear association between ALS-CBS™ and ECAS scores was detected (r = 0.84; R² = 0.73). The LSEE was able to estimate conversions for the full range of the ALS-CBS™, except for raw scores equal to 1 and 6 - for whom a linear equating-based equation was derived. Empirical ECAS scores were equivalent to those derived with both methods.

DISCUSSION

Italian practitioners and researchers have been herewith provided with valid, straightforward cross-walks to estimate the ECAS based on ALS-CBS™ scores in non-demented ALS patients. Conversions herewith provided will help avoid cross-sectional/longitudinal inconsistencies in test adoption within research, and possibly clinical, settings.

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.

Standardization of the Italian ALS-CBS™ Caregiver Behavioral Questionnaire

Background

The present investigation aimed at testing the psychometrics and diagnostics of the Italian version of the Caregiver Behavioral Questionnaire (CBQ) from the ALS Cognitive Behavioral Screen (ALS-CBS™), as well as its case-control discrimination, in a cohort of non-demented patients with ALS.

Methods

The caregivers of N = 265 non-demented patients with ALS and N = 99 healthy controls (HCs) were administered the CBQ and the Edinburgh Cognitive and Behavioural ALS Screen-Carer Interview (ECAS-CI). For N = 98 patients, an in-depth behavioural/psychopathological assessment via the Frontal Behavioural Inventory (FBI), the Dimensional Apathy Scale (DAS), the State and Trait Anxiety Inventory-Form Y (STAI-Y), and the Beck Depression Inventory (BDI) was also available. Factorial and construct validity, internal reliability, and diagnostics against an abnormal ECAS-CI score were tested in patients. Case-control discrimination was explored through logistic regression.

Results

The CBQ was internally reliable (McDonald's ω = 0.90) and underpinned by a simple, unidimensional structure; it converged with ECAS-CI, FBI, and DAS scores and diverged from STAI-Y and BDI ones. A cutoff of ≤ 33 accurately detected abnormal ECAS-CI scores (AUC = 0.85), yielding optimal error- and information-based diagnostics. The CBQ was independent of demographic and disease-related variables and discriminated patients from HCs (p < 0.001).

Discussion

The Italian version of the CBQ from the ALS-CBS™ is a valid, reliable, diagnostically sound, and feasible screener for detecting frontotemporal-like behavioural changes in non-demented patients with ALS. Its adoption is thus recommended within clinical practice and research in the view of providing preliminary information on whether the administration of more extensive behavioural instruments is needed.