Validity and reliability measures of the Swedish Karolinska version of the Edinburgh Cognitive and Behavioral ALS Screen (SK-ECAS)

Figures & data

Table 1 Participant characteristics and scores in cognitive testing (ECAS and MoCA).

	ALS/MND patients (n = 176)	ALS patients (n = 145)	MND patients other than ALS (n = 31)	Healthy controls (n = 35)
Sex, number (%)
Female	77 (43.8)	68 (46.9)	9 (29.0)	21 (60.0)
Male	99 (56.2)	77 (53.1)	22 (71.0)	14 (40.0)
Age in years, mean (SD)	64.2 (11.5)	64.3 (11.4)	63.8 (11.8)	61.7 (11.6)
MoCA score, mean (SD) (max 30)**	26.4 (2.7)	25.9 (2.9)	26.5 (2.3)	28.0 (1.8)
ALSFRS-R score at time of ECAS measure, mean (SD)	37.2 (8.3)	36.7 (8.5)	39.7 (6.9)	–
ECAS total score, mean (SD) (max 136)**	107.6 (14.1)	106.6 (14.6)	112.3 (10.5)	120.8 (6.4)
ECAS ALS-specific score, mean (SD) (max /100)**	79.9 (11.1)	79.1 (11.5)	83.8 (8.1)	90.1 (4.7)
ECAS non-ALS-specific score, mean (SD) (max 36)*	27.7 (5.5)	27.6 (5.7)	28.5 (4.4)	30.7 (3.0)

ALS: amyotrophic lateral sclerosis; MND: motor neuron disease; ECAS: Edinburgh Cognitive and Behavioral ALS Screen; MoCA: Montreal Cognitive Assessment; ALSFRS-R: ALS functional rating scale revised.

* p < 0.01 comparing ALS/MND patients to healthy controls.

** p < 0.001 comparing ALS/MND patients to healthy controls.

Table 2 Spearman correlation coefficients and p values between different cognitive measures among 176 ALS/MND patients and 35 healthy controls.

	SK-ECAS total	SK-ECAS ALS-specific	SK-ECAS non-ALS-specific	MoCA
SK-ECAS total
ALS/MND patients	1	0.92, p < 0.0001	0.62, p < 0.0001	0.54, p < 0.0001
Healthy controls	1	0.94, p < 0.0001	0.69, p < 0.0001	0.53, p = 0.0012
SK-ECAS ALS-specific
ALS/MND patients	0.92, p < 0.0001	1	0.30, p < 0.0001	0.44, p < 0.0001
Healthy controls	0.94, p < 0.0001	1	0.43, p = 0.0091	0.46, p = 0.0059
SK-ECAS non-ALS-specific
ALS/MND patients	0.62, p < 0.0001	0.30, p < 0.0001	1	0.47, p < 0.0001
Healthy controls	0.69, p < 0.0001	0.43, p = 0.0091	1	0.41, p = 0.0138
MoCA
ALS/MND patients	0.54, p < 0.0001	0.44, p < 0.0001	0.47, p < 0.0001	1
Healthy controls	0.53, p = 0.0012	0.46, p = 0.0059	0.41, p = 0.0138	1

ALS: amyotrophic lateral sclerosis; MND: motor neuron disease; SK-ECAS: Swedish Edinburgh Cognitive and Behavioral ALS Screen at the Karolinska University Hospital; MoCA: Montreal Cognitive Assessment.

Figure 1 ECAS ROC detecting cognitive impairment defined as a pathologic MoCA score. (A) ECAS total score (best cutoff = 108). (B) ECAS ALS-specific score (best cutoff = 82). ECAS: Edinburgh Cognitive and Behavioral ALS Screen; ROC: Receiver operating characteristic; MoCA: Montreal Cognitive Assessment.

Table 3 Sensitivity, specificity, and predictive values of cutoff values for SK-ECAS ALS-specific and total scores.

Score	Cutoff	Sensitivity	Specificity	Positive predictive value	Negative predictive value	Point Estimate	95% Wald confidence limits
SK-ECAS total score	105	0.58	0.84	0.73	0.73	0.134	0.066	0.272
	107	0.61	0.80	0.69	0.74	0.157	0.080	0.309
	108	0.69	0.78	0.70	0.78	0.124	0.063	0.245
	110	0.72	0.73	0.65	0.78	0.150	0.077	0.292
	115	0.81	0.47	0.53	0.77	0.263	0.130	0.528
SK-ECAS ALS-specific score	77	0.51	0.80	0.65	0.69	0.231	0.118	0.451
	78	0.51	0.80	0.65	0.69	0.231	0.118	0.451
	80	0.59	0.75	0.63	0.72	0.233	0.123	0.444
	82	0.66	0.72	0.63	0.74	0.203	0.106	0.387
	83	0.73	0.62	0.58	0.76	0.229	0.120	0.439

ALS: amyotrophic lateral sclerosis; ECAS: Edinburgh Cognitive and Behavioral ALS Screen.