Analysis of cognitive ability and adaptive behavior assessment tools used in an observational study of patients with mucopolysaccharidosis II

Table 1 Components of the DAS-II and VABS-II assessment tools

	DAS-II	VABS-II
Composite scores	GCA (overall score of cognitive performance) Derived from verbal and non-verbal cluster scores (all), and spatial cluster score (upper EY^a and SA only) SNC (similar to GCA but does not include verbal tests)	ABC (overall score of adaptive behavioral ability) Derived from all four domains for patients aged < 7 years and from three domains (motor skills excluded) for patients aged ≥ 7 years
Cluster/domain scores and component subtest/subdomain scores	Verbal Verbal comprehension (EY) Naming vocabulary (EY) Word definitions (SA) Verbal similarities (SA) Non-verbal Picture similarities (EY) Matrices (EY and SA) Sequential and quantitative reasoning (SA) Spatial Copying (EY) Pattern construction (EY and SA) Recall of designs (SA)	Communication Receptive Expressive Written Daily living skills Personal Domestic Community Socialization Interpersonal relationships Play and leisure time Coping skills Motor skills Gross Fine
Normative mean (SD)^b	Composite and cluster scores: 100 (15)^c Subtest scores: 50 (10)^d	ABC and domain scores: 100 (15) Subdomain scores: 15 (3)

ABC Adaptive Behavior Composite; DAS-II Differential Ability Scales, second edition; EY early years (2 years 6 months–6 years 11 months); GCA General Conceptual Ability; SA school age (7 years–17 years 11 months); SD standard deviation; SNC Special Nonverbal Composite; VABS-II Vineland Adaptive Behavior Scales, second edition
^aThe DAS-II early years test battery comprises a lower level for children aged 2 years 6 months to 3 years 5 months and an upper level for those aged 3 years 6 months to 6 years 11 months
^bDAS-II composite/cluster scores and subtest scores are normed on different scales and ABC/domain scores and subdomain scores are also normed on different scales
^cComposite scores were the sums of subtest T scores normed; cluster scores were the sum of two normalized subtest T scores
^dNormalized T scores were used for all subtest scores

ISSN: 1750-1172