Discusión

The Vineland ABS and the updated Vineland-II^∗ have been widely and effectively used in clinical and research settings for the past 26 years (Middleton, Keene, &

Brown, 1990; Sparrow, Balla, & Cicchetti, 1984; Sparrow & Cicchetti, 1985; and Sparrow et al., 2005). It has been used with patients with PKU (Kalkanoglu et al., 2005; Lee et al., 2009; and Matthews, Barabas, Cusack, & Ferrari, 1986), children with Down syndrome (Kishnani et al., 2010), children with neurodevelopmental disabilities (Msall, 2005), and individuals with autism (Carter et al., 1998; Freeman, Del'Homme, Guthrie, & Zhang, 1999; Kanne et al., 2010; Kraijer, 2000; Paul et al., 2004; and Ray-Subramanian, Huai, & Ellis, 2011). It has also been used to study the effects of early maltreatment of children on their development (Becker-Weidman,

∗The Vineland-II was updated in 2005 with new norms, improved items, expanded age range, and improved overall organisation of the domains and sub-domains.

2009) and to compare the similarities and the differences in the adaptive behaviours of several common genetic syndromes (Di Nuovo & Buono, 2011).

4.3.1 The Vineland and PKU

The Vineland scales have been used with some patients with PKU at GOSH and KFSH&RC, and there are several reports of research studies that have used the Vineland with patients with PKU. It was used with PKU patients in two double blind placebo-controlled studies (Kalkanoglu et al., 2005; and Lee et al., 2009). Both studies involved untreated adult PKU patients who were diagnosed late and had severe intellectual disabilities. Lee and colleagues tested the benefits of phenylalanine restricted diet on their group in the UK. The Vineland was part of the assessment process at several points of this trial. The other study by Kalkanoğlu and colleagues looked at the effects of phenylalanine-free essential amino acid tablets on the performance of their group of PKU patients in Denmark. They used a simplified version of the Vineland to assess their patients at specified intervals.

Matthews (1986) used the Vineland to demonstrate that early treated children with PKU had deteriorated in social functioning after discontinuing the low phenylalanine diet at the age of 5.5 years on average; the scores of these patients were negatively correlated with their blood phenylalanine levels. In one report of the Maternal PKU Collaborative Study Waisbren and colleagues (2000) used the Vineland, among other tests, to assess the children of mothers with PKU. Their objective was to establish how the development of these children is affected by the timing of dietary treatment and metabolic control, or lack of it, of the mothers during pregnancy.

4.3.2 The relation of the Vineland to other scales

The Vineland-II validation studies, reported by Sparrow and colleagues (2005), show a very high correlation between the Vineland-II and the Vineland ABS, indicating a high degree of consistency between the two scales. The Vineland-II scales have retained most of the original items in the Vineland ABS. It has been improved by deleting a few items related to behaviours that are no longer common, by adding new items to expand the age range of the tool, and by increasing the density of the items in the first 3 years of life to improve the measure of adaptive behaviour in this

vulnerable period of development. The updated items also reflect the changes in culture and incorporate new knowledge about development. Having this strong relationship between the Vineland-II and the Vineland ABS is essential. It allows the transfer of the experiences gained from using the Vineland ABS for many years to the Vineland-II, and permits the research carried on with the Vineland ABS to support the Vineland-II as well (Sparrow et al., 2005).

Several studies have demonstrated high concurrent validity and correlation between the scores of the Vineland ABS and different tests of intelligence. Middleton et al (1990) examined the relation between the scores of the Vineland ABS and that of the Scales of Independent Behaviour (SIB), which is another measure of adaptive

behaviour, and found high correlation between them (r = 0.83). Sattler (2002) and Rosenbaum et al (1995) report good correlation between the Vineland ABS and several tests of intelligence, language, motor functions and academic achievement.

The authors of the Vineland-II report its validity in its ability to support the diagnosis of a range of disorders and describe deficits and levels of adaptive performance (Sparrow et al., 2005). To confirm this, individuals with intellectual disability, autism, emotional or behavioural disturbance, attention deficit hyperactivity disorder, learning disability, and visual or hearing impairments were assessed with the Vineland-II.

Individuals in each of these clinical groups were previously diagnosed and assessed by the appropriate clinical or psychometric assessments particular to each diagnosis, for example the Autism Diagnostic Interview-Revised or the Autism Diagnostic Observation Schedule for autism patients, and the Wechsler Intelligence Scale for Children for mental disability patients. The scores were compared with a normally developing reference group. The Vineland-II differentiated between the clinical groups and the normal group, it identified the adaptive deficits found in the patients and distinguished between the different levels of severity in each disorder (Sparrow et al., 2005). This provided evidence that the Vineland-II would be a good measure to use with patients with PKU.

4.3.3 Developmental assessment tools used for assessing patients with PKU Research and studies involving patients with PKU have used many different tools to assess the developmental levels of the patients. There is no consensus on the best tests

to be used with patients with PKU which makes comparability of research results somewhat limited. Formerly IQ tests were the main measures to assess the effects of PKU on patients. Lately the patients are assessed more through neuropsychological evaluations (Griffiths, Demellweek, Fay, Robinson, & Davidson, 2000). This includes behavioural, cognitive, language, motor, and executive functioning assessments, as a distinct psychosocial profile for patients with PKU is still unidentified (Weglage, 2000).

DeRoche and Welsh (2008) carried out a meta-analysis of 33 studies from 1980 to 2004. They were studies that investigated executive function and intelligence for early treated patients with PKU. There were many tools used to assess intelligence in the analysed studies, but there was no significant difference between their results.

However, there was a significant difference between the results of executive function studies that were analysed. The difference was in the measurement tools and date of the study, more recent studies showed a higher incidence of executive function deficits and some executive function test tools reported more deficits than others. The authors pointed out that the research community has no agreement on the best tool to measure the executive function domain for PKU patients (DeRoche & Welsh, 2008).

In another meta-analysis, Burgard (2000) reviewed longitudinal studies that looked at the IQ of early treated patients with PKU. Smith and Knowles (2000), in a systematic review, looked at the research that studied behaviour for early treated patients with PKU. Various tools to measure intelligence and behaviour were used in these reviewed studies as well. Below are the tools used in the reviewed studies (Burgard, 2000; DeRoche & Welsh, 2008; and Smith & Knowles, 2000), however this is not a comprehensive list of all the tools used for patients with PKU.

Tools used to assess intelligence:

∗ Stanford Binet

∗ Cultural Fair Intelligence test

∗ Wide Range Achievement test (WRAT)

∗ Colombia Mental Maturity Scale (CMMS)

∗ Wechsler Intelligence Scale for Children (WISC)

∗ Wechsler Intelligence Scale for Children- Revised (WISC-R)

∗ Wechsler Preschool and Primary Scales of Intelligence (WIPPSI)

∗ Wechsler Adult Intelligence Scale (WAIS)

∗ Wechsler Adult Intelligence Scale-Revised (WAIS-R)

∗ Hamburg Wechsler Intelligenztest für Kinder (HAWIK, German WISC)

∗ Hamburg Wechsler Intelligenztest für Kinder-Revision (HAWIK-R, German WISC-R)

∗ Hannover Wechsler Intelligenztest für das Vorschulalter (HAWIVA, German WIPPSI)

∗ Hamburg Wechsler Intelligenztest für Erwachsene- Revision (HAWIE-R, German WAIS-R)

∗ Terman-Merril method

∗ Raven’s Progressive Matrices

Tools used to assess executive function:

∗ Amsterdam Neuropsychological Test

∗ Behavior Rating Inventory of Executive Function (BRIEF)

∗ Contingency Naming Task

∗ Wisconsin Card Sorting Task (WCST)

∗ Stroop Tests

∗ Rey complex Figure Task

∗ Tower Tests

∗ Continuous Performance Task

∗ Corsi-Millner

∗ California Verbal Learning Test

∗ Design Fluency Task

∗ Luria-Nebraska

∗ McCarthy Scales

∗ Thurstone Letter Fluency

∗ Other experimental executive function measures created by different authors

Tools used to assess behaviour:

∗ Rutter Behaviour Scale for Teachers (RBST)

∗ Personlichkeitsfragebogen für Kinder (PFK, German Personality Questionnaire for Children)

∗ Freiburger Personlichkeits-Inventar (FPI, German Freiburg Personality Inventory)

∗ Mannheimer Biographical Inventory (MBI)

∗ Mannheimer Eltern Interview (MEI)

∗ The Minnesota Multiphasic Personality Inventory (MMPI)

∗ Mobility Inventory (MI)

Waisbren and White (2010) called for or the use of what their group have named as the “Uniform Assessment Method” for PKU. It is a battery of specific tests and tools to be used with patients with PKU to screen for problems in adaptive behaviour, social/emotional function and executive function. The tests are the Adaptive Behavior Assessment System - Second Edition (ABAS-II) for patients 0-2 years; the Behavior Rating Inventory of Executive Function (BRIEF) and Behavior Assessment System for Children - Second Edition (BASC-II) for patients 2-17 years; and for adult

patients the BRIEF, Beck Anxiety Inventory (BAI), and Beck Depression Inventory - Second Edition (BDI-II). The authors recommended that these specific tests be used in PKU clinics in routine visits, they do not need to be administered by psychologists and they take less than an hour to be administered. This would identify patients who need further assessments early on, provide long-term monitoring of PKU outcome, and provide a uniform source of results and research data that is from a uniform set of assessment tools across many clinics. They then recommended another battery of tests for patients who are identified to need further assessments and for high risk patients (Waisbren & White, 2010). This appears to be a good idea for all PKU clinics to follow, but there is no evidence yet that this has become regular practice.