title: Is BRIEF a useful instrument in day to day care of patients with phenylketonuria?
abstract: OBJECTIVE
  Despite early and continuous treatment many patients with phenylketonuria (PKU) still experience neurocognitive problems. Most problems have been observed in the domain of executive functioning (EF). For regular monitoring of EF, the use of the Behavior Rating Inventory of Executive Function (BRIEF) has been proposed. The aim of this study was to investigate whether the BRIEF is indeed a useful screening instrument in monitoring of adults with PKU.
  
  
  METHODS
  Adult PKU patients (n = 55; mean age 28.3 ± 6.2 years) filled out the BRIEF-A (higher scores=poorer EF) and performed computerized tasks measuring executive functions (inhibition, cognitive flexibility, and working memory). The outcome of the BRIEF-A questionnaire was compared with the neurocognitive outcome as measured by three tasks from the Amsterdam Neuropsychological Tasks (ANT).
  
  
  RESULTS
  Forty-two percent of the PKU patients scored in the borderline/clinical range of the BRIEF-A. Six of the 55 patients (11%) scored >1 SD above the normative mean, mostly on the Metacognition Index. With respect to ANT measurements, patients mainly showed deficits in inhibitory control (34-36%) and cognitive flexibility (31-40%) as compared to the general Dutch population. No significant correlations between the two methods were found, which was confirmed with the Bland-Altman approach where no agreement between the two methods was observed. Only with respect to inhibitory control, patients scored significantly worse on both BRIEF-A and ANT classifications. No other associations between classification according to the BRIEF-A and classifications according to the ANT tasks were found.
  
  
  CONCLUSIONS
  Patients reporting EF problems in daily life are not necessarily those that present with core EF deficits. The results of this study suggest that regular self-administration of the BRIEF-A is not a sufficient way to monitor EF in adult PKU patients.
authors.affiliation: Division of Metabolic Diseases, Beatrix Children's Hospital, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Geertje B
authors.initials: GB
authors.lastname: Liemburg
authors.affiliation: Division of Metabolic Diseases, Beatrix Children's Hospital, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Rianne
authors.initials: R
authors.lastname: Jahja
authors.affiliation: Division of Metabolic Diseases, Beatrix Children's Hospital, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Francjan J
authors.initials: FJ
authors.lastname: van Spronsen
authors.affiliation: Department of Clinical Child and Adolescents Studies, Leiden Institute for Brain and Cognition, Leiden University, Leiden, The Netherlands.
authors.forename: Leo M J
authors.initials: LM
authors.lastname: de Sonneville
authors.affiliation: Department of Developmental and Clinical Neuropsychology, University of Groningen, Groningen, The Netherlands.
authors.forename: Jaap J
authors.initials: JJ
authors.lastname: van der Meere
authors.affiliation: Department of Pediatrics, Emma Children's Hospital, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Annet M
authors.initials: AM
authors.lastname: Bosch
authors.affiliation: Department of Internal Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Carla E M
authors.initials: CE
authors.lastname: Hollak
authors.affiliation: Department of Pediatrics, Maastricht University Medical Center, Maastricht, The Netherlands.
authors.forename: M Estela
authors.initials: ME
authors.lastname: Rubio-Gozalbo
authors.affiliation: Department of Internal Medicine and Endocrinology, Maastricht University Medical Center, Maastricht, The Netherlands.
authors.forename: Martijn C G J
authors.initials: MC
authors.lastname: Brouwers
authors.affiliation: Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Floris C
authors.initials: FC
authors.lastname: Hofstede
authors.affiliation: Department of Pediatrics, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
authors.forename: Maaike C
authors.initials: MC
authors.lastname: de Vries
authors.affiliation: Department of Internal Medicine, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
authors.forename: Mirian C H
authors.initials: MC
authors.lastname: Janssen
authors.affiliation: Department of Pediatrics, Erasmus University Medical Center, Rotterdam, The Netherlands.
authors.forename: Ans T
authors.initials: AT
authors.lastname: van der Ploeg
authors.affiliation: Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands.
authors.forename: Janneke G
authors.initials: JG
authors.lastname: Langendonk
authors.affiliation: Department of Clinical Child and Adolescents Studies, Leiden Institute for Brain and Cognition, Leiden University, Leiden, The Netherlands. Electronic address: shuijbregts@fsw.leidenuniv.nl.
authors.forename: Stephan C J
authors.initials: SC
authors.lastname: Huijbregts
mesh_terms: D000328:Adult; D056344:Executive Function; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010649:Phenylalanine / Q000097:blood; D010661:Phenylketonurias / Q000523:psychology*; D011795:Surveys and Questionnaires
chemical_list: D010649:Phenylalanine
keywords: ANT; Adults; BRIEF-A; Executive functioning; Inborn error of metabolism; Phenylketonuria