Core Outcome Sets for Medium-Chain Acyl-CoA Dehydrogenase Deficiency and Phenylketonuria.

BACKGROUND: Evidence to guide treatment of pediatric medium-chain acyl-coenzyme A dehydrogenase (MCAD) deficiency and phenylketonuria (PKU) is fragmented because of large variability in outcome selection and measurement. Our goal was to develop core outcome sets (COSs) for these diseases to facilitate meaningful future evidence generation and enhance the capacity to compare and synthesize findings across studies. METHODS: Parents and/or caregivers, health professionals, and health policy advisors completed a Delphi survey and participated in a consensus workshop to select core outcomes from candidate lists of outcomes for MCAD deficiency and PKU. Delphi participants rated the importance of outcomes on a nine-point scale (1-3: not important, 4-6: important but not critical, 7-9: critical). Candidate outcomes were progressively narrowed down over 3 survey rounds. At the workshop, participants evaluated the remaining candidate outcomes using an adapted nominal technique, open discussion, and voting. After the workshop, we finalized the COSs and recommended measurement instruments for each outcome. RESULTS: There were 85, 61, and 53 participants across 3 Delphi rounds, respectively. The candidate core outcome lists were narrowed down to 20 outcomes per disease to be discussed at the consensus workshop. Voting by 18 workshop participants led to COSs composed of 8 and 9 outcomes for MCAD deficiency and PKU, respectively, with measurement recommendations. CONCLUSIONS: These are the first known pediatric COSs for MCAD deficiency and PKU. Adoption in future studies will help to ensure best use of limited research resources to ultimately improve care for children with these rare diseases.

Confirmatory factor analysis of the Reynolds Intellectual Assessment Scales (RIAS) in Canadian children.

The purpose of the current study was to assess the validity of the Reynolds Intellectual Assessment Scale's (RIAS) index and subtest scores by examining whether the RIAS conforms to Carroll's ( 1993 ) three-stratum theory of cognitive ability and the Cattell-Horn Gf-Gc (Horn & Cattell, 1966 ) theory of intelligence upon which it was based. Factor structures of RIAS scores from typically developing (n = 187) and mixed clinical groups (n = 164), 4-18 years old, were compared using confirmatory factor analysis. The results were mixed, with some findings supporting the validity of the Composite Intelligence Index (CIX), Nonverbal Intelligence Index (NIX), and Verbal Intelligence Index (VIX) while others suggested that the CIX and NIX in particular should be interpreted with caution, depending on the population in which the RIAS is being used. The functioning of the two nonverbal subtests in all analyses suggested that the RIAS's nonverbal subtests are most problematic, with the greatest impact on the RIAS's validity as a measure of overall, verbal, and nonverbal intelligence. The RIAS's use as a general cognitive screener is supported but caution is recommended if the RIAS is being used to make important diagnostic, qualification for services, forensic, or placement decisions.