Improving IQ measurement in intellectual disabilities using true deviation from population norms / Stephanie M. SANSONE in Journal of Neurodevelopmental Disorders, 6-1 (December 2014)  

Public ISBD [article]  inJournal of Neurodevelopmental Disorders > 6-1 (December 2014) . - p.16 Titre : Improving IQ measurement in intellectual disabilities using true deviation from population norms Type de document : Texte imprimé et/ou numérique Auteurs : Stephanie M. SANSONE, Auteur ; A. SCHNEIDER, Auteur ; E. BICKEL, Auteur ; Elizabeth BERRY-KRAVIS, Auteur ; C. PRESCOTT, Auteur ; D. HESSL, Auteur Article en page(s) : p.16 Langues : Anglais (eng) Mots-clés : Autism spectrum disorder  Cognitive assessment  Fragile X syndrome  Iq  Intellectual disability Index. décimale : PER Périodiques Résumé : BACKGROUND: Intellectual disability (ID) is characterized by global cognitive deficits, yet the very IQ tests used to assess ID have limited range and precision in this population, especially for more impaired individuals. METHODS: We describe the development and validation of a method of raw z-score transformation (based on general population norms) that ameliorates floor effects and improves the precision of IQ measurement in ID using the Stanford Binet 5 (SB5) in fragile X syndrome (FXS; n = 106), the leading inherited cause of ID, and in individuals with idiopathic autism spectrum disorder (ASD; n = 205). We compared the distributional characteristics and Q-Q plots from the standardized scores with the deviation z-scores. Additionally, we examined the relationship between both scoring methods and multiple criterion measures. RESULTS: We found evidence that substantial and meaningful variation in cognitive ability on standardized IQ tests among individuals with ID is lost when converting raw scores to standardized scaled, index and IQ scores. Use of the deviation z- score method rectifies this problem, and accounts for significant additional variance in criterion validation measures, above and beyond the usual IQ scores. Additionally, individual and group-level cognitive strengths and weaknesses are recovered using deviation scores. CONCLUSION: Traditional methods for generating IQ scores in lower functioning individuals with ID are inaccurate and inadequate, leading to erroneously flat profiles. However assessment of cognitive abilities is substantially improved by measuring true deviation in performance from standardization sample norms. This work has important implications for standardized test development, clinical assessment, and research for which IQ is an important measure of interest in individuals with neurodevelopmental disorders and other forms of cognitive impairment. En ligne : http://dx.doi.org/10.1186/1866-1955-6-16 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=346 [article] Improving IQ measurement in intellectual disabilities using true deviation from population norms [Texte imprimé et/ou numérique] / Stephanie M. SANSONE, Auteur ; A. SCHNEIDER, Auteur ; E. BICKEL, Auteur ; Elizabeth BERRY-KRAVIS, Auteur ; C. PRESCOTT, Auteur ; D. HESSL, Auteur . - p.16. Langues : Anglais (eng) in Journal of Neurodevelopmental Disorders > 6-1 (December 2014) . - p.16 Mots-clés : Autism spectrum disorder  Cognitive assessment  Fragile X syndrome  Iq  Intellectual disability Index. décimale : PER Périodiques Résumé : BACKGROUND: Intellectual disability (ID) is characterized by global cognitive deficits, yet the very IQ tests used to assess ID have limited range and precision in this population, especially for more impaired individuals. METHODS: We describe the development and validation of a method of raw z-score transformation (based on general population norms) that ameliorates floor effects and improves the precision of IQ measurement in ID using the Stanford Binet 5 (SB5) in fragile X syndrome (FXS; n = 106), the leading inherited cause of ID, and in individuals with idiopathic autism spectrum disorder (ASD; n = 205). We compared the distributional characteristics and Q-Q plots from the standardized scores with the deviation z-scores. Additionally, we examined the relationship between both scoring methods and multiple criterion measures. RESULTS: We found evidence that substantial and meaningful variation in cognitive ability on standardized IQ tests among individuals with ID is lost when converting raw scores to standardized scaled, index and IQ scores. Use of the deviation z- score method rectifies this problem, and accounts for significant additional variance in criterion validation measures, above and beyond the usual IQ scores. Additionally, individual and group-level cognitive strengths and weaknesses are recovered using deviation scores. CONCLUSION: Traditional methods for generating IQ scores in lower functioning individuals with ID are inaccurate and inadequate, leading to erroneously flat profiles. However assessment of cognitive abilities is substantially improved by measuring true deviation in performance from standardization sample norms. This work has important implications for standardized test development, clinical assessment, and research for which IQ is an important measure of interest in individuals with neurodevelopmental disorders and other forms of cognitive impairment. En ligne : http://dx.doi.org/10.1186/1866-1955-6-16 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=346

Psychometric Study of the Aberrant Behavior Checklist in Fragile X Syndrome and Implications for Targeted Treatment / Stephanie M. SANSONE in Journal of Autism and Developmental Disorders, 42-7 (July 2012)  

Public ISBD [article]  inJournal of Autism and Developmental Disorders > 42-7 (July 2012) . - p.1377-1392 Titre : Psychometric Study of the Aberrant Behavior Checklist in Fragile X Syndrome and Implications for Targeted Treatment Type de document : Texte imprimé et/ou numérique Auteurs : Stephanie M. SANSONE, Auteur ; Keith F. WIDAMAN, Auteur ; Scott S. HALL, Auteur ; Allan L. REISS, Auteur ; Amy LIGHTBODY, Auteur ; Walter E. KAUFMANN, Auteur ; Elizabeth BERRY-KRAVIS, Auteur ; Ave LACHIEWICZ, Auteur ; Elaine C. BROWN, Auteur ; David HESSL, Auteur Année de publication : 2012 Article en page(s) : p.1377-1392 Langues : Anglais (eng) Mots-clés : FMR1 gene  Fragile X syndrome  Autism  Factor analysis  Rating scale  Social avoidance  Aberrant Behavior Checklist Index. décimale : PER Périodiques Résumé : Animal studies elucidating the neurobiology of fragile X syndrome (FXS) have led to multiple controlled trials in humans, with the Aberrant Behavior Checklist-Community (ABC-C) commonly adopted as a primary outcome measure. A multi-site collaboration examined the psychometric properties of the ABC-C in 630 individuals (ages 3–25) with FXS using exploratory and confirmatory factor analysis. Results support a six-factor structure, with one factor unchanged (Inappropriate Speech), four modified (Irritability, Hyperactivity, Lethargy/Withdrawal, and Stereotypy), and a new Social Avoidance factor. A comparison with ABC-C data from individuals with general intellectual disability and a list of commonly endorsed items are also reported. Reformulated ABC-C scores based on this FXS-specific factor structure may provide added outcome measure specificity and sensitivity in FXS clinical trials. En ligne : http://dx.doi.org/10.1007/s10803-011-1370-2 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=166 [article] Psychometric Study of the Aberrant Behavior Checklist in Fragile X Syndrome and Implications for Targeted Treatment [Texte imprimé et/ou numérique] / Stephanie M. SANSONE, Auteur ; Keith F. WIDAMAN, Auteur ; Scott S. HALL, Auteur ; Allan L. REISS, Auteur ; Amy LIGHTBODY, Auteur ; Walter E. KAUFMANN, Auteur ; Elizabeth BERRY-KRAVIS, Auteur ; Ave LACHIEWICZ, Auteur ; Elaine C. BROWN, Auteur ; David HESSL, Auteur . - 2012 . - p.1377-1392. Langues : Anglais (eng) in Journal of Autism and Developmental Disorders > 42-7 (July 2012) . - p.1377-1392 Mots-clés : FMR1 gene  Fragile X syndrome  Autism  Factor analysis  Rating scale  Social avoidance  Aberrant Behavior Checklist Index. décimale : PER Périodiques Résumé : Animal studies elucidating the neurobiology of fragile X syndrome (FXS) have led to multiple controlled trials in humans, with the Aberrant Behavior Checklist-Community (ABC-C) commonly adopted as a primary outcome measure. A multi-site collaboration examined the psychometric properties of the ABC-C in 630 individuals (ages 3–25) with FXS using exploratory and confirmatory factor analysis. Results support a six-factor structure, with one factor unchanged (Inappropriate Speech), four modified (Irritability, Hyperactivity, Lethargy/Withdrawal, and Stereotypy), and a new Social Avoidance factor. A comparison with ABC-C data from individuals with general intellectual disability and a list of commonly endorsed items are also reported. Reformulated ABC-C scores based on this FXS-specific factor structure may provide added outcome measure specificity and sensitivity in FXS clinical trials. En ligne : http://dx.doi.org/10.1007/s10803-011-1370-2 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=166

The NIH Toolbox Cognitive Battery for intellectual disabilities: three preliminary studies and future directions / D. HESSL in Journal of Neurodevelopmental Disorders, 8-1 (December 2016)  

Public ISBD [article]  inJournal of Neurodevelopmental Disorders > 8-1 (December 2016) . - p.35 Titre : The NIH Toolbox Cognitive Battery for intellectual disabilities: three preliminary studies and future directions Type de document : Texte imprimé et/ou numérique Auteurs : D. HESSL, Auteur ; Stephanie M. SANSONE, Auteur ; Elizabeth BERRY-KRAVIS, Auteur ; K. RILEY, Auteur ; K. F. WIDAMAN, Auteur ; Leonard ABBEDUTO, Auteur ; A. SCHNEIDER, Auteur ; J. COLEMAN, Auteur ; D. OAKLANDER, Auteur ; K. C. RHODES, Auteur ; R. C. GERSHON, Auteur Article en page(s) : p.35 Langues : Anglais (eng) Mots-clés : Assessment  Cognition  Down syndrome  FMR1 gene  Fragile X syndrome  Outcome measures Index. décimale : PER Périodiques Résumé : BACKGROUND: Recent advances in understanding molecular and synaptic mechanisms of intellectual disabilities (ID) in fragile X syndrome (FXS) and Down syndrome (DS) through animal models have led to targeted controlled trials with pharmacological agents designed to normalize these underlying mechanisms and improve clinical outcomes. However, several human clinical trials have failed to demonstrate efficacy of these targeted treatments to improve surrogate behavioral endpoints. Because the ultimate index of disease modification in these disorders is amelioration of ID, the validation of cognitive measures for tracking treatment response is essential. Here, we present preliminary research to validate the National Institutes of Health Toolbox Cognitive Battery (NIH-TCB) for ID. METHODS: We completed three pilot studies of patients with FXS (total n = 63; mean age 19.3 +/- 8.3 years, mean mental age 5.3 +/- 1.6 years), DS (n = 47; mean age 16.1 +/- 6.2, mean mental age 5.4 +/- 2.0), and idiopathic ID (IID; n = 16; mean age 16.1 +/- 5.0, mean mental age 6.6 +/- 2.3) measuring processing speed, executive function, episodic memory, word/letter reading, receptive vocabulary, and working memory using the web-based NIH-TB-CB, addressing feasibility, test-retest reliability, construct validity, ecological validity, and syndrome differences and profiles. RESULTS: Feasibility was good to excellent (>/=80 % of participants with valid scores) for above mental age 4 years for all tests except list sorting (working memory). Test-retest stability was good to excellent, and convergent validity was similar to or better than results obtained from typically developing children in the normal sample for executive function and language measures. Examination of ecological validity revealed moderate to very strong correlations between the NIH-TCB composite and adaptive behavior and full-scale IQ measures. Syndrome/group comparisons demonstrated significant deficits for the FXS and DS groups relative to IID on attention and inhibitory control, a significant reading weakness for FXS, and a receptive vocabulary weakness for DS. CONCLUSIONS: The NIH-TCB has potential for assessing important dimensions of cognition in persons with ID, and several tests may be useful for tracking response to intervention. However, more extensive psychometric studies, evaluation of the NIH-TCB's sensitivity to change, both developmentally and in the context of treatment, and perhaps establishing links to brain function in these populations, are required to determine the true utility of the battery as a set of outcome measures. En ligne : http://dx.doi.org/10.1186/s11689-016-9167-4 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=349 [article] The NIH Toolbox Cognitive Battery for intellectual disabilities: three preliminary studies and future directions [Texte imprimé et/ou numérique] / D. HESSL, Auteur ; Stephanie M. SANSONE, Auteur ; Elizabeth BERRY-KRAVIS, Auteur ; K. RILEY, Auteur ; K. F. WIDAMAN, Auteur ; Leonard ABBEDUTO, Auteur ; A. SCHNEIDER, Auteur ; J. COLEMAN, Auteur ; D. OAKLANDER, Auteur ; K. C. RHODES, Auteur ; R. C. GERSHON, Auteur . - p.35. Langues : Anglais (eng) in Journal of Neurodevelopmental Disorders > 8-1 (December 2016) . - p.35 Mots-clés : Assessment  Cognition  Down syndrome  FMR1 gene  Fragile X syndrome  Outcome measures Index. décimale : PER Périodiques Résumé : BACKGROUND: Recent advances in understanding molecular and synaptic mechanisms of intellectual disabilities (ID) in fragile X syndrome (FXS) and Down syndrome (DS) through animal models have led to targeted controlled trials with pharmacological agents designed to normalize these underlying mechanisms and improve clinical outcomes. However, several human clinical trials have failed to demonstrate efficacy of these targeted treatments to improve surrogate behavioral endpoints. Because the ultimate index of disease modification in these disorders is amelioration of ID, the validation of cognitive measures for tracking treatment response is essential. Here, we present preliminary research to validate the National Institutes of Health Toolbox Cognitive Battery (NIH-TCB) for ID. METHODS: We completed three pilot studies of patients with FXS (total n = 63; mean age 19.3 +/- 8.3 years, mean mental age 5.3 +/- 1.6 years), DS (n = 47; mean age 16.1 +/- 6.2, mean mental age 5.4 +/- 2.0), and idiopathic ID (IID; n = 16; mean age 16.1 +/- 5.0, mean mental age 6.6 +/- 2.3) measuring processing speed, executive function, episodic memory, word/letter reading, receptive vocabulary, and working memory using the web-based NIH-TB-CB, addressing feasibility, test-retest reliability, construct validity, ecological validity, and syndrome differences and profiles. RESULTS: Feasibility was good to excellent (>/=80 % of participants with valid scores) for above mental age 4 years for all tests except list sorting (working memory). Test-retest stability was good to excellent, and convergent validity was similar to or better than results obtained from typically developing children in the normal sample for executive function and language measures. Examination of ecological validity revealed moderate to very strong correlations between the NIH-TCB composite and adaptive behavior and full-scale IQ measures. Syndrome/group comparisons demonstrated significant deficits for the FXS and DS groups relative to IID on attention and inhibitory control, a significant reading weakness for FXS, and a receptive vocabulary weakness for DS. CONCLUSIONS: The NIH-TCB has potential for assessing important dimensions of cognition in persons with ID, and several tests may be useful for tracking response to intervention. However, more extensive psychometric studies, evaluation of the NIH-TCB's sensitivity to change, both developmentally and in the context of treatment, and perhaps establishing links to brain function in these populations, are required to determine the true utility of the battery as a set of outcome measures. En ligne : http://dx.doi.org/10.1186/s11689-016-9167-4 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=349

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