A validated web-based tool to display individualised Crohn's disease predicted outcomes based on clinical, serologic and genetic variables.

BACKGROUND: Early treatment for Crohn's disease (CD) with immunomodulators and/or anti-TNF agents improves outcomes in comparison to a slower 'step up' algorithm. However, there remains a limited ability to identify those who would benefit most from early intensive therapy. AIM: To develop a validated, individualised, web-based tool for patients and clinicians to visualise individualised risks for developing Crohn's disease complications. METHODS: A well-characterised cohort of adult patients with CD was analysed. Available data included: demographics; clinical characteristics; serologic immune responses; NOD2 status; time from diagnosis to complication; and medication exposure. Cox proportional analyses were performed to model the probability of developing a CD complication over time. The Cox model was validated externally in two independent CD cohorts. Using system dynamics analysis (SDA), these results were transformed into a simple graphical web-based display to show patients their individualised probability of developing a complication over a 3-year period. RESULTS: Two hundered and forty three CD patients were included in the final model of which 142 experienced a complication. Significant variables in the multivariate Cox model included small bowel disease (HR 2.12, CI 1.05-4.29), left colonic disease (HR 0.73, CI 0.49-1.09), perianal disease (HR 4.12, CI 1.01-16.88), ASCA (HR 1.35, CI 1.16-1.58), Cbir (HR 1.29, CI 1.07-1.55), ANCA (HR 0.77, CI 0.62-0.95), and the NOD2 frameshift mutation/SNP13 (HR 2.13, CI 1.33-3.40). The Harrell's C (concordance index for predictive accuracy of the model) = 0.73. When applied to the two external validation cohorts (adult n = 109, pediatric n = 392), the concordance index was 0.73 and 0.75, respectively, for adult and pediatric patients. CONCLUSIONS: A validated, web-based tool has been developed to display an individualised predicted outcome for adult patients with Crohn's disease based on clinical, serologic and genetic variables. This tool can be used to help providers and patients make personalised decisions about treatment options.

Phonological processing in reading Chinese among normally achieving and poor readers.

Ninety-four children in grades one to six (7 to 12 years old) in Hong Kong were individually administered a Chinese reading test consisting of 80 characters that varied in frequency (high or low) and orthographic structure (simple or complex). Phonological processing tasks, including short-term memory, pseudo-character recognition, and tone discrimination, were also administered. During reading, younger normal and poor readers made more semantic and visual errors, whereas older and normally achieving children made more phonologically related errors. Normally achieving readers also performed at a higher level than poor readers on short-term memory, pseudo-character recognition, and tone discrimination tasks. Phonological processing apparently plays a significant part in the development of reading skills in Chinese.

Short-term memory, working memory, and inhibitory control in children with difficulties in arithmetic problem solving.

The relations between short-term memory, working memory, inhibitory control, and arithmetic word problem solution were studied in children who were poor in arithmetic problem solving (n = 23). The children were compared with a group of good problem solvers (n = 26), matched for vocabulary, age, and gender. The results corroborate the hypothesis of poor problem solvers' general deficit in inhibitory processes. They had lower scores and made more intrusion errors in a series of working memory tasks requiring inhibition of irrelevant information. The results showed that problem solving performance is related to the ability of reducing the accessibility of nontarget and irrelevant information in memory. Span tasks that imply passive storage of information showed that poor problem solvers were impaired when they have to retain numerical information, but they did not differ from children who did not have difficulty with mathematics when the material included words.

Speech perception, lexicality, and reading skill.

This study examined the interaction between speech perception and lexical information among a group of 7-year-old children, of which 26 were poor readers and 36 were good readers. The children's performance was examined on tasks assessing reading skill, phonological awareness, pseudoword repetition, and phoneme identification. Although good readers showed clearly defined categorical perception in the phoneme identification task for both the /bif/-/pif/ and the /bis/-/pis/ continua, the category boundary for /bif/-/pif/ was at longer VOTs than the boundary for /bis/-/pis/, which characterizes the classic lexicality effect. Poor readers showed less sharply defined categorical perception on both continua. Although poor readers did not show the classic lexicality effect, lexicality did affect the overall rate with which phonemes were identified as /b/ or /p/ at each VOT. These findings suggest that the lexicon may operate as a compensatory mechanism for resolving ambiguities in speech perception. Furthermore, statistical correction for group differences in phoneme identification made group differences in phoneme deletion disappear, suggesting that deficits in speech perception may play a causal role in the phonological core deficit associated with reading failure.

Working memory, inhibitory control, and reading disability.

The relationships among working memory, inhibitory control, and reading skills were studied in 966 individuals, 6-49 years old. In addition to a standardized measure of word recognition, they received a working memory (listening span) task in the standard, blocked format (three sets containing two-, three-, or four-item trials) or in a mixed format (three sets each containing two-, three-, and four-item trials) to determine whether scores derived from the standard format are influenced by proactive interference. Intrusion errors were investigated in order to determine whether deficits in working memory were associated with the access, deletion, or restraint functions of inhibitory control. The results indicated that deficits in working memory were characteristic of individuals with reading disabilities at all ages. These deficits may be associated with the access and restraint functions of inhibition. Working memory skills increased until the age of 19. The blocked format showed a gradual decline in adulthood whereas the mixed format did not. The different patterns suggest that the decline in working memory skills associated with aging may result from growing inefficiencies in inhibitory control, and not diminished capacity.

Issues in the definition and diagnosis of learning disabilities: a perspective on Guckenberger v. Boston University.

This article reviews issues related to the definition of learning disabilities in the context of the Guckenberger v. Boston University case. Four major questions are addressed: (a) Who is learning disabled? (b) How should learning disabilities be assessed? (c) Who is qualified to make a decision about whether or not an individual has a learning disability? and (d) What accommodations should be provided by a postsecondary institution and how should they be selected? Although these are complicated and difficult questions, it is possible to develop a simple, reasonable classification system for learning disabilities, and to conduct assessments based on a coherent and relevant set of achievement tests in which individuals who score below a cutoff are considered learning disabled. Scores on IQ tests are irrelevant and not useful and may even be discriminatory. The issues of decision making regarding learning disabilities and appropriate accommodations remain significant dilemmas for the field; resolution of these issues seems virtually impossible without agreement on appropriate procedures for the definition, identification, and assessment of learning disabilities.

Reading and spelling acquisition in French: the role of phonological mediation and orthographic factors.

The objective of this research was to study the development of reading and spelling in French. The two main hypotheses were that (1) phonological mediation is the primary process in the acquisition of these skills and that (2) the use of phonological mediation may allow the construction of the orthographic lexicon. In January and June, first graders (n = 57) were required to read and spell items designed to assess the variables of regularity, graphemic complexity, frequency, lexicality and analogy. The findings of the January session partially corroborated the first hypothesis as a regularity effect, but no frequency effect and no word superiority, were found both in reading and spelling. The main contradictory finding was the presence, in early reading only, of a facilitative effect of analogy. The changes in the frequency and the lexicality effects between the two sessions in reading and in spelling indicated that the children were able to rapidly construct an orthographic lexicon. However, this procedure did not entirely replace phonological mediation since a regularity effect and regularization errors were observed and increased between sessions. The second hypothesis was supported as relationships were found to exist between early phonological skills and subsequent orthographic skills. Finally, we observed that French children were using graphemes (not only letters), in the early stage of reading, and, to a lesser extent, in the early stage of spelling. The findings are discussed in the context of developmental models of reading and spelling.

Learning disabilities and adolescent suicide.

To investigate the hypothesis that learning disabilities (LD) play a part in adolescent suicide, all available suicide notes (n = 27) from 267 consecutive adolescent suicides were analyzed for spelling and handwriting errors. The suicide notes were dictated to adolescents with LD and adolescent non-LD controls. The results showed that 89% of the 27 adolescents who committed suicide had significant deficits in spelling and handwriting that were similar to those of the adolescents with LD, and they were significantly more impaired than the non-LD adolescents and older adults (65 and older) who had committed suicide in the same time period and in the same geographical area.

Reading and language in 9- to 12-year olds prenatally exposed to cigarettes and marijuana.

Facets of reading and language were examined in 131 9- to 12-year-old children for whom prenatal exposure to marijuana and cigarettes had been ascertained. The subjects were from a low-risk, predominantly middle class sample who are participants in an ongoing longitudinal study. Discriminant Function Analysis revealed a dose-dependent association that remained after controlling for potential confounds, between prenatal cigarette exposure and lower language and lower reading scores, particularly on auditory-related aspects of this latter measure. The findings are interpreted as consistent with earlier observations of an association between cigarette smoking during pregnancy and altered auditory functioning in the offspring. Similarities and differences between the reading observations and dyslexia are discussed. Maternal prenatal passive smoke exposure did not appear to contribute to either the language or reading outcomes at this age but postnatal secondhand smoke exposure by the child was associated with poorer language scores. Prenatal marijuana exposure was not significantly related to either the reading or language outcomes.

The development of phonological rules and visual strategies in average and poor spellers.

To investigate the development of phonological and visual skills used in spelling, 420 children between the ages of 6 and 16 completed the spelling dictation test of the Wide Range Achievement Test-Revised. The misspellings were scored for phonological as well as visual accuracy using a constrained (inclusion of position cues) and an unconstrained system. Poor spellers made fewer phonologically accurate and fewer visual matches than age-matched average spellers. Poor spellers produced significantly more misspellings that were close visual matches to the target word and fewer phonologically unconstrained misspellings than spelling grade-matched average spellers. The groups did not differ in their production of phonologically constrained misspellings. Average spellers used a phonological approach more frequently than a visual approach, while the reverse pattern was true for poor spellers. When phonological rules are less well developed, then individuals are more likely to use orthographic skills.

Preference for visual scanning strategies versus phonological rehearsal in university students with reading disabilities.

This study investigated strategic preferences for visual scanning versus phonological rehearsal for recognizing words, pronounceable letter strings, and symbol strings by university students with reading disabilities (RD). Forty-seven subjects participated in this study: 20 students with reading disabilities who reported current difficulties in reading, as well as problems in learning to read at an early age; 15 students with learning disabilities (LD) who reported current difficulties in learning in areas other than reading but did not recall difficulties in learning to read; and 12 nondisabled readers (NR). The main dependent measures were response latency on a matching task for words, nonwords, and symbol strings, and posttest verbal reports of strategies used. Results showed that (a) most subjects in the NR group consistently used a strategy of phonological rehearsal for both words and nonwords, whereas most subjects with RD consistently used a strategy of visual scanning for these tasks, and (b) the NR group responded significantly faster than did the RD and LD groups to all three types of stimuli. The results indicate differences between university students who have a reading disability and nondisabled readers in strategic preferences for processing phonological information, with a clear preference by the former for using visual scanning rather than phonological rehearsal in matching tasks of words and nonwords.

Subtypes of learning disabilities in adolescents and adults.

This study tested the hypothesis that a classification scheme developed for the subtyping of learning disabilities in children, when applied to a population of adolescents and adults, would result in subtyping into discrete and relatively homogeneous groups in terms of cognitive functioning and achievement. We compared three groups, arithmetic disability (AD), reading disability (RD), and reading and arithmetic disabilities (RAD), among themselves and with a comparison group with normal achievement (NA) on a variety of cognitive and achievement measures. The main findings were as follows: (a) Each of the groups differed significantly from the others on tests of reading, spelling, memory, and other cognitive measures; (b) both the RD and RAD groups showed a deficit in phonological processing, vocabulary, spelling, and STM; (c) the AD group performed similarly to the NA group on pseudoword reading and phonological processing, but did more poorly than the NA group on word reading and vocabulary; (d) on many tasks the RAD group performed more poorly than the other groups; and (e) the AD and RAD groups performed more poorly than the NA and RD groups on a visual-spatial task. This study demonstrated the validity of this classification scheme for the subtyping of learning disabilities in adolescents and adults.

Is the Continuous Performance Task a valuable research tool for use with children with Attention-Deficit-Hyperactivity Disorder?

The Continuous Performance Task (CPT) has become a popular research tool used to distinguish children with Attention-Deficit-Hyperactivity Disorder (ADHD) from their normal peers. Whether hyperactive children have a vigilance decrement remains an ongoing controversy. The theoretical basis of the CPT and variables known to influence performance are examined in order to interpret the inconsistencies evident in the research. Studies which employed the CPT in order to examine the possibility of sustained attention deficits in children with ADHD will be reviewed. The results are examined in light of group selection criteria, task variables and situational and external variables. It is concluded that there is no compelling evidence for a sustained deficit in ADHD children. An alternative theoretical model for understanding the results of CPT performance in ADHD children is provided.

An evaluation of the discrepancy definition of dyslexia.

The purpose of this study was to determine whether children with dyslexia, that is, children whose reading levels were significantly lower than would be predicted by their IQ scores, constituted a distinctive group when compared with poor readers, that is, children whose reading scores were consistent with their IQ scores. The performance of children with dyslexia, poor readers, and normally achieving readers was compared on a variety of reading, spelling, phonological processing, language, and memory tasks. Although the children with dyslexia had significantly higher IQ scores than the poor readers, these two groups did not differ in their performance on reading, spelling, phonological processing, or most of the language and memory tasks. In all cases, the performance of both reading disabled groups was significantly below that of nondisabled readers. The findings were similar whether absolute difference or regression scores were used. Reading disabled children, whether or not their reading is significantly below the level predicted by their IQ scores, experience significant problems in phonological processing, short-term and working memory, and syntactic awareness. On the basis of these data, there does not seem to be a need to differentiate between individuals with dyslexia and poor readers. Both of these groups are reading disabled and have deficits in phonological processing, verbal memory, and syntactic awareness.

Language intervention with children who have developmental delays: effects of an interactive approach.

The interactive model of language intervention instructs parents to use techniques that promote reciprocal social interactions and facilitate the development of communication and language abilities. In this evaluation study, 32 mothers and their preschool-age children with developmental delays were randomly assigned to treatment and control (delayed treatment) groups. Consistent with the interactive model, mothers in the treatment group became more responsive, less directive, and provided clearer linguistic models. Furthermore, these changes were maintained for at least 4 months after intervention, and involvement in the parent-centered intervention program did not increase maternal stress. More important, these changes were accompanied by concomitant increases in children's use of vocal turns. Contrary to predictions, developmental improvements in children's communicative and linguistic abilities were comparable in both groups. Findings suggest that an interactive model may afford a useful adjunct to other intervention approaches by instructing parents on how to promote children's use of existing abilities, but an interactive model may have no effect on language acquisition of at least some children with developmental delays.

A dose-response analysis of the effects of methylphenidate on the peer interactions and simulated classroom performance of ADD children with and without conduct problems.

To examine the social effects of methylphenidate, groups of 15 attention-deficit disordered boys with (ADD) and 15 ADD boys without conduct problems (ADD/CP) were paired with normal peers. ADD and ADD/CP children showed a different pattern of responses to methylphenidate. While on task behavior in ADD/CP dyads increased at 0.15 mg/kg doses, increases in ADD dyads were not observed until doses reached 0.50 mg/kg. Although controlling interaction in ADD children decreased at 0.15 mg/kg, the controlling behavior of ADD/CP children did not decline at either dose. Peers of both ADD and ADD/CP children showed reciprocal declines in controlling behavior. In both free play and cooperative task situations, 0.15 mg/kg increased social interaction in ADD boys and decreased social interaction in ADD/CP boys.

Left ear dichotic listening performance on consonant-vowel combinations and digits in subtypes of reading-disabled children.

Twenty reading comprehension-disabled (CD) and 20 reading comprehension and word recognition-disabled (CWRD), right-handed male children were matched with 20 normal-achieving age-matched controls and 20 normal-achieving reading level-matched controls and tested for left ear report on dichotic listening tasks using digits and consonant-vowel combinations (CVs). Left ear report for CVs and digits did not correlate for any of the groups. Both reading-disabled groups showed lower left ear report on digits. On CVs the CD group showed a high left ear report but only when there were no priming precursors, such as directions to attend right first and to process digits first. Priming effects interfered with the processing of both digits and CVs. Theoretically, the CWRD group seems to be characterized by a depressed right hemisphere, whereas the CD group may have a more labile right hemisphere, perhaps tending to overengagement for CV tasks but vulnerable to situational precursors in the form of priming effects. Implications extend to (1) subtyping practices in research with the learning-disabled, (2) inferences drawn from studies using different dichotic stimuli, and (3) the neuropsychology of reading disorders.

Learning disability, inferential skills, and postfailure reflectivity.

Children with learning disabilities (LD) were compared with normally achieving children (NA) on two aspects of problem solving: inferential skills and response to errors in an academic content-free task. We tested 33 normally achieving children and 69 children with LD, aged 7 years 10 months to 16 years 4 months, on the PAR (PAttern Recognition) task, a computer-based, self-paced learning sequence. The children with LD were subtyped in two different ways: first, as children with only an arithmetic disability (AD), or with both arithmetic and word-recognition disabilities (AD/WRD); and second, as children with LD and attention deficit disorder (ADD), or LD without ADD. Results showed that on inferential skills, children with LD (without subtyping), children with AD/WRD, and children with LD with and without ADD scored significantly lower on the PAR task than children in the NA group. Also, an interaction was found between the NA and LD (without subtyping) groups and age, whereby children with LD improved their scores on PAR with age significantly more than normally achieving children. On attention to errors, children with both arithmetic and word-recognition disabilities scored significantly lower than children with only arithmetic disability or NA. It appears that the meta-cognitive skill of monitoring errors may be a major source of difficulty in problem solving for children with both arithmetic and word-recognition disabilities.