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David Hay

Publications and source records attributed to David Hay.

11 recordsLinked to original sources
PubMed2006

Osteonecrosis of the jaw and bisphosphonates--putting the risk in perspective.

Osteonecrosis of the jaw is a poorly understood condition that has recently been associated with the use of potent bisphosphonate treatment. The prevalence appears to be approximately 1-10% in patients with malignancy treated with very high doses of intravenous bisphosphonates. In Paget's disease and osteoporosis, where the doses of bisphosphonate used are an order of magnitude lower than the oncology dose, the prevalence appears to be much lower--probably less than 1 in 60,000. The aim of this article is to put the risks of osteonecrosis of the jaw into context with the benefits of bisphosphonate treatment in these clinical scenarios.

Aged↗
PubMed2006

Can autism, language and coordination disorders be differentiated based on ability profiles?

Children with autistic disorder (AD), mixed receptive-expressive language disorder (RELD), or developmental coordination disorder (DCD) have impairments in common. We assess which abilities differentiate the disorders. Children aged 3-13 years diagnosed with AD (n = 30), RELD (n = 30), or DCD (n = 22) were tested on measures of language, intelligence, social cognition, motor coordination, and executive functioning. Results indicate that the AD and DCD groups have poorer fine and gross motor coordination and better response inhibition than the RELD group. The AD and DCD groups differ in fine and gross motor coordination, emotion understanding, and theory of mind scores (AD always lower), but discriminant function analysis yielded a non-significant function and more classification errors for these groups. In terms of ability scores, the AD and DCD groups appear to differ more in severity than in kind.

Adolescent↗
PubMed2006

DCD and ADHD: a genetic study of their shared aetiology.

Previous studies have found that rates of attention deficit hyperactivity disorder (ADHD) and developmental coordination disorder (DCD) are very similar, both being approximately 7% in sample populations [Kadesjö, B., & Gillberg, C. (1999). Developmental coordination disorder in Swedish 7-year-old children. Journal of the American Academy of Child and Adolescent Psychiatry, 38, 820-828; Milberger, S., Faraone, S., Biederman, J., Testa, M., & Tsuang, M. (1996). New phenotype definition of attention deficit hyperactivity disorder in relatives for genetic analyses. American Journal of Medical Genetics, 67, 369-377]. The rate of comorbidity between the two has been found to be close to 50% [Barkley, R. (1990). Attention deficit hyperactivity disorder: A handbook for diagnosis and treatment. New York: Guilford Press]. Investigations into the comorbidity of the disorders points to a shared aetiology between them. The aim of the present investigation was to examine the extent to which the shared aetiology is due to common genetic factors to both disorders. We also investigated whether particular subtypes of each disorder were more linked than others. Mailed questionnaires were completed by parents (predominantly mothers) of 1285 twin pairs aged 5 and 16 years from the volunteer Australian Twin Registry (ATR). Included were a DSM-IV-based ADHD form, the alternative SWAN (Strengths and Weaknesses of ADHD Symptoms and Normal Behaviour scale) and the Developmental Coordination Disorder Questionnaire (DCDQ). Statistical analyses including structural equation modelling were carried out to explore the genetic factors of both disorders. The modelling showed a strong shared additive genetic component between most subtypes of ADHD and DCD to the subtypes of the other disorder. Analyses comparing the two ADHD measures showed an overlap of the symptoms captured by each measure but also significant differences. The DCD-fine motor and ADHD-Inattentive were most strongly linked using the DSM-IV based scale. On the SWAN scale the results were similar but the general coordination scale was also very strongly linked. Implications for the use of different assessment tools are discussed.

Adolescent↗
PubMed2006

Are abilities abnormally interdependent in children with autism?

We propose that stronger than usual correlations between abilities indicate which cognitive processes are impaired in autism. Study 1 compared partial correlations (controlling age) between intelligence and social cognition in children with autism (n = 18), mental retardation (MR; n = 34), or no psychological disorder (n = 37). Correlations were stronger in the autism group. Study 2 compared correlations between measures of perceptual organization and verbal comprehension, receptive and expressive language, fine and gross motor coordination, and theory of mind, emotion recognition, and emotion understanding abilities in children with autism (n = 30) or MR (n = 24) and in a large representative sample of children (n = 449). Results indicate that autism is marked by stronger correlations between all ability domains, and MR is marked by stronger correlations between motor coordination tasks and other ability measures.

Affect↗
PubMed2005

Using concept maps to optimize the composition of collaborative student groups: a pilot study.

AIM: The aim of this paper is to stimulate interest in the practical classroom application of concept mapping strategies as an approach that teachers can easily use to enhance collaborative learning. BACKGROUND: Concept mapping has been developed as a tool to support meaningful learning. However, much of the research literature fails to explain how concept maps might be most gainfully employed within the classroom. As a result, concept mapping is a tool that is under-used. METHODS: Students on a postgraduate teacher preparation programme for nurses were arranged in triads on the basis of the morphology of individually-produced concept maps for the topics of 'genetics' and 'pathogenic microbes'. They were arranged in heterogeneous triads to produce a consensus map for 'pathogenic microbes', and then in homogeneous triads to produce a consensus map for 'genetics'. The number of acceptable propositions found in their individual maps was compared with the number found in the consensus group maps, and gain scores were calculated for each participant. FINDINGS: Participants arranged in triads of individuals having very different knowledge structures were found to make a greater improvement than those arranged in triads composed of individuals with qualitatively similar knowledge structures. CONCLUSIONS: The study was undertaken with a very small sample and only looked at two topic areas. However, the findings support the idea that collaborative groups work most effectively when individuals within the group bring different perspectives to a problem, and that this perspective can be usefully identified within the classroom environment as variations in concept map morphology.

Concept Formation↗
PubMed2005

Characterizing the ADHD phenotype for genetic studies.

The genetic study of ADHD has made considerable progress. Further developments in the field will be reliant in part on identifying the most appropriate phenotypes for genetic analysis. The use of both categorical and dimensional measures of symptoms related to ADHD has been productive. The use of multiple reporters is a valuable feature of the characterization of psychopathology in children. It is argued that the use of aggregated measures to characterize the ADHD phenotype, particularly to establish its pervasiveness, is desirable. The recognition of the multiple comorbidities of ADHD can help to isolate more specific genetic influences. In relation to both reading disability and conduct disorder there is evidence that genes may be involved in the comorbid condition that are different from pure ADHD. To date, progress with the investigation of endophenotypes for ADHD has been disappointing. It is suggested that extending such studies beyond cognitive underpinnings to include physiological and metabolic markers might facilitate progress.

Attention Deficit Disorder with Hyperactivity↗
PubMed2004

The relationship between motor coordination, executive functioning and attention in school aged children.

Given the high level of comorbidity of attention deficit hyperactivity disorder (ADHD) and developmental coordination disorder (DCD), deficits in executive function (EF), shown to be present in children with ADHD, may also be implicated in the motor coordination deficits of children with DCD. The aim of this study was to explore the relationship between EF and motor ability. A sample of 238 children, 121 girls and 117 boys, aged between 6 and 15 years was recruited for this project. Motor ability was assessed using the McCarron Assessment of Neuromuscular Development (MAND), level of inattention using the Child Behavior Checklist (CBCL), and Verbal IQ (VIQ) was estimated using subtests of the WISC-III. A reaction time task and three EF tasks measuring response inhibition, working memory and the ability to plan and respond to goal-directed tasks were administered. It was found that motor ability significantly accounted for variance in tasks measuring speed of performance, whereas inattention appeared to influence performance variability. Despite past evidence linking poor motor ability with inattention, there was little overlap in the processes that are affected in children with motor coordination or attention problems.

Adolescent↗
PubMed2004

Is the discrepancy criterion for defining developmental disorders valid?

BACKGROUND: Most developmental disorders are defined by an achievement discrepancy in which achievement on one or more specific abilities is substantially less than a person's measured intelligence. We evaluated the validity of this discrepancy criterion by assessing parameters that determine variability across abilities and by assessing relationships between achievement discrepancies and behavioral disturbances. METHODS: Measures of intelligence, language, motor coordination, empathic ability, and attentional control were administered to a representative sample of 390 children aged 3 to 12 years. Parent ratings of child behavior were obtained. RESULTS: Results indicate that achievement discrepancies are a function of the correlation between ability measures, the shape of the ability distributions, and position on an index ability dimension. Discrepancies in achievement were not related to behavioral disturbance, but underachievement relative to age peers was invariably related to behavioral disturbance. CONCLUSIONS: We conclude that developmental disorders need to be redefined in ways that are consistent with how Mental Retardation is now defined, by (a) underachievements, (b) of defined magnitude, (c) using standardized measures, (d) with known relations to normal development, and (e) concurrent deficits on standardized measures of impaired function.

Age Factors↗
PubMed2003

Heterogeneity of admission history among patients with bipolar disorder.

BACKGROUND: Patients on a first admission for bipolar disorder often have a history of other psychiatric diagnoses for previous admissions. AIMS: The current study examines the time course and diagnoses of psychiatric admissions prior and subsequent to a first hospitalisation for a diagnosis of bipolar disorder. METHOD: The prior admission histories (over the period 1965-1989) of 1167 patients who had been hospitalised in state mental health facilities with their first admission with diagnosis of bipolar disorder between 1983 and 1989 were examined. RESULTS: A total of 542 (46.4%) patients had at least one previous hospitalisation with a psychiatric diagnosis other than bipolar disorder. Two prominent groups emerged; one group which had primarily a history of prior admissions with diagnoses of depression over 1-3 years, and a second which mainly had previous admissions for schizophrenia, over a period longer than for those with a primarily depressive history. The group with a history of schizophrenia was significantly younger and had a greater number of admissions prior to the first bipolar disorder diagnosis than the depression group. LIMITATIONS: This was a record-based study which did not examine cases which were not hospitalised. CONCLUSIONS: There appeared to be three distinct patterns of prior presentations in those patients admitted with a diagnosis of bipolar disorder.

Adult↗
PubMed2003

Small for gestational age as a predictor of behavioral and learning problems in twins.

The study examines the effects of being born small for gestational age (SGA) on rates of behavioral problems in twins and siblings, utilising data from the Australian Twin Study of disruptive behavior disorders in twins and their siblings. Participants were 3944 twins and their siblings who were assessed at two intervals three years apart. At the first assessment (1991), they ranged between 4 and 12 years of age. Items assessing Attention Deficit/Hyperactivity Disorder were based on DSM-III-R criteria (Time 1) and DSM-IV criteria (Time 2). Other measures included history of speech and reading therapy, demographic information and obstetric and neonatal history. Results indicated that both male and female twins, who were extremely growth restricted (small for gestational age up to the third percentile-WGA3) showed more inattention, and poorer speech and reading scores. The effects were greater for males. Male twins who were small for gestation age, up to the 10th percentile, were more likely to have a DSM-IV diagnosis of Inattention. Implications of these results included WGA3 male twins being at a "triple disadvantage" for subsequent behavioral and learning problems, in that being male, being a twin and being small for gestational age are all significant factors. Recommendations are made for early intervention for low birthweight male twins. The study is consistent with recent follow-up studies of very-low-birthweight singletons, indicating male disadvantage in cognitive outcome. While there is some genetic component to SGA, it does constitute a potentially major contribution to common environmental effects that must be considered in twin-based genetic analyses.

Child Behavior Disorders↗