Autistic spectrum disorder: a child population profile

This study analyses the prevalence of ASD, comorbidity, educational provision and ability in autistic children in a single health district, born between 1983 and 1996. The number of recorded diagnoses doubled over a 4 year period. This appeared to be due to greater recognition of ASD in more able children, in children initially presenting with ADHD, and possibly in females. ADHD accounted for a substantial proportion of comorbidity. Age at diagnosis appeared to be related to school placement. Cognitive ability levels ranging from more than three standard deviations below the mean to more than one standard deviation above the mean were found in the moderate and severe learning difficulty school population as well as in the mainstream population. Exceptionally low levels of verbal ability were present in a high proportion of mainstream pupils. Measured levels of cognitive function show poor relationship with actual educational placement.

Behavioral manifestations of autism in the first year of life

In the interest of more systematically documenting the early signs of autism, and of testing specific hypotheses regarding their underlying neurodevelopmental substrates, we have initiated a longitudinal study of high-risk infants, all of whom have an older sibling diagnosed with an autistic spectrum disorder. Our sample currently includes 150 infant siblings, including 65 who have been followed to age 24 months, who are the focus of this paper. We have also followed a comparison group of low-risk infants. Our measures include a novel observational scale (the first, to our knowledge, that is designed to assess autism-specific behavior in infants), a computerized visual orienting task, and standardized measures of temperament, cognitive and language development. Our preliminary results indicate that by 12 months of age, siblings who are later diagnosed with autism may be distinguished from other siblings and low-risk controls on the basis of: (1) several specific behavioral markers, including atypicalities in eye contact, visual tracking, disengagement of visual attention, orienting to name, imitation, social smiling, reactivity, social interest and affect, and sensory-oriented behaviors; (2) prolonged latency to disengage visual attention; (3) a characteristic pattern of early temperament, with marked passivity and decreased activity level at 6 months, followed by extreme distress reactions, a tendency to fixate on particular objects in the environment, and decreased expression of positive affect by 12 months; and (4) delayed expressive and receptive language. We discuss these findings in the context of various neural networks thought to underlie neurodevelopmental abnormalities in autism, including poor visual orienting. Over time, as we are able to prospectively study larger numbers and to examine interrelationships among both early-developing behaviors and biological indices of interest, we hope this work will advance current understanding of the neurodevelopmental origins of autism.

Exploring the gap between knowledge and behavior: a qualitative study of clinician action following an educational intervention

PURPOSE

Many medical education interventions improve clinicians' knowledge but fail to change behavior. The authors exposed this knowledge-behavior gap through standardized clinical interactions, thus allowing in-depth exploration of the contributing factors.

METHOD

A typical evidence-based educational intervention in one clinical domain (early signs of autism) was administered to family medicine residents at the University of Toronto in 2001-02, and change in knowledge was assessed through a multiple-choice test. Six to eight weeks later, participants' relevant knowledge was documented, and their clinical behavior was observed during four interactions with standardized patients. Factors producing a knowledge-behavior discrepancy were then explored using semistructured interviews, which were audiotaped, transcribed, and analyzed using grounded theory methods.

RESULTS

Half of participants demonstrated varying degrees of knowledge-behavior gap. Eight main rationalizations (relationships, patient agenda, knowledge deficit, clinical style, means to an end, ideals, autism stigma, and systems barriers) were used to justify choices of clinical behavior, and the same rationalizations were used to justify opposite choices of behavior. Two conditions that promote clinical action based on knowledge (level of certainty and sense of urgency) were identified.

CONCLUSION

The knowledge-behavior gap was exposed and factors reported to influence clinicians' decisions about whether to implement new knowledge were elicited. That identical rationalizations were used to justify opposite behaviors implies these factors may not be behavioral determinants. Sense of urgency and level of certainty promote clinical action based on knowledge; focusing on these may increase the impact of education on practice.

A systems neuroscience approach to autism: biological, cognitive, and clinical perspectives

Autism is a behaviorally defined disorder characterized by a broad constellation of symptoms. Numerous studies directed to the biological substrate demonstrate clear effects of neurodevelopmental differences that will likely point to the etiology, course, and long-term outcomes of the disorder. Consistently replicated research on the neural underpinnings of autism is reviewed. In general, results suggest several main conclusions: First, autism is a heterogeneous disorder and is likely to have multiple possible etiologies; second, structural brain studies have indicated a variety of diffuse anatomical differences, reflective of an early developmental change in the growth or pruning of neural tissue, rather than localized lesions; similarly, neurochemical studies suggest early, neuromodulatory discrepancies rather than gross or localized abnormalities; and finally, there are a number of limitations on studies of brain activity that to date preclude definitive answers to questions of how the brain functions differently in autism. The large number of active research programs investigating the cognitive neuroscience of autism spectrum disorders, in combination with the exciting development of new methodologies and tools in this area, indicates the drama and excitement of work in this area.

Autism spectrum disorders: early detection, intervention, education, and psychopharmacological management

Our understanding and treatment of children with autism have changed dramatically since Leo Kanner first formally documented the disorder in 1943. With reference to the historical context, this paper reviews recent research addressing 4 major issues: early detection, intervention, education, and psychopharmacological management of children with autism and related (autistic) spectrum disorders (hereafter, "autism"). We conclude from our review of the evidence that, in the absence of additional, more compelling data, the clinical usefulness of existing screening instruments remains questionable. However, the potential importance of such research is underscored by the clear benefits of early behavioural intervention: despite differences in orientation, outcomes for children with autism can be significantly enhanced with early intensive intervention. Although many questions remain (notably, What are the critical therapeutic components? For whom? For what domains of development? For what level of intensity and duration?), interventions shown to be effective are all carefully planned, engineered, monitored, and designed to target specific skill domains. Including children with autism in regular classes within the public school system poses several challenges, the most pressing of which is the large number of school personnel who need to be trained in evidence-based teaching and behavioural management practices. Finally, psychotropic drugs may help to reduce some symptoms, but they are neither curative nor a substitute for other forms of support and intervention.

Early Identification of and Intervention for Infants and Toddlers Who Are at Risk for Autism Spectrum Disorder

Providing intensive early intervention is critical to maximizing outcomes for children with autism spectrum disorder (ASD), and evidence suggests that the earlier intervention can begin, the better the outcome. The first purpose of this article is to review the earliest indicators of ASD in very young children—social and communication impairments—which have important implications for early identification. The second purpose is to review evidence-based intervention practices for children with ASD and to develop a set of guiding principles for providing intervention for infants and toddlers who are at risk for ASD. Issues that are delineated include providing intervention in natural environments, supporting families in early intervention, and embedding intervention in daily routines.

Parental identification of early behavioural abnormalities in children with autistic disorder

The aim of the study was to identify early behavioural abnormalities in children later diagnosed with autistic disorder. Accurate identification of such deficits has implications for early diagnosis, intervention and prognosis. The parents of 153 children with autistic disorder completed a questionnaire asking them to describe early childhood behaviours of concern and to recall the age of onset. Core deficit-linked behaviours were then identified and the ontogeny of their development was noted. Behaviour categories were: (1) gross motor difficulties, (2) social awareness and play deficits, (3) language and communication difficulties, and (4) unusual preoccupations. The findings supported the notion that the nature and prevalence of these deficits depend on age. Consistent with past research, there was a significant interval between parents first noticing abnormalities and the making of a definitive diagnosis. The implications for this delay are discussed.

The disclosure of a diagnosis of an autistic spectrum disorder: determinants of satisfaction in a sample of Scottish parents

Satisfaction with disclosure of the diagnosis of an autistic spectrum disorder was investigated using a self-report questionnaire completed by 126 parents. On a rating of satisfaction, 55 percent indicated that they were satisfied or very satisfied with the disclosure. Parents were more likely to be satisfied if they gave positive ratings to the manner of the professional and the quality of the information provided; if they had been given written information and the opportunity to ask questions; and if their early suspicions had been accepted by professionals. These factors were combined into a global index of satisfaction; those gaining higher scores were more likely to have been given the diagnosis of Asperger syndrome (as opposed to autism), to have had a definite diagnosis, and to have children who were not currently in an educational placement. These results underline the importance of the interaction between parent and professional during the disclosure interview.

How well does early diagnosis of autism stand the test of time? Follow-up study of children assessed for autism at age 2 and development of an early diagnostic service

Twenty children who presented with severe and communication difficulties at age 2 underwent a comprehensive assessment for autism, and were reassessed at age 4-5. In common with other recent studies, diagnosis of autistic spectrum disorders at age 2 was found to be reliable and stable. The communication and social skills of the children showed little change overall by the second assessment. However, children whose scores deteriorated in the social domain tended to have presented initially with more significant behaviour problems. Few repetitive behaviours were observed at age 2, whereas these were more apparent by age 4-5. The finding that early diagnosis of autism is reliable and stable has led to the development of an early diagnostic service in Southampton, which is described. The importance of early diagnosis is that it opens the door to early intervention programmes, which in turn prevent many problems from occurring in later life.

Prevalence of autism in a US metropolitan area

CONTEXT

Concern has been raised about possible increases in the prevalence of autism. However, few population-based studies have been conducted in the United States.

OBJECTIVES

To determine the prevalence of autism among children in a major US metropolitan area and to describe characteristics of the study population.

DESIGN, SETTING, AND POPULATION

Study of the prevalence of autism among children aged 3 to 10 years in the 5 counties of metropolitan Atlanta, Ga, in 1996. Cases were identified through screening and abstracting records at multiple medical and educational sources, with case status determined by expert review.

MAIN OUTCOME MEASURES

Autism prevalence by demographic factors, levels of cognitive functioning, previous autism diagnoses, special education eligibility categories, and sources of identification.

RESULTS

A total of 987 children displayed behaviors consistent with Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria for autistic disorder, pervasive developmental disorder-not otherwise specified, or Asperger disorder. The prevalence for autism was 3.4 per 1000 (95% confidence interval [CI], 3.2-3.6) (male-female ratio, 4:1). Overall, the prevalence was comparable for black and white children (black, 3.4 per 1000 [95% CI, 3.0-3.7] and white, 3.4 per 1000 [95% CI, 3.2-3.7]). Sixty-eight percent of children with IQ or developmental test results (N = 880) had cognitive impairment. As severity of cognitive impairment increased from mild to profound, the male-female ratio decreased from 4.4 to 1.3. Forty percent of children with autism were identified only at educational sources. Schools were the most important source for information on black children, children of younger mothers, and children of mothers with less than 12 years of education.

CONCLUSION

The rate of autism found in this study was higher than the rates from studies conducted in the United States during the 1980s and early 1990s, but it was consistent with those of more recent studies.

Race differences in the age at diagnosis among medicaid-eligible children with autism

OBJECTIVE

To examine racial differences in the age at which Medicaid-eligible children first receive an autistic disorder (AD) diagnosis and to examine time in mental health treatment until an AD diagnosis was received.

METHOD

Philadelphia Medicaid specialty mental health claims identified 406 children who received services in 1999 for AD. Claims from 1993-1999 were used to identify the date of first mental health visit, first receipt of AD diagnosis, and number of visits occurring between those dates. Linear regression was used to examine the relationship among race, age at first diagnosis of AD, time in mental health treatment, and number of visits until the diagnosis was made.

RESULTS

On average, white children received the AD diagnosis at 6.3 years of age, compared with 7.9 years for black children (p <.001). White children entered the mental health system at an earlier age (6.0 versus 7.1 years, p =.005); however, after adjusting for age, sex, and time eligible for Medicaid, black children required more time in treatment before receiving the diagnosis.

CONCLUSIONS

Important disparities exist in the early detection and treatment of autism. These disparities may be the result of differences in help-seeking, advocacy and support, and clinician behaviors.

Supporting families of preschool children with autism: what parents want and what helps

This paper describes a local education authority project to provide support to the families of preschool children with autistic spectrum disorders. As part of an evaluation study, all parents were interviewed when their children entered full-time education and left the service's caseload. The report outlines key findings regarding levels of satisfaction with the service provided and describes parental responses to the different components of the support offered. All parents rated the input of the support worker as 'very useful'. Parents particularly valued the following: support to 'make sense' of their child's development and needs; practical strategies for facilitating language and engaging in interactive play; and support to the nurseries and playgroups attended by their children. The interviews also looked at parents' experience of diagnosis and their needs in the immediate aftermath. Key implications of these findings, and of this model of service delivery, are also discussed.

Screening young people for autism with the developmental behavior checklist

OBJECTIVE

To determine whether a subset of items from the Developmental Behavior Checklist (DBC) could be selected to construct a reliable autism screening tool.

METHOD

A 29-item scale-the Developmental Behavior Checklist-Autism Screening Algorithm (DBC-ASA)-was developed by using items from the DBC and evaluated in a sample comprising 180 children who met criteria for autism and 180 controls matched for age, sex, and IQ range.

RESULTS

This study found that the DBC-ASA has good validity in discriminating young people (4-18 years) with autism and IQ ranging from normal to severe intellectual disability from others using a cutoff score of 17.

CONCLUSION

The DBC-ASA is an effective autism screening questionnaire for at-risk young people, including those with intellectual disability.

Brief report: prevalence of autism spectrum conditions in children aged 5-11 years in Cambridgeshire, UK

The study aimed to establish prevalence of the broader autistic spectrum, including Asperger syndrome, in 5- to 11-year-olds in Cambridgeshire, UK. Cases of diagnosed autism spectrum condition (ASC) in children who were in Cambridgeshire schools and aged between 5 and 11 years on 31 December 1999 were sought using public records, screening instruments, educational psychology and special educational needs coordinator (SENCO) records. We report a prevalence of ASC in the age group 5-11 years of almost 0.6 percent (57 in 10,000). This is 11 times higher than the rate of classic autism but in line with other recent national and international rates for the broader spectrum. In the responding mainstream schools the prevalence was 0.33 percent. In the responding special school population it was 12.5 percent. The overall sex ratio of the children with ASC replicated findings for classical autism of 4:1 (M:F), but in those children being educated in mainstream schools the sex ratio was 8:1 (M:F).

Early intervention system for preschool children with autism in the community: the DISCOVERY approach in Yokohama, Japan

The article reports on DISCOVERY, a conceptual model for a clinical system of early detection and early intervention in cases of autism that has been implemented inYokohama, Japan. The minimal requirements for this system are subsystems dealing with detection, diagnosis and intervention. Specific issues involving early diagnosis that complicate the design of the system are the seemingly contradictory considerations of early versus precise diagnosis, the undifferentiated recognition of a child's disorder on the part of the parents, and the difficulty of establishing cooperative working relationships among related facilities. To overcome these issues, an 'interface' linking con secutive subsystems is emphasized in the DISCOVERY model. A clinical system based on this model has been developed in Yokohama. This system not only benefits clinical performance, but will also add significantly to research on autism.

Evaluation of adverse effects of vaccines: the case-control approach

When the hypothesis of a link between vaccination and a possible adverse outcome arises, further investigation is required to confirm or refute the suspicion. Given the rarity of most serious adverse effects, a case-control approach will often be chosen. This paper discusses aspects of the design, analysis and interpretation of case-control studies to evaluate vaccine adverse effects. Potential biases (and how to minimise such biases) in the selection of cases and assessment of vaccine exposure and the potential for confounding are discussed. Finally the increasing use of electronic databases in the evaluation of vaccine adverse effects is considered.

Prevalence of childhood disintegrative disorder

The prevalence of childhood disintegrative disorder (CDD) is unknown. In this study, 32 epidemiological surveys of autism and pervasive developmental disorders published in English language journals since 1966 were reviewed. Four surveys yielded estimates for CDD ranging from 1.1 to 6.4 per 100,000 subjects. A pooled estimate across these four surveys is 1.7 per 100,000 (95 percent Confidence Interval: 0.6-3.8 per 100,000). The conclusion is that CDD is very rare and its prevalence is 60 times less than that for autistic disorder, assuming a prevalence of 10 per 10,000 for autism. If a rate of 30 per 10,000 is taken for all PDDs, only one child out of 175 children with a PDD diagnosis would, on average, meet criteria for CDD.

Developing a diagnostic and intervention package for 2- to 3-year-olds with autism: outcomes of the frameworks for communication approach

The aim of the research was to develop and evaluate a model of good practice which would make an explicit link between diagnosis and intervention, and so give parents a very clear rationale for the autism-specific yet individualized programme that they were carrying out. It employed an action research design, which essentially is responsive to participants, thus developing a user-friendly model of service. The programme was based on the developmental perspective that the pragmatics of language are the precursors of speech itself and enable both communication and relationship between child and parents. Since these are impaired in autism they should therefore be prioritized in early intervention. Ten children aged 1:10 to 2:9 at assessment, and with a diagnosis of autism, underwent an intervention based on home visits, modelling, workshops and written information, with parents as 'therapists' in naturally occurring situations. Within 18 months all children made substantial progress in social interaction and expressive communication, including gestural and verbal communication.

The CAST (Childhood Asperger Syndrome Test): preliminary development of a UK screen for mainstream primary-school-age children

The article describes a pilot and follow-up study of the preliminary development of a new tool to screen for Asperger syndrome (AS) and related social and communication conditions (the Childhood Asperger Syndrome Test, CAST) in children aged 4-11 years, in a non-clinical setting. In the pilot study, parents of 13 children with AS and of 37 typically developing children completed the CAST. There were significant differences between the AS and typical sample means. The pilot was used to establish preliminary cut-off scores for the CAST. In the main study, parents of 1150 primary-school-age children were sent the CAST, and 174 took part in the full data analysis. Results suggest that compared with other tools currently available, the CAST may be useful for identifying children at risk for AS and related conditions, in a mainstream non-clinical sample. Further research is ongoing.

Intensive behavioral treatment at school for 4- to 7-year-old children with autism. A 1-year comparison controlled study

This study was designed to evaluate 1 year of intensive treatment for 4- to 7-year-old children with autism. An independent clinician assigned children to either behavioral treatment (n = 13) or eclectic treatment (n = 12). Assignment was based on availability of personnel to supervise treatment and was not influenced by child characteristics or family preference. The two treatment groups received similar amounts of treatment (M = 28.52 hours per week at the child's school). Children in the behavioral treatment group made significantly larger gains on standardized tests than did children in the eclectic treatment group. Results suggest that some 4- to 7-year-olds may make large gains with intensive behavioral treatment, that such treatment can be successfully implemented in school settings, and that specific aspects of behavioral treatment (not just its intensity) may account for favorable outcomes.

Can the checklist for autism in toddlers differentiate young children with autism from those with developmental delays?

OBJECTIVE

The Checklist for Autism in Toddlers (CHAT) has been demonstrated to be sensitive to the presence of autism in otherwise normally developing 18-month-old children. However, its ability to differentiate autism from other significant developmental delays is unknown. This study examined this question.

METHOD

The CHAT was applied to a group of 44 children aged 2 and 3 years, rigorously diagnosed with autism or with other developmental problems.

RESULTS

By the original CHAT authors' criteria, the sensitivity and specificity of the CHAT were 65% and 100%, respectively. Slightly altering the criteria resulted in a sensitivity of 85% in the current group of children with developmental disabilities while maintaining specificity of 100%.

CONCLUSIONS

The current study is the first to demonstrate that the CHAT successfully discriminates 2-year-old children with autism from those with other developmental disorders. In addition, the increased sensitivity of the Denver Criteria in children with developmental disabilities may improve its usefulness as a screening tool for community-based early-diagnostic teams and general practitioners.

Prevalence of autism in a United States population: the Brick Township, New Jersey, investigation

OBJECTIVE

This study determined the prevalence of autism for a defined community, Brick Township, New Jersey, using current diagnostic and epidemiologic methods.

METHODS

The target population was children who were 3 to 10 years of age in 1998, who were residents of Brick Township at any point during that year, and who had an autism spectrum disorder. Autism spectrum disorder was defined as autistic disorder, pervasive developmental disorder-not otherwise specified (PDD-NOS), and Asperger disorder. The study used 4 sources for active case finding: special education records, records from local clinicians providing diagnosis or treatment for developmental or behavioral disabilities, lists of children from community parent groups, and families who volunteered for participation in the study in response to media attention. The autism diagnosis was verified (or ruled out) for 71% of the children through clinical assessment. The assessment included medical and developmental history, physical and neurologic evaluation, assessment of intellectual and behavioral functioning, and administration of the Autism Diagnostic Observation Schedule-Generic.

RESULTS

The prevalence of all autism spectrum disorders combined was 6.7 cases per 1000 children. The prevalence for children whose condition met full diagnostic criteria for autistic disorder was 4.0 cases per 1000 children, and the prevalence for PDD-NOS and Asperger disorder was 2.7 cases per 1000 children. Characteristics of children with autism in this study were similar to those in previous studies of autism.

CONCLUSIONS

The prevalence of autism in Brick Township seems to be higher than that in other studies, particularly studies conducted in the United States, but within the range of a few recent studies in smaller populations that used more thorough case-finding methods.

Profile of referrals for early childhood developmental delay to ambulatory subspecialty clinics

The objective of this study was to determine the profile and pattern of referral to subspecialty clinics of young children with suspected developmental delay together with the factors prompting their referral. All children under 5 years of age referred to either developmental pediatrics or pediatric neurology clinics at a single tertiary hospital over an 18-month period were prospectively identified. Standardized demographic and referral information were collected at intake, final developmental delay subtype diagnosed was identified, and referring physicians were surveyed regarding factors prompting referral. A total of 224 children met study criteria. There was a marked male preponderance (166/224), especially among those with either cognitive or language delay. Two delay subtypes, global developmental delay and developmental language disorder, accounted for two thirds of the diagnoses made. For slightly more than one third of the children (75/224), the delay subtype diagnosed following specialty evaluation was different from that initially suspected by the referring physician. A mean delay of 15.5 months was observed for the cohort as a whole between initial parental concern and specialty assessment. For referring physicians, the major factor prompting referral was the severity of the observed delay. The most important aspects of the specialty evaluation according to referral sources were the identification of a possible etiology and confirmation of delay. A profile of referrals and the rationale thereof for a cohort of children with suspected developmental delay is presented that, although locale specific, has implications for service provision and training.

Etiologic determination of childhood developmental delay

To determine the etiologic yield in young children with developmental delay referred to sub-specialty clinics for evaluation. Over an 18-month period, all children less than 5 years of age referred to the ambulatory pediatric neurology or developmental pediatrics clinics of the Montreal Children's Hospital for initial evaluation of a suspected developmental delay were enrolled. Features evident on history or physical examination were determined at intake as were the laboratory tests (and their rationale) requested by the evaluating physicians. Six months post initial assessment, detailed chart review was undertaken to determine if an etiology was found and the basis for such a determination. Bivariate and multivariate logistic regression was used to test for associations between factors present at intake and successful ascertainment of an underlying etiology. Two hundred and twenty-four children met study criteria. Etiologic yield varied across childhood developmental delay subtypes, and was 44/80 for global developmental delay [GDD] (55%), 13/22 for motor delay [MD] (59.1%), 3/72 for developmental language disorders [DLD] (4.2%), and 1/50 for autistic spectrum disorders [ASD] (2%). For GDD, the presence of historical features or findings on physical examination was associated with greater likelihood for successful etiologic determination with the following items significant in multiple logistic regression analysis; microcephaly, antenatal toxin exposure, focal findings. For MD, physical findings or the co-existence of a cerebral palsy symptom complex predicted a successful search for etiology. For both groups, the severity of the delay did not predict etiologic yield. For both groups, a small number of etiologic categories accounted for the majority of diagnoses made. Etiologic yield in childhood developmental delay is largely dependent on the specific developmental delay subtype. Paradigms for systematic evaluation of this common child health problem can be suggested, however they await validation.

Etiologic yield of autistic spectrum disorders: a prospective study

At present, the etiologic yield in community-derived samples of young children with an autistic spectrum disorder is not known. To address this question, all young children (under 5 years of age) referred for an initial assessment to ambulatory pediatric neurology or developmental pediatric clinics at a tertiary university center over an 18-month period for a suspected developmental delay were prospectively identified. Specific diagnostic testing was left to the discretion of the evaluating physician. In all, 50 children with an autistic spectrum disorder were assessed. Detailed history or physical examination was informative with respect to suggesting the possibility of an underlying etiology in a minority (10/50,20%). Genetic studies (FMR-1, karyotype), electroencephalography (EEG), and neuroimaging were carried out in a majority (42/50, 34/50, and 33/50, respectively) of the children, for the most part on a screening rather than an indicated basis (31/42, 34/34, and 28/33, respectively). Etiologic yield was low (1/50, 2%), with only a single child identified with a possible Landau-Kleffner variant on sleep EEG tracing. The results suggest an evaluation paradigm with reference to etiologic determination for young children with autistic spectrum disorder that does not presently justify metabolic or neuroimaging on a screening basis. Recurrence risk and treatment implications, however, suggest that strong consideration be given to genetic (FMR-1, karyotype) testing and EEG study despite a relatively low yield.

Research in brief: what do medical students know about autism?

Although recent research indicates the importance of early recognition and intervention for children with autism, it is clear that many families remain very dissatisfied with the diagnostic process. In order to improve this situation, it is essential that primary care practitioners, such as GPs, are fully aware of the core symptoms of autism. The present study reports on autism awareness amongst 250 medical students at different stages of their training. Differences between first-year and fourth-year students were compared with respect to their knowledge of various aspects of autism, including diagnosis, cause, symptomatology, treatment and outcome. Fourth-year students were significantly more likely to respond correctly to questions related to diagnostic criteria and core symptoms. However no significant differences were found between first-year and fourth-year students for other aspects, such as possible causes, IQ profiles, prognosis and treatment. These findings suggest that more emphasis needs to be placed on teaching medical students about autism if diagnosis and access to intervention are to be improved.

Technical report: the pediatrician's role in the diagnosis and management of autistic spectrum disorder in children

Autism and its milder variants are not rare. Most pediatricians will have the opportunity to provide a medical home for a child with autism. This technical report serves to complement and expand on the information in the accompanying policy statement to increase the pediatrician's fund of knowledge and comfort level in caring for children with autism. In so doing, it is anticipated that earlier diagnosis and referral for appropriate intervention will be possible and that this will, in turn, have a positive effect on long-term outcomes for children with autism and their families.

Epidemiology of autism in Singapore: findings of the first autism survey

The report describes the results of a survey conducted on 176 parents of children with autism in Singapore. The ages of the children ranged from 3 to 12 years. The survey focused on the child's background, behaviour problems and skill profile, the home and school situation as well as the linguistic and social background. It was noted that the Singapore population confirms the international distribution regarding a predominance of boys over girls and a low incidence of birth complications. A positive trend noted was the fact that 60% of the children were diagnosed before the age of 3 years. Discussion focuses on possible risk factors and psychosocial adversities for autism such as a high frequency of caregivers who are foreign maids, the use of multiple languages and the high level of punitive educational practices. The possible influence of psychosocial deprivation on child development is discussed.

A case-control study of autism and mumps-measles-rubella vaccination using the general practice research database: design and methodology

BACKGROUND

An association between mumps-measles-rubella (MMR) vaccination and the onset of symptoms typical of autism has recently been suggested. This has led to considerable concern about the safety of the vaccine.

METHODS

A matched case-control study using data derived form the United Kingdom General Practice Research Database. Children with a possible diagnosis of autism will be identified from their electronic health records. All diagnoses will be validated by a detailed review of hospital letters and by using information derived from a parental questionnaire. Ten controls per case will be selected from the database. Conditional logistic regression will be used to assess the association between MMR vaccination and autism. In addition case series analyses will be undertaken to estimate the relative incidence of onset of autism in defined time intervals after vaccination. The study is funded by the United Kingdom Medical Research Council.

DISCUSSION

Electronic health databases offer tremendous opportunities for evaluating the adverse effects of vaccines. However there is much scope for bias and confounding. The rigorous validation of all diagnoses and the collection of additional information by parental questionnaire in this study are essential to minimise the possibility of misleading results.

Autism and developmental receptive language disorder--a follow-up comparison in early adult life. II: Social, behavioural, and psychiatric outcomes

This paper focuses on general social functioning in two groups of young men, one with autism and one with developmental receptive language disorders, who were first assessed at the ages of 7-8 years. At that time, although matched for nonverbal IQ (mean 92-93) and expressive language, the Language group showed significantly fewer social and behavioural problems. At follow-up, when aged on average, 23 to 24 years, the Autism group continued to show significantly more impairments in terms of stereotyped behaviour patterns, social relationships, jobs, and independence. However, problems in all these areas were also common in the Language group. Many still lived with their parents, few had close friends or permanent jobs, and ratings of social interaction indicated abnormalities in a number of different areas. On a composite measure of social competence only 10% of the Language group was assessed as having severe social difficulties compared to 74% of the Autism group. Nevertheless, 65% were rated as having moderate social problems and only 25% were rated as being of near/normal social functioning. Two individuals in the Language group, but none in the Autism group, had also developed a florid paranoid psychosis in late adolescence. As in the follow-up of cognitive and linguistic functioning (see Mawhood et al., 2000, this volume, pp. 547-559), discriminant function analysis, which had clearly distinguished between the groups as children, now showed much greater overlap between them. Regression analysis indicated that although early language ability appeared to be related to outcome in the Autism group, there was little association between any measures of childhood functioning and prognosis in the Language group. Theoretically, these findings have implications for our understanding of the nature of autism and other pervasive language disorders, and of the relationship between them. Practically, they demonstrate the very persistent problems experienced by individuals with developmental language disorders, and their need for much greater help and support than is presently available.

Understanding children with autism: exploding the myths

The incidence of autism is increasing in both the USA and in Britain. There is still controversy over what causes autism and even greater controversy over selecting a preferred method of intervention and support (as there is no treatment for autism). Although there is now a general consensus that individuals may have a genetic predisposition to develop autism, it is also acknowledged that this may be off set by a range of environmental and/or biological factors. The understanding of the causation of autism is now considered in much the same way as we understand cerebral palsy, in that there can be a range of different reasons for causation and prevalence. This article, the first of two parts, will explore how an awareness and understanding of autism can enable nurses working with children with autism to provide more child-centred nursing care based on fact as opposed to stereotype and mythology surrounding autism. The second part will concentrate on adults with autism.

A screening instrument for autism at 18 months of age: a 6-year follow-up study

OBJECTIVES

A population of 16,235 children aged 18 months was screened using the Checklist for Autism in Toddlers (CHAT) to identify childhood autism (CA). Two further screening procedures were conducted at age 3 and 5 years. The population was followed up at age 7 years in order to establish the sensitivity, specificity, and positive predictive value of the instrument.

METHOD

A brief checklist assessing joint attention and pretend play behaviors was administered by primary health care practitioners when the children were 18 months old. Follow-up methods included screening through parents and health practitioners and checking medical and educational records.

RESULTS

Nineteen cases of CA were successfully identified by the CHAT at 18 months. At follow-up a total of 50 cases of CA were identified via all surveillance methods. Thus, the CHAT has a sensitivity of 38% and a specificity of 98% for identifying CA. The positive predictive value of the instrument was maximized by concentration on the highest-risk group. Repeated screening 1 month later increased the positive predictive value to 75% for identification of CA but reduced the sensitivity to 20%, although the specificity was close to 100%. The screen also identified cases of pervasive developmental disorder as well as children with language and other developmental disorders.

CONCLUSIONS

The CHAT can be used to identify cases of autism and related pervasive developmental disorders at 18 months of age. It is emphasized that the CHAT is not a diagnostic instrument but can identify potential cases of autism spectrum disorders for a full diagnostic assessment.