This article was downloaded by:[ryerson University] On: 4 June 2008 Access Details: [subscription number 789542258] Publisher: Routledge Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House, 37-41 Mortimer Street, London W1T 3JH, UK To link to this article: DOI: 10.1080/09669760801892318 URL: http://dx.doi.org/10.1080/09669760801892318 International Journal of Early Years Education Publication details, including instructions for authors and subscription information: http://www.informaworld.com/smpp/title~content=t713425018 The role of early childhood professionals in the early identification of autistic disorder Maureen Samms-Vaughan a ; Lisa Franklyn-Banton a a Section of Child Health, Department of Obstetrics, Gynaecology and Child Health, University of the West Indies, Kingston, Jamaica Online Publication Date: 01 March 2008 To cite this Article: Samms-Vaughan, Maureen and Franklyn-Banton, Lisa (2008) 'The role of early childhood professionals in the early identification of autistic disorder', International Journal of Early Years Education, 16:1, 75 84 PLEASE SCROLL DOWN FOR ARTICLE Full terms and conditions of use: http://www.informaworld.com/terms-and-conditions-of-access.pdf This article maybe used for research, teaching and private study purposes. Any substantial or systematic reproduction, re-distribution, re-selling, loan or sub-licensing, systematic supply or distribution in any form to anyone is expressly forbidden. The publisher does not give any warranty express or implied or make any representation that the contents will be complete or accurate or up to date. The accuracy of any instructions, formulae and drug doses should be independently verified with primary sources. The publisher shall not be liable for any loss, actions, claims, proceedings, demand or costs or damages whatsoever or howsoever caused arising directly or indirectly in connection with or arising out of the use of this material.
International Journal of Early Years Education Vol. 16, No. 1, March 2008, 75 84 The role of early childhood professionals in the early identification of autistic disorder Maureen Samms-Vaughan* and Lisa Franklyn-Banton Section of Child Health, Department of Obstetrics, Gynaecology and Child Health, University of the West Indies, Kingston, Jamaica CIEY_A_289398.sgm 10.1080/09669760801892318 International 0966-9760 Original 2008 Taylor 16 1000000March MaureenSamms-Vaughan msamms@cwjamaica.com and & Article Francis (print)/1469-8463 Journal 2008 of Early (online) Years Education Autism is a pervasive developmental disorder defined by impaired social skills, impaired language development and stereotyped or repetitive behaviours. The increasing prevalence of autism worldwide has made this an important condition among professionals working with young children, including those in Jamaica. Early identification and intervention improves the outcome for autistic children. This article investigates the role of professionals working with young children in the early identification and intervention by reviewing the diagnostic process. A cross-sectional survey of 117 children diagnosed with autism at the University Hospital of the West Indies (UHWI) in Jamaica over a five-year period was undertaken. Data were collected retrospectively from hospital records on demographic characteristics, presenting features, professionals recommending referral, age of maternal concern and age at diagnosis. The mean age of maternal concern was 21.3 ± 10.9 months, but the mean age at diagnosis was 43.8 ± 17.8 months. The main behaviour resulting in parental concern was language development, occurring in some 85% of children. The majority of children (76.2%) were referred to the UHWI diagnostic centre by specialist medical personnel. First contact education and health sector professionals referred only 5.6% and 4.6% of children, respectively. Low socio-economic status was a significant factor affecting delay in diagnosis. The study has shown significant delays in diagnosis of autism, despite early concern by mothers. The study recommends general public education on the features of autism, as well as education targeted at first-contact health and education professionals. Professionals should also be educated on the use of simple screening tools and the referral process to the diagnostic centre, to reduce diagnostic delay. Keywords: autistic disorder, Jamaica Introduction Autism is the commonest of the pervasive developmental disorders, which are a group of conditions usually diagnosed in childhood. It is defined behaviourally by a triad consisting of impaired development of social skills, limitations in the use of interactive language and other forms of communication and repetitive and stereotypical patterns of behaviour (American Psychiatric Association 1994; American Academy of Pediatrics, Committee on Children with Disabilities 2001b). Over the past thirty years there has been an increase in the reported prevalence of autism throughout the world. Studies published before 1985 show prevalence rates of 2 per 10,000 children for the classic autistic disorder and 4 to5 per 10,000 children for the broader autistic spectrum of disorders (Merrick, Kandel, and Morad 2004). A recent meta-analysis reports the median rate for 11 surveys, conducted since 1989, to be 7 per 10,000 persons (Filipek, Accardo, and Ashwal 2000). *Corresponding author. Email: msamms@cwjamaica.com ISSN 0966-9760 print/issn 1469-8463 online 2008 Taylor & Francis DOI: 10.1080/09669760801892318 http://www.informaworld.com
76 M. Samms-Vaughan and L. Franklyn-Banton There has been much speculation as to the reasons for the increase in prevalence over the past thirty years. Wing et al. (Wing and Potter 2002) attribute the higher estimates to changes in diagnostic criteria, development of the concept of the wider autistic spectrum, different methods used in prevalence studies, growing awareness and knowledge among parents and professional workers and the development of specialist services. The possibility of a genuine rise in prevalence has also been entertained (Blaxill 2004). Regardless of the cause of the increased prevalence, autism is now recognised as a relatively common disorder among young children. Children with autism, as with many other developmental disorders, have the best outcomes when there is early identification and intensive intervention. Despite this knowledge, many autistic children are not identified at an early age. In the United States, families of children with autism report that they often make numerous attempts to attain a diagnosis and understanding of their children s difficulties, some as early as two years of age (Scambler, Rogers, and Wehner 2001). Howlin and Moore (1997) found that families in the United Kingdom (UK) often sought medical attention for their children by age two years from primary health care providers although their children did not receive a diagnosis of autism until they were six years of age on average. As Filipek described, a number of diagnostic steps may occur between the time that parents first raise concerns about their child to their primary health care provider, and the point at which a diagnosis of autism is finally made (Filipek et al. 1999). Shortening the time period between initial parental concern and diagnosis is an important goal to improve long-term outcome of children with autism. This has led to the development of screening tools for autism, the best known of which is the Checklist for Autism in Toddlers (CHAT). The CHAT is a 14-item questionnaire on children s behaviours designed to be administered to parents by a primary health care worker at 18 months of age. Using the CHAT, Baron-Cohen was able to predict children who later received a diagnosis of autism at 3.5 years (Baron-Cohen 1992; Baird, Charman, and Baron-Cohen 2000). The authors concluded that the presence of concerns elicited by administration of the CHAT questionnaire at 18 months carried an 83.3% risk of a diagnosis of autism (Baron-Cohen 1992; Baron-Cohen, Cox, and Baird 1996). Although the CHAT, when used by a community health nurse, was highly specific in excluding non-autistic children, its sensitivity for autistic spectrum disorders was only 38% and its positive predictive value was 29%. When used as a two-stage measure, with the second administration one month after the first, by a team experienced with autism, the positive predictive value rose to more than 75%. Young children and their parents most frequently come into contact with two first-contact professional groups: primary health care providers and educators. With the increasing prevalence, health professionals are therefore likely to be seeing more young children being brought for services because of parental concerns about their development and/or behaviour. Professionals in the education sector, who spend more time with children than their colleagues in the health sector, would likely be seeing the developmental and behavioural manifestations of the condition expressed in their classroom. Difficulty communicating with teachers and peers and social impairments, such as isolated play and failure to make eye contact, and repetitive and stereotyped play and behaviours in the classroom, would be noticed. Additionally, associated features of the condition, such as hyperactivity, aggression and self-injury, are likely to be disruptive to classroom routines. Finally, the astute teacher will easily identify the impaired cognitive development that occurs in two-thirds of children with autistic disorder (Filipak, Accardo, and Ashwal 2000). Early identification of autistic disorder has largely been considered the remit of the health professional, with little attention paid to the potential role of educators (American Academy of Pediatrics, Committee on Children with Disabilities 2001a,b). In Jamaica, where 96% of children aged three to six years are in pre-school, the role of educators in the early identification of autistic disorder may assume greater importance.
International Journal of Early Years Education 77 This article reviews the process of diagnosis of children with autistic disorder in Jamaica, with special reference to the roles that first-contact early childhood professionals in the health and education sector may play in impacting this process. Methodology Study design and case identification The study was a cross-sectional survey of children with autistic disorder. Children were identified from the public Child and Family Clinic for Developmental and Behavioural Disorders of Childhood and a private developmental and behavioural paediatric practice, both at the University Hospital of the West Indies (UHWI). The UHWI is the main teaching hospital of the University of the West Indies and is recognised as the main referral centre for children with autistic disorder. Referrals are received at the centre directly from medical, paramedical or education professionals. Parents who take their children directly to the centre without referral are also seen, after a screening and triage process. Inclusion and exclusion criteria Only children with a diagnosis of classic autistic disorder between the years 1999 and 2004 were included. Children falling into the broader group of autistic spectrum disorders, including the pervasive developmental disorders not otherwise specified, were excluded to ensure diagnostic accuracy. The five-year period was selected because there was a standardised assessment and diagnostic procedure in use in both private and public diagnostic facilities at this time. Data collection Data were collected retrospectively from hospital records using a survey sheet designed specifically for this purpose. Data collected included demographic data (age, gender, geographic location, socio-economic status), behaviours eliciting parental concern, age of child at time of parental concern, professional making referral and age of child at time of diagnosis. Geographic location was classified into categories of urban, suburban and rural, based on country definitions. Socio-economic status (SES) was determined by the profession of the mother; the mother was the main person who had provided information documented in health records. There were four SES categories: professional, skilled, unskilled and unemployed. Data analysis The statistical software package, SPSS version 11.0, was used to analyse the data. Prior to data analysis, data were reviewed for range and logic errors. A missing value analysis was also carried out to identify data gaps. Categorical data were analysed using frequencies and the chi-squared test. Continuous data were analysed using analysis of variance. A p value of less than 0.05 was considered significant. Results A total of 145 children with a diagnosis of autism were identified, with 67 (46.2%) of these cases from the public Child and Family Clinic. Of the 145 cases identified, 28 records could not be located. Therefore, 117 children (81% of the total) were included in the study. Of these, 104 (88.9%) were male and the remaining 11.1% (n=13) females. This represents an 8:1 male to female ratio. Some 11.9% of mothers were employed in professional occupations, with 57.8% in skilled occupations, 6.4% in unskilled occupations and 23.9% unemployed.
78 M. Samms-Vaughan and L. Franklyn-Banton Table 1. Behaviours causing maternal concern. Parental concern Parental concern was investigated by analysing data collected on the behaviours eliciting concern and the age at which these behaviours occurred. As mothers were in almost all cases the persons attending the diagnostic services at the UHWI, with their children, parental concern was essentially maternal concern. The behaviour that was of greatest concern to mothers was delayed language development, occurring as an isolated reason in 48.6% of children (Table 1). This was followed by regression in language skills, occurring in 13.5% of children, where attainment of early language milestones were initially age appropriate only to be followed by subsequent loss of achieved milestones. In total, 85.5% of parents were concerned about some aspect of language development. This compares with 14.4% and 9.9% expressing concern about behaviour and social skills, respectively. The mean age of concern was 21.3 ± 10.9 months, with a mode of 24.0 months. There was a significant difference in age of concern by gender, with the mean age of concern for boys being 20.6 months, some 6.9 months earlier than the age of concern for girls (p<0.05). Urban parents had a mean age of concern some 2.5 months earlier than rural parents, but this was not statistically significant. Figure 1 shows the variation in mean age of concern by socio-economic status; this was statistically significant at the p<0.05 level. Figure 1. Mean age of maternal concern by socio-economic status. Frequency Percentage Delayed language development 54 48.6 Regression in language skills 15 13.5 Behavioural and learning difficulties 9 8.1 Delayed language development and behavioural problems 7 6.3 Delayed motor and language development 7 6.3 Impairment in receptive language 6 5.4 Delayed language development and poor social interaction 6 5.4 Impaired social skills 3 2.7 Delayed motor development 2 1.8 Regression of social skills 2 1.8 Total 111 100.0 Sources of referral Table 2 shows the sources of referral to the specialist public or private clinic for diagnosis. There were four categories of referral sources; the first category of medical personnel included specialists and primary care medical professionals at private and public institutions across Jamaica. Paramedical personnel included speech therapists, audiologists and occupational therapists at public and private institutions throughout Jamaica. The third category included educational institutions of all types, and the final category represented individuals who sought direct contact with diagnostic services at the UHWI. Medical professionals referred 88 children (80.8%). Private pediatricians referred 66 children (75.0%), with other secondary or tertiary care services provided by paediatric outpatient departments, other hospitals or psychiatrists accounting for a further 15.6% of referrals. Primary care health professionals, general practitioners and health centre staff accounted for only 4.6% of referrals. Paramedical services represented the second highest referral source, with a total of
International Journal of Early Years Education 79 Mean Age of Concern 26 24 22 20 18 17.3 19.8 24.8 25.5 16 professional skilled unskilled Maternal Socio-Economic Status unemployed Figure 1. Mean age of maternal concern by socio-economic status. Table 2. Sources of referral to diagnostic centre. Referral source Frequency Percentage Medical personnel 88 80.8 Paediatrician 66 60.6 Pediatric outpatient department staff 10 9.2 Health centre staff 2 1.8 General practitioner 3 2.8 Child psychiatrist 1.9 Other hospital 6 5.5 Paramedical Personnel 13 11.9 Speech therapist 7 6.4 Audiologist 1.9 Disability institutions 5 4.6 Educational services 6 5.6 School for mentally impaired 3 2.8 School teacher 3 2.8 Self-referral 2 1.8 Total 109 100.0
80 M. Samms-Vaughan and L. Franklyn-Banton Table 3. Age at diagnosis by source of referral. Referral source N Mean Std. Deviation Medical personnel 78 46.4 27.1 Paramedical personnel 13 47.6 20.2 Educational services 6 63.3 44.7 Self-referrals 2 46.5 19.1 Total 105 47.6 26.9 11.9%. Education personnel were responsible for only 5.6% of referrals to the diagnostic centre. There were few self-referrals. Data were further analysed to examine the relationship between the age at diagnosis and source of referral (Table 3). Though not statistically significant, the table shows that the means for all categories except one are consistent with the mean of the overall population. The exception is the mean of 63.3 months (over 5 years of age) for the children referred from the educational services. Age at diagnosis The age at diagnosis is defined as the age at which the child was seen for evaluation at the UHWI diagnostic centre. The study assumes that a diagnosis of autistic disorder was made at the time of presentation to the UHWI. The mean age of diagnosis was 47.2 ± 26.7 months or almost four years of age. The minimum and maximum ages of diagnosis were 18 months (1.5 years) and 194 months (16 years), respectively. When extreme values are excluded, the mean age of diagnosis falls to 43.8 ± 17.8 months. Some 95% of children are therefore diagnosed prior to the age of eight years. There was a difference of 0.4 months between the mean age of diagnosis for males and females, but this difference was not statistically significant. The mean age of diagnosis in rural areas was 50.2 months, in suburban areas 45.0 months and in urban areas 40.5 months; these differences were not statistically significant. There was a highly significant difference between the mean ages of diagnosis by socio-economic status (p<0.001). Children of women from professional occupations were diagnosed at a mean age of 31.2 months, those in skilled occupations at 41.8 months and those in unskilled occupations at 70.0 months. Children of unemployed women had their diagnoses made at a mean age of 46.0 months. Diagnostic delay The period between the time when mothers became concerned about their children and the time of diagnosis was defined as the period of diagnostic delay. The mean diagnostic delay was 23.5 ± 15.9 months. There was no statistically significant difference between diagnostic delay and gender or geographical location, but diagnostic delay by socio-economic status was significant at the p<0.001 level. A mean diagnostic delay of 13.5 months was typical for children of professional mothers, while those of mothers in skilled and unskilled professions had diagnostic delays of 22.0 and 46.6 months, respectively. Children of unemployed mothers had a mean diagnostic delay of 25.2 months. The age of concern and the age of diagnosis were positively correlated (p<0.01). Between the time of maternal concern and diagnosis, 23.2% of the children saw one medical professional, 76.8% saw two or more and 33.7 saw three or more. The maximum number of medical professionals seen was five. There was no statistically significant relationship between the number of physicians seen and diagnostic delay.
International Journal of Early Years Education 81 Discussion The male predominance identified among autistic children in Jamaica is consistent with other international studies. However, a predominance of only 4:1 to 5:1 is more typical (American Psychiatric Association 1994; American Academy of Pediatrics 2001b). The higher male predominance identified in Jamaica cannot be explained by this study and requires further investigation. The mean age of maternal concern was found to be 19.1 months in a European study (Giacomo and Fombonne 2002). The mean age of maternal concern in Jamaica was 21.3 months, suggesting little difference in parental concern between Jamaica and the developed world. Professional mothers became concerned at a much earlier age (7 to 8 months) when compared with less educated mothers. This is an expected finding, as educated parents are more likely to be aware of their child s impaired development or behaviour through easier access to information and advice. Jamaican mothers were more concerned about delayed language development or regression of language development than about social impairment or behavioural problems. This is not surprising, given the importance placed on acquiring language milestones in Jamaican culture. The mean age at diagnosis in Jamaica was found to be 43.8 months, exclusive of extreme values. Studies conducted in the United States (Mandell, Novak, and Zubritsky 2005) show a mean age of diagnosis of 37.2 months (3.1 years). The age at diagnosis in the Jamaican population is therefore much later than in developed countries. Studies in other countries have shown that rural children receive a diagnosis of autism 4.8 months later than urban children ((Mandell, Novak, and Zubritsky 2005). This study shows that rural Jamaican children have a similar experience, with a 4.8-month difference in the age of diagnosis between children from urban and rural areas, though this difference was not significant. Although 95% of young Jamaican children receive their health care from primary care medical professionals (Samms-Vaughan 2004), at either health centres or private general practitioners offices, referrals to the diagnostic centre were largely from paediatricians and other specialist services providing care at secondary or tertiary level (76.2%). Primary care health professionals were responsible for only 4.6% of referrals to the diagnostic centre. These findings suggest that the majority of children with autistic disorder are not being identified by primary health care professionals. This may be due to limitation in general practitioners level of awareness of the disorder. Alternatively, the relatively small proportion of direct referrals from general practitioners may be due to referrals being made to paediatricians, rather than directly to the centre. This could be true for just over three-quarters of children, where two or more physicians were seen prior to referral to the diagnostic centre. However, the data also show that a third of children saw three or more medical professionals before diagnosis, suggesting not just a referral to a specialist physician, but multiple physician contacts between the time of parental concern and diagnosis. A high number of physician contacts may be a reflection of parental denial of the existence of a chronic disorder and subsequent doctor shopping. The presence of self-referrals, despite the small numbers, is a positive indication that the general public, if they are knowledgeable of the signs of autism, can play an important role in the early identification of the disorder. The paucity of cases referred by the educational system is of significant concern, particularly as at the mean age of diagnosis of 43 months, the majority of young Jamaican children are in pre-school and the majority of children are diagnosed prior to the age of eight years. This suggests that pre-school and early primary years teachers, like primary health care professionals, may be unaware of the presenting features of autism and that parental concerns about children s development or behaviour are not being discussed with teachers. Alternatively, children with language delays may not be sent to school by their parents. Additionally, similar to primary health care professionals, teachers may be identifying developmental and behavioural concerns
82 M. Samms-Vaughan and L. Franklyn-Banton and recommending parents to medical professionals rather than making direct referrals to the diagnostic centre. The study has shown that although the general population of mothers is becoming concerned about speech delay at an acceptable age, diagnosis is being delayed significantly. The mean delay in diagnosis was 23.5 months, while the mean age of maternal concern was 20.3 months. At this age (20.3 months), autism can be effectively screened for. However, the mean age of diagnosis was 43.8 months. The importance of parents in the early identification of developmental and behavioural disorders of children has been well described (Glascoe, Altemeier and MacLean 1990; Glascoe and Dworkin 1995; Glascoe 1997). Further, the inability of medical professionals to identify developmental and behavioural disorders at routine well-child visits has also been identified (American Academy of Paediatrics, Committee on Children with Disabilities 2001a). As a result, screening tools utilizing parental reports have been developed. The CHAT represents one such tool, specifically designed for the early identification of autism. The use of the CHAT by primary health care professionals would allow early identification of children with autistic disorder. The psychometric properties of the screening tool would also engender confidence in making such a referral directly to the diagnostic centre, rather than through another medical professional, thereby reducing diagnostic delay. Primary health care professionals have their most frequent contact with children in the first 18 months of life, with these contacts determined by immunization schedules. Professionals in the education sector have contact with approximately 10% of Jamaican children who attend day care centres from 6 to 18 months of age, and with 96% of Jamaican children from the ages of three to six years who attend early childhood institutions (Samms-Vaughan 2004). The CHAT was originally designed for administration by health professionals, but education professionals could potentially play an important role in early identification of children with autistic disorder. Because of the time spent with children at early childhood institutions and because of their vast experience of children s typical behaviours, they would be able to accurately report on children s behaviours. Professionals in the education sector could therefore be trained to use appropriate screening tools suited for the ages of children within their institutions. Similar to primary health care professionals, the use of psychometrically sound screening tools would engender confidence in making referrals directly to a diagnostic centre and reduce diagnostic delay. First-contact early childhood professionals, including both primary health care professionals and early childhood practitioners, therefore have tremendous opportunities for intervention to reduce diagnostic delays. With immunization rates at well-child clinics above 90%, there is good access to health centres and, as shown above, good access to early childhood institutions throughout Jamaica for children of all social classes and all geographic locations. However, such professionals need to be adequately trained to recognise the features of this disorder, to utilize screening tools and to be aware of resources for referral. With the increase in prevalence of autism over the last thirty years, and more so in the last decade, many general practitioners and early childhood practitioners may not have received adequate exposure to this condition in their training. In-service training programmes and changes to medical and education training curricula are therefore important early steps to reducing diagnostic delay. This study has also identified some demographic factors influencing the delay in diagnosis, including female gender. Though the cultural expectations in Jamaica are that female children develop at a faster rate than males, the results may be explained by the limited number of females in the study. Diagnosis was made up to 33.1 months earlier for professional mothers than for unskilled mothers and the study showed strong statistical significance between the age of professional diagnosis and the mothers socio-economic status. Low socio-economic status may impact
International Journal of Early Years Education 83 on diagnostic delay in a number of ways, including limited maternal knowledge of developmental milestones and limited resources to access health services. Recommendations As early identification and intervention are important in the outcome of this condition for children, a number of recommendations are being made from this study: (1) General practitioners, early childhood practitioners and paediatricians should listen carefully to parental concerns about children s development. In particular, keen attention should be given to concerns with regards to language development. Parents have been shown by this study to be a reliable source of information about their children s development and behaviour. (2) There should be general public education about child development and red flags for which attention should be sought. In particular, this education should focus on social and behavioural abnormalities. It would be important for these forms of education to be accessible to all parents, but particularly those of low socio-economic status. This can be done in a number of settings, such as antenatal clinics, well-child clinics and Parent Teachers Association meetings at early childhood institutions. (3) Primary health care professionals and educational professionals should be educated about the features of autistic disorder, available screening tools and mechanisms of referral. Limitations This study was limited by a small sample size and incomplete data based on the retrospective nature of the study. References American Academy of Pediatrics, Committee on Children with Disabilities, 2000 2001. 2001a. Developmental surveillance and screening of infants and young children. Pediatrics 108, no. 1: 192 5.. 2001b. The paediatrician s role in the diagnosis and management of autism spectrum disorder in children. Pediatrics, 107, no. 5: 1221 1226. American Psychiatric Association. 1994. Diagnostic and statistical manual of mental disorders, 4th ed. Washington, D C: American Psychiatric Association. Baird, G., A. Charman, and S. Baron-Cohen. 2000. A screening instrument for autism at 18 months of age: A 6-year follow-up study. Journal of American Academy of Childhood and Adolescent Psychiatry 39: 694 701. Baron-Cohen, S. 1992. Can autism be detected at 18 months? The needle, the haystack, and the CHAT. British Journal of Psychiatry 161: 839 43. Baron-Cohen, S., A. Cox, and G. Baird. 1996. Psychological markers in the detection of autism in infancy in a large population. British Journal of Psychiatry 168: 158 63. Blaxill, M.F. 2004. What s going on? The question of time trends in autism. Public Health Reports. 119: 536 51. De Giacomo, A., E. Fombonne. 1998. Parental recognition of development abnormalities in autism. European Child and Adolescent Psychiatry 7: 131. Filipek, P.A., P.J. Accardo, G.T. Baranek, E.H. Jr Cook, G. Dawson, B. Gordon, J.S. Gravel, C.P. Johnson, R.J. Kallan, S.E. Levy, N.J. Minshew, S. Ozonoff, B.M. Prizant, I. Rapin, S.J. Roger, W.L. Stone, S.W. Teplin, R.F. Tuchman, F.R. Volkmar. 1999. The screening and diagnosis of autism spectrum disorders. Journal of Autism and Developmental Disorders 29: 439 84. Filipek P.A., P.J. Accardo, and S. Ashwal. 2000. Practice parameter: Screening and diagnosis of autism. A report of the quality standards subcommittee of the American Academy of Neurology and Child Neurology Society. Neurology 55: 468 79.
84 M. Samms-Vaughan and L. Franklyn-Banton Glascoe, F.P. 1997. Parents concerns about children s development: Prescreening technique or screening test? American Journal of Disease in Children 99: 522 8. Glascoe, F.P., W.A. Altemeier, and W.E. Maclean. 1990. The importance of parents concern about child s development. American Journal of Disease in Children 143: 955 8. Glascoe F.P., and P.H. Dworkin. 1995. The role of parents in the detection of developmental and behavioural problems. Pediatrics 95: 829 36. Howlin, P., and A. Moore. 1997. Diagnosis in autism: A survey of over 1200 patients in the UK. Autism 1, no. 2: 135 62. Mandell, D.S., M.M. Novak, and C.D. Zubritsky. 2005. Factors associated with age of diagnosis among children with autism spectrum disorders. Pediatrics 116, no. 6: 1480 6. Merrick, J., I. Kandel, and M. Morad. 2004. Trends in autism. International Journal of Adolescent Medicine and Health 16: 75 78. Samms-Vaughan, M. 2004. The Jamaica pre-school child: The status of early childhood development in Jamaica. Kingston, Jamaica: The Planning Institute of Jamaica. Scambler D., S. Rogers, and E.A. Wehner. 2001. Checklist for Autism in Toddlers. Journal of the American Academy of Child and Adolescent Psychiatry 40, no. 12: 1457 1463. Wing, L., and D. Potter. 2002. The epidemiology of autistic spectrum disorders: Is the prevalence rising? Mental Retardotion and Development Disabilities Research Review 8: 151 61.