1. Charman T, Pickles A, Chandler S, Wing L, Bryson S, Simonoff E, Loucas T, Baird G. {{Commentary: Effects of diagnostic thresholds and research vs service and administrative diagnosis on autism prevalence}}. Int J Epidemiol;2009 (Sep 7)
2. Giuliodori K, Ganzetti G, Campanati A, Simonetti O, Marconi B, Offidani A. {{A non-responsive chronic autoimmune urticaria in a 12-year-old autistic girl treated with cyclosporin}}.{ J Eur Acad Dermatol Venereol};2009 (May);23(5):619-620.
3. Hertz-Picciotto I. Commentary: {{Diagnostic change and the increased prevalence of autism}}. {Int J Epidemiol};2009 (Sep 7)
4. King M, Bearman P. {Diagnostic change and the increased prevalence of autism}. {Int J Epidemiol};2009 (Sep 7)
BACKGROUND: Increased autism prevalence rates have generated considerable concern. However, the contribution of changes in diagnostic practices to increased prevalence rates has not been thoroughly examined. Debates over the role of diagnostic substitution also continue. California has been an important test case in these controversies. The objective of this study was to determine the extent to which the increased prevalence of autism in California has been driven by changes in diagnostic practices, diagnostic substitution and diagnostic accretion. METHODS: Retrospective case record examination of 7003 patients born before 1987 with autism who were enrolled with the California Department of Developmental Services between 1992 and 2005 was carried out. Of principal interest were 631 patients with a sole diagnosis of mental retardation (MR) who subsequently acquired a diagnosis of autism. The outcome of interest was the probability of acquiring a diagnosis of autism as a result of changes in diagnostic practices was calculated. The probability of diagnostic change is then used to model the proportion of the autism caseload arising from changing diagnostic practices. RESULTS: The odds of a patient acquiring an autism diagnosis were elevated in periods in which the practices for diagnosing autism changed. The odds of change in years in which diagnostic practices changed were 1.68 [95% confidence interval (CI) 1.11-2.54], 1.55 (95% CI 1.03-2.34), 1.58 (95% CI 1.05-2.39), 1.82 (95% CI 1.23-2.7) and 1.61 (95% CI 1.09-2.39). Using the probability of change between 1992 and 2005 to generalize to the population with autism, it is estimated that 26.4% (95% CI 16.25-36.48) of the increased autism caseload in California is uniquely associated with diagnostic change through a single pathway-individuals previously diagnosed with MR. CONCLUSION: Changes in practices for diagnosing autism have had a substantial effect on autism caseloads, accounting for one-quarter of the observed increase in prevalence in California between 1992 and 2005.
5. Nassar N, Dixon G, Bourke J, Bower C, Glasson E, de Klerk N, Leonard H. {{Autism spectrum disorders in young children: effect of changes in diagnostic practices}}. {Int J Epidemiol};2009 (Sep 7)
BACKGROUND: It is unclear whether the increase in autism over the past two decades is a real increase or due to changes in diagnosis and ascertainment of autism spectrum disorders (ASDs), which include autism, Asperger syndrome and pervasive developmental disorder not otherwise specified (PDD-NOS). The aim of this study was to examine the trends in ASD over time in Western Australia (WA) and the possible effects and contribution of changes in diagnostic criteria, age at diagnosis, eligibility for service provision based on ASD diagnoses and changes in diagnostic practices. METHODS: A population-based study was conducted among the cohort of children born in WA between 1983 and 1999 and diagnosed with ASD between the age of 2 and 8 years up to December 31, 2004. The trend in ASD diagnosis over the study period was assessed by investigating birth cohort and period effects, and examining whether these were modified by age of diagnosis. ASD diagnosis corresponding with changes in diagnostic criteria, funding and service provision over time were also investigated. A subgroup analysis of children aged </=5 years was also conducted to examine trends in the incidence and age of diagnosis of ASD and intellectual disability (ID) and to investigate the role of changes in diagnostic practices. RESULTS: The overall prevalence of ASD among children born between 1983 and 1999 and diagnosed by age 8 was 30 per 10 000 births with the prevalence of autism comprising 21 per 10 000 births. The prevalence of ASD increased by 11.9% per annum, from 8 cases per 10 000 births in 1983 to 46 cases per 10 000 births in 1999. The annual incidence of ASD, based on newly diagnosed ASD cases in each year from 1985 to 2002, increased over the study period. The increase in incidence of ASD appeared to coincide with changes in diagnostic criteria and availability of funding and services in WA, particularly for children aged <5 years. The age-specific rates of autism and PDD-NOS increased over time and the median age of diagnosis for autism decreased from 4 to 3 years of age throughout the 1990s. For children aged </=5 years the incidence of ASD diagnosis increased significantly from 1992, with an average annual increase of 22%. Similar findings were found for autism. In the corresponding years the incidence of diagnosis of severe ID fell by 10% per annum and mild-moderate ID increased by 3% per annum. CONCLUSIONS: The rise in incidence of all types of ASDs by year of diagnosis appears to be related to changes in diagnostic and service provision practices in WA. In children aged </=5 years, diagnosis of severe ID decreased, but mild-moderate ID increased during the study period. A true increase in ASD cannot be ruled out.
6. Rutter M. {{Commentary: Fact and artefact in the secular increase in the rate of autism}}. {Int J Epidemiol};2009 (Sep 7)
