Factors Associated With Age of Diagnosis Among Children With Autism Spectrum Disorders

Abstract

Objective-Early diagnosis of children with autism spectrum disorders (ASD) is critical but often delayed until school age. Few studies have identified factors that may delay diagnosis. This study attempted to identify these factors among a community sample of children with ASD.Methods-Survey data were collected in Pennsylvania from 969 caregivers of children who had ASD and were younger than 21 years regarding their service experiences. Linear regression was used to identify clinical and demographic characteristics associated with age of diagnosis.Results-The average age of diagnosis was 3.1 years for children with autistic disorder, 3.9 years for pervasive developmental disorder not otherwise specified, and 7.2 years for Asperger's disorder. The average age of diagnosis increased 0.2 years for each year of age. Rural children received a diagnosis 0.4 years later than urban children. Near-poor children received a diagnosis 0.9 years later than those with incomes >100% above the poverty level. Children with severe language deficits received a diagnosis an average of 1.2 years earlier than other children. Hand flapping, toe walking, and sustained odd play were associated with a decrease in the age of diagnosis, whereas oversensitivity to pain and hearing impairment were associated with an increase. Children who had 4 or more primary care physicians before diagnosis received a diagnosis 0.5 years later than other children, whereas those whose pediatricians referred them to a specialist received a diagnosis 0.3 years sooner.Conclusion-These findings suggest improvements over time in decreasing the age at which children with ASD, especially higher functioning children, receive a diagnosis. They also suggest a lack of resources in rural areas and for near-poor families and the importance of continuous pediatric care and specialty referrals. That only certain ASD-related behaviors, some of which are not required to satisfy diagnostic criteria, decreased the age of diagnosis suggests the importance of continued physician education.Early diagnosis of autism spectrum disorders (ASD) is critical for a number of reasons, 1, 2 perhaps most important because interventions to improve the functioning of children with ASD may be more effective with younger children.3 -6 Evidence suggests that early treatment optimizes long-term prognosis, 7 and treatment yields diminishing returns as children get older. 8 Several studies have estimated that the gains in functioning associated with early treatment will result in considerable cost savings to both families of children with ASD and the systems in which they are served. [9][10][11]

Disparities in Diagnoses Received Prior to a Diagnosis of Autism Spectrum Disorder

“…It is possible that the sample represents a particularly diagnostically complex group of children, which would explain both their late diagnosis relative to other children (Mandell et al, 2005a) and the high proportion of children who received diagnoses other than autism. The role of economic disadvantage should not be discounted, however.…”

“…Despite increasing evidence that autism can be accurately identified in very young children (Baird et al, 2001;Bryson, Rogers, & Fombonne, 2003;Charman et al, 2005;Lord et al, 2006), diagnosis is often delayed until children are of school age (Howlin & Moore, 1997;Mandell, Listerud, Levy, & Pinto-Martin, 2002;Mandell, Novak, & Zubritsky, 2005a). This delay may be due to inadequate screening practices (Dearlove & Kearney, 1990;Dobos, Dworkin, & Bernstein, 1994;Sices, Feudtner, McLaughlin, Drotar, & Williams, 2003), pediatricians' slow response to parental concerns (Glascoe, 1997;Shevell, Majnemer, Rosenbaum, & Abrahamowicz, 2001), the low sensitivity of screening instruments for autism (Dumont-Mathieu & Fein, 2005), and a general lack of awareness of symptoms (Shah, 2001).…”

Identification and Evaluation of Children With Autism Spectrum Disorders

“…This reflects the phenomenon of "diagnostic substitution," whereby the number of children receiving special education under other categories (primarily MR, speech impairment, and learning disabilities) has decreased over the same time period. In addition, some increase in prevalence may be attributable to inaccuracies in diagnosis for a number of reasons, including labeling biases when schools used less rigorous criteria than those needed for a DSM diagnosis, [44][45][46][47][48] when educational funding trends influenced diagnosis, 49 and/or when parents of children with marginal criteria advocated for the AD label to qualify for supplementary services (eg, year-round schooling) described in the IDEA amendments. 50,51 The impact of these factors on current prevalence estimates has been controversial and illustrates the reason why educational administrative data reported in some studies that receive media attention should not be considered for epidemiologic studies.…”

Parenting Interventions for Children with Autism Spectrum and Disruptive Behavior Disorders: Opportunities for Cross-Fertilization

“…Based on the diagnostic criteria for DBDs versus ASDs, children with DBD may be diagnosed later than children with ASD. Early identification of autism in children under age 3 is becoming increasingly common (Charman and Baird, 2002;Filipek et al, 1999Filipek et al, , 2000Mandell et al, 2005b).…”