Aggressive and self-injurious behaviors, often present in children with ASD (Holden and Gitlesen 2006; McCracken et al. 2004; Volkmar et al. 2004), may increase the risk of hospitalization, as may a lack of appropriate community services. Clinicians often are unfamiliar with relevant interventions (Heidgerken et al. 2005), there often are long waiting lists for treatment programs (Levy et al. 2003), and education services, which comprise the bulk of interventions delivered to children with ASD, vary in quality and intensity (Lord et al. 2005; Stahmer 2006). In addition, private insurance companies often exclude autism as a covered diagnosis or limit coverage of related services (Birenbaum et al. 1990; Krauss et al. 2003), which may ultimately lead to the need for more intensive and restrictive care. Given this latter set of factors and the fact that few localities have decision rules governing care for children with ASD (Stahmer and Mandell 2006), risk for hospitalization may vary depending on the resources families bring to bear on the process of negotiating for services (Mandell et al. 2005).

There was no difference between the groups regarding the age at which caregivers first expressed concerns to a clinician; however, hospitalized youth received an ASD diagnosis an average of 1.6 years later than non-hospitalized youth. Hospitalized youth were more likely to use psychotropic medications and less likely to have used early intervention services.

Table 2 provides the result of the Cox regression predicting first hospitalization. Each year of age was associated with a decrease in hospitalization risk (odds ratio [OR] = 0.81), which should be interpreted as a decrease in the risk for hospitalization over time, rather than a decrease in risk associated with older age. Youth living in single parent homes were more likely to be hospitalized (OR = 2.54), as were youth who were diagnosed at a later age (OR = 1.10). Youths diagnosed with PDD-NOS had less than half the odds (OR = 0.46) of being hospitalized relative to youth with autistic disorder. Engaging in self-injurious behavior (OR = 2.14), aggressive behavior (OR = 4.83), being diagnosed with depression (OR = 2.48) or obsessive compulsive disorder (OR = 2.35), or taking psychotropic medications (OR = 2.08) all increased the odds of hospitalization.

Children of single parents were at increased risk for hospitalization, perhaps because these families have fewer resources to obtain appropriate services for their children. For these families, attending appointments or implementing home-based activities may come at the sacrifice of a day’s pay. Alternatively, hospitalization may act as respite for highly distressed families (Dossetor et al. 1993). In general, the demographic characteristics of the hospitalized children and the fact that they were less likely to receive early intervention paint a picture of the traditionally underserved families with fewer resources. The fact that being a single parent remained significant in the adjusted model, while other socio-demographic characteristics did not suggests the particular burden associated with this family arrangement and provides evidence for the idea of hospitalization as respite for families when other supports are not available.

An alarming finding is that the risk of hospitalization increased over time. Despite considerable efforts over the past 20 years to reduce the use of psychiatric hospitalization because of the associated costs and the value of keeping children in their communities (Center for Mental Health Services 1999; Knitzer and Olson 1982), some groups of children may be increasingly hospitalized. For example, while Harpaz-Rotem et al. found that while the percentage of privately insured children who were psychiatrically hospitalized dropped from 0.36% in 1995 to 0.23% in 2000, the percentage of children with some diagnoses who were hospitalized went up (Harpaz-Rotem et al. 2005). Changing diagnostic practices could account for these differences. It also could be that as an increasing number of children are diagnosed with ASD, the communities in which they are served are unprepared to meet their needs (Mandell and Palmer 2005). A backlog in the availability of community-based services may result in more children being hospitalized.

A number of study limitations should be considered. Perhaps primary among them is the validity of ASD diagnoses and reporting of related symptoms. All respondents indicated that the diagnosis was made by a physician or psychologist. Studies have found good to excellent reliability associated with the diagnosis of ASD by healthcare professionals (Fombonne et al. 2004; Hill et al. 2001; Mahoney et al. 1998). A related limitation is that data were collected only on some symptoms associated with ASD. Our goal was to focus on those symptoms that might differentiate subtypes of children with ASD. In the process, we may have missed symptoms that are associated with hospitalization such as specific stereotypies, socialization or communication deficits. A third limitation is the potential bias in survey respondents, especially given the sampling method. Despite the similarities between the experiences and ethnicity of survey respondents and children with ASD in Pennsylvania described in the methods section, families motivated to complete this survey may have characteristics and experiences different from those of non-responders. A fourth limitation is that caregivers were asked to recall events that may have happened much earlier. Differential recall about, for example, age of diagnosis or age of hospitalization may have biased the results. Finally, we did not collect information on repeat hospitalizations, duration of hospital stays, placement in residential facilities, which means that our outcome of interest can only be treated as dichotomous. In addition, we collected no information on insurance, which may greatly affect the risk of hospitalization.

Despite these limitations, there are important implications related to these findings. The results suggest some potential points for intervention to reduce psychiatric hospitalization among children with ASD. For example, especially for younger children, behavioral interventions may reduce the aggressive and self-injurious behaviors that lead to hospitalization (Bodfish, 2004; Volkmar et al. 1999). Pharmacological treatments also have been developed to address these behaviors (Hollander et al. 2003), but there are many concerns about long-term consequences, especially in young children (Volkmar 2001).

There is a particular need for crisis intervention strategies that divert children with ASD from hospitalization, similar to those that have been developed for children with other psychiatric disorders (Henggeler et al. 2003). These regular (Jacobson and Mulick 2000) and crisis (Sheidow et al. 2004) interventions are expensive and many communities have little infrastructure to deliver them at the required intensity (Heidgerken et al. 2005; Stahmer 2006; Stahmer and Mandell 2006). Increased investment in these services, however, has the potential to significantly reduce the need for more costly inpatient services.

The profile of hospitalized children and their families suggests the need for careful discharge planning that includes a thorough family—as well as child—assessment to determine the root causes. Interventions limited to addressing children’s clinical needs may not be as effective as those that address family needs as well. Families with fewer resources, especially single-parent families, require respite care, which reduces caregiver stress and improve family functioning (Botuck and Winsberg 1991; Cowen and Reed 2002). Respite care often is in short supply (McConkey and Adams 2000), however, and ironically, aggressive and self-injurious behaviors often disqualify children from its use (McGill et al. 2006).

The finding that earlier diagnosis was associated with decreased hospitalization risk, combined with the bivariate finding that hospitalized children were less likely to use early intervention services, raises the possibility that early treatment may decrease the need for later, more costly services. The association of hospitalization and age of diagnosis bordered on marginal significance, and therefore bears replication before deriving too many implications from it; however; an increasing number of studies suggest that earlier intervention results in better outcomes (Lord and McGee 2001) and that gains in functioning associated with early treatment will result in cost savings to the family and the systems in which children with ASD are served (Jacobson and Mulick 2000; Jacobson et al. 1998; Jarbrink and Knapp 2001).