Previous research has found that even after entering specialty care, there is a continued delay in the diagnosis of autism among African-American children compared with white children (Mandell et al., 2002
). The current study extended that research by examining diagnostic patterns after entry into specialty care. The main finding was that African-American children ultimately diagnosed with autism were nearly 3 times more likely than white children to receive another diagnosis first. Among children who received other diagnoses, African-American children were much more likely than white children to receive a diagnosis of conduct or adjustment disorder.
Receipt of diagnoses other than autism, especially ADHD, conduct and adjustment disorders, was common for the entire sample. 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. Children with autism in families that had been Medicaid-eligible for more than 1 year were 3.4 times more likely to first receive some other diagnosis. It is possible that the presentation of autism differs among poorer children, perhaps because of environmental causes or mediators. It is also possible that wealthier families obtained Medicaid eligibility for their children only after confirming the diagnosis. Parent and clinician behavior, which are addressed within the context of ethnicity below, may also be applicable to families of lower socio-economic status.
A number of study limitations should be mentioned, primarily the unknown validity of diagnoses of autism in the Medicaid claims data. While its accuracy has not been specifically examined, Fombonne et al. (2004)
found 97% positive predictive value for chart diagnoses and a research diagnosis of autism. Another important limitation is that there were no measures of symptoms or severity. It is likely that the presence of certain symptoms or the severity of the disorder is closely associated with accurate diagnosis; if, for example, higher functioning children are more likely to be misdiagnosed, it would explain the low prevalence of cognitive disorder diagnoses. There is no reason to suspect, however, that severity differs by race. Third, a number of important variables that may affect interpretation of symptoms and use of services, such as education and family structure, were not available. Similarly, the neighborhoods in which children live may confound the effects of race on diagnosis. Diagnostic services in some neighborhoods may be better than others, and those communities may differ by their racial and ethnic composition. Finally, this study is based on a Medicaid sample in one city and may not generalize to other populations.
Despite these limitations, there are important implications of these findings. Even if we accept the primary limitation that diagnosis of autism was not validated, it still begs the question of why diagnostic patterns differed by race. Possible causes include differences in (1) child presentation; (2) parent behavior in response to symptoms; and (3) clinician responses to child symptoms and parents’ complaints (Mandell & Novak, 2005
Volkmar and Pauls (2003)
suggest conceptualizing autism as a set of behavioral phenotypes; while there is no published evidence regarding differences in presentation by race or ethnicity, their existence may differentially confound diagnosis. Evidence for underlying behavioral phenotypes has been mixed. Some studies have identified distinct clustering of symptoms (Cuccaro et al., 2003
; Tadevosyan-Leyfer et al., 2003
), while others have found one, continuously distributed underlying factor (Constantino et al., 2003
; Spiker, Lotspeich, Dimiceli, Myers, & Risch, 2002
). Cuccaro et al. (2005)
report that African-American children with autism may have more impaired language development than white children, while oral communication with Lord (2005, oral communication) suggested no such differences. In their study of the involvement of GABA receptor subunit genes in autism, Collins et al. (2006)
report invariance across white and a small group of African-American children, but note that different single nucleotide polymorphisms were associated in each ethnic group. Much further research is required to determine whether ethnic genotypic differences exist, and whether they are associated with different clinical presentation.
Some preliminary evidence suggests that cultural factors may affect parents’ recognition and interpretation of symptoms. Daley (2004)
found that Asian Indian parents were more likely to first notice social difficulties rather than speech delays in their children with autism, while studies conducted in the United States have found that parents were more likely to detect general developmental delays or regression in language skills than social or communicative deficits (Coonrod & Stone, 2004
). Daley postulates that these differences are due to the Indian culture, which values social conformity more than the United States. Coonrod and Stone suggest that American parents were less concerned about social milestones than about language development.
The presence of adjustment and conduct disorder diagnoses in the current study suggests the possibilities of ethnic differences in the exchange of information and description of symptoms. Ethnic differences in how parents describe symptoms may lead to an incomplete representation or misattribution of symptoms. The fact that African-American children with autism were more likely than children of other ethnicities to receive a diagnosis of conduct disorder suggests the possibility that African-American parents are more likely than others to describe their children's symptoms in ways that emphasize their children's disruptive behavior. The fact that African-American children and children of other ethnicities—which might include recent immigrants—were more likely than white children to receive a diagnosis of adjustment disorder suggests the possibility that these parents have difficulty communicating symptoms to clinicians in a manner that allows clinicians to translate parental descriptions into diagnostic categories. These speculations clearly require further exploration.
The misdiagnosing of autism may relate to lack of familiarity with the disorder or underutilization of standardized clinical measures. Clinicians may diagnose adjustment disorder when they require more time to evaluate a child. Assigning this diagnosis enables reimbursement and the opportunity for another visit. Conduct disorder may be diagnosed as a function of clinicians’ interpretation of children's disruptive or aggressive behaviors. Clinicians may also be concerned about the effects of labeling children as autistic, and therefore withhold the diagnosis as long as feasible.
The Institute of Medicine (2002)
report, Unequal Treatment
, suggests that the racial differences in diagnostic patterns observed in this and other studies may be attributable to general prejudices held by the clinician, specific stereotypes about health-related behaviors, and the application of rational (if erroneous) decision rules regarding health status. This last type of discrimination, referred to as statistical discrimination (Balsa & McGuire, 2001
), occurs if clinicians have different expectations about the probability of autism occurring in children of different ethnicities. While this issue has not been specifically studied, Balsa, McGuire, & Meredith (2005)
found that physicians had different expectations about the frequency of heart disease and diabetes in white and African-American adults, leading to different rates of diagnosis in the presence of similar symptoms. The authors point out that, alternatively, clinicians’ expectations can lead to disparities in health communication. For example, they found that ethnic disparities in the diagnosis of adults with depression were mediated in large part by clinicians’ failure to elicit or appropriately interpret African-Americans concerns. Similarly, a study of adult primary care practices found that African-Americans were much more likely than whites to say that their physician had not solicited or listened to their complaints and concerns, regardless of the ethnicity of the physician (Cooper-Patrick et al., 1999
). Within this framework, one might hypothesize that the more frequent diagnosis of conduct disorder among African-Americans (but not other ethnic groups) may be associated with clinicians’ erroneous beliefs regarding the increased frequency of conduct disorder among African-American children, while the more frequent diagnosing of adjustment disorder among all groups other than whites may be the result of clinicians’ misinterpretation of parental concerns.
These and other strategies that more closely examine interactions between clinicians, patients and families (Roter et al., 1995
; Wissow, Larson, Anderson, & Hadjisky, 2005
) provide promising models for examining disparities in the diagnosis of children with psychiatric and developmental disorders such as autism. A statistical discrimination model suggests the need to better understand the heuristics clinicians use to make diagnostic decisions, while the miscommunication model suggests the need to more closely observe parent–clinician interactions around diagnosis, and how they differ by ethnicity. The results of this study also suggest the immediate need for further education among specialty practitioners in at least three areas: (1) the symptoms of autism and how they may be differentiated from those of other disorders; (2) greater sensitivity regarding ethnic differences in language used to describe child behavior, and; (3) education and values clarification regarding their own beliefs about the prevalence of autism and its presentation by ethnicity. They also suggest the urgent need to examine whether delivery of care subsequent to diagnosis differ as well.