Relationships Between Ethnicity and Age of Initial ASD Diagnosis in a Clinical Sample

Background: Health care disparities disproportionately impact racial and ethnic minorities (Flores et al., 2008; Lasser et al., 2006; Mensah et al., 2005). Factors such as access to care, provider biases, and poor communication and health literacy have been identified as potential explanations for these differences (US DHHS, 2008). These factors, as well as others (Mandell et al., 2005, 2009), have also been implicated as potential reasons for differences in age of diagnosis in ASDs. Although previous research has indicated that there is no difference in the rates of ASDs in different racial and ethnic backgrounds (Bertrand et al., 2001; Croen et al., 2002), there are reported differences regarding the age at which diagnosis occurs (Mandell et al., 2002).  

Objectives: The current study will examine age of diagnosis and related demographic and behavioral variables in a group of children referred for diagnostic evaluation. 

Methods: 2170 children (1725 males, 445 females) between the ages of 2 and 14 (mean age = 71.81 months, SD = 36.70 months) underwent a comprehensive diagnostic evaluation. The sample was categorized based on caregiver-identified racial/ethnic background: 73.6% (1598) were Caucasian, while 26.4% (572) were from racial or ethnic minority backgrounds (African American, Hispanic, Asian/Pacific Islander, or “Other”). Of the total sample, 829 children (659 males, 170 females; mean age = 62.02 months, SD = 34.61 months) were eventually diagnosed with an ASD; 71.2% (590) were Caucasian and 28.8% (239) were considered racial or ethnic minorities. 

Results: In the group as a whole, the mean age at evaluation for the Caucasian group was 72.85 months (SD = 37.01 months); the mean age at evaluation for the Minority group was 68.91 (SD = 35.67 months; t(2168) = 2.21, p = .027). The groups did not differ in terms of caregiver-reported problem behaviors (CBCL internalizing problems: t(2077) = -1.12, p > .05; externalizing problems: t(2077) = 1.71, p > .05; total problems: t(2077) = 0.50, p > .05). Within the ASD group, the mean age at evaluation for the Caucasian group was 63.95 months (SD = 36.21 months); the mean age at time of evaluation for the Minority group was 57.26 months (SD = 29.86 months; t(827) = 2.53, p = .01). Caregivers reported that children in the Minority group were exhibiting more internalizing behavior problems (t(788) = -3.07, p = .002) and more total problems (t(788) = -2.08, p = .038) than children in the Caucasian group.   

Conclusions: These results indicate that in our sample there is a difference in average age at time of evaluation depending on minority status. However, the pattern is not consistent with previous findings suggesting that children from a racial/ethnic minority background are diagnosed at later ages than Caucasian children. Additional factors, such as developmental level, more specific demographic information, severity of impairment, and caregiver reported behavioral profiles will be further explored in order to better understanding the patterns of similarities and differences between children in these two groups. Clinical implications, future directions, and potential limitations, including referral source, will also be discussed.