What Happens after Early Autism Screening? Factors That Predict Evaluation Attendance

Background: Autism spectrum disorder (ASD) can be detected in toddlers prior to 24 months (Baranek et al., 2009, Pierce et al., 2011), which helps families access early intervention. However, age of diagnosis and participation in follow-up can differ by screening age, sex, race, ethnicity, and maternal education (Dietz et al., 2007, Giarelli et al., 2010, Khowaja et al., 2015, Mandell et al., 2009).

Objectives: This study examines evaluation attendance by parents of toddlers who screened at-risk for ASD at 12, 15, or 18 months, and analyzes the relation between evaluation attendance and demographic factors.

Methods: The sample included 710 (M_age=15.95 mos, SD=2.76) toddlers who screened at-risk for ASD at well-child visits. Children were screened at 12 months (Infant Toddler Checklist (ITC) and First Year Inventory-Lite (FYI-L)); 15 months (FYI-L and Modified Checklist for Autism in Toddlers, Revised, with Follow-Up (M-CHAT-R/F)); or 18 months (M-CHAT-R/F). Pediatrician ASD concerns also denoted risk at each age. Parent-reported demographics included the child’s sex, race, ethnicity, and mother’s education. Families of at-risk children were invited for a free evaluation that resulted in a diagnosis of ASD, other developmental disorders (DD) or no diagnosis (ND).

Results: There was a significant difference in evaluation attendance between age groups: 30.9% attended at 12 months, 19.1% attended at 15 months, and 35.3% attended at 18 months, χ²(2, N=710)=17.20, p<.001. Evaluation attendance did not differ between males (30.2%) and females (28.7%), p=.378, or between low (28.9%) and high (29.8%) maternal education groups, p=.438. However, significantly more minority race families (34.9%) attended evaluations compared to White families (27.4%, χ²(1, N=597)=3.89, p=.030), and significantly fewer Hispanic/Latino families (25.2%) attended compared to non-Hispanic/Latino families (35%, χ²(1, N=518)=4.82, p=.017). Across age groups, 203 children completed an evaluation (N_ASD=51, N_DD=90, N_ND=62). There were significant differences in diagnoses across age groups, χ²(4, N=203)=36.93, p<.001. At 12 months, 23.7% were ASD, 32.2% were DD, and 44.1% received ND. At 15 months, 4.3% were ASD, 43.5% were DD, and 52.2% received ND. At 18 months, 35.7% were ASD, 52% were DD, and 12.2% received ND.

Conclusions: Overall, attendance was lower than expected, although not inconsistent with research examining screening prior to 18 months (Dietz et al., 2007). Race and ethnicity related to evaluation attendance. Lower income and minority families often experience barriers to care (Liptak et al., 2008), and thus may have a greater need for accessible resources, making them more likely to attend a free evaluation. Hispanic/Latino families may be less likely to attend due to concern for language barriers (Zuckerman et al., 2009). Attendance seemed most impacted by screening age, with parents less likely to attend at 15 months compared to 12 or 18 months. Parents and pediatricians may have had less confidence in 15 month screen positive results, leading to lower attendance rates. Differential rates of diagnosis by age suggest lower accuracy in screening at 15 months: only 4.3% of at-risk 15-month-olds met criteria for ASD and a majority had no diagnosis. Future research may be able to refine screening thresholds at 15 months.