P0076 - "I'm Worried About My Child": A Longitudinal Investigation of Parental Concerns and Repeat Screening in Toddlers with Familial Risk of Autism Spectrum Disorder

Background: Autism spectrum disorder (ASD) is characterized by differences in communication, social interaction, and restricted and repetitive behaviors. While 85% of parents report developmental concerns well before 36 months, the median age of first diagnosis is 51 months (CDC, 2020). Toddlers with an older sibling with ASD are at heightened risk (HR) of receiving an ASD diagnosis (18.7% recurrence rate; Ozonoff et al 2011). Early identification of ASD is critical for early intervention, which improves later outcomes.

The AAP recommends universal ASD screening at 18 and 24 months but screening often does not occur at both ages. The Modified Checklist for Autism in Toddlers, Revised with Follow-Up (M-CHAT-R/F; Robins et al., 2014) is a validated screener that is reliable and widely used in pediatric practices for early identification. It has good sensitivity but poor PPV. In children screened twice, 24-month re-screening was marginally more sensitive and had higher PPV than 18-month screening and screen-positive rates were higher at 18 months than at 24 months (Guthrie et al. 2019).
This study examines parental concerns in combination with M-CHAT data from HR toddlers to explore the importance of re-screening at 24 months.

Methods: The data includes pass/fail scores from M-CHAT or M-CHAT-R/F at 18 and 24 months, parent concerns, and diagnostic classification at 36 months (No Diagnosis, Language Delay, ASD) from 84 HR toddlers. Parents were asked if they had concerns about their child each month from 15-36 months, and answers were collapsed into yes/no for parent concerns at 15-17, 19-23, and 25-36 months.
Language delay (LD, N=33) was determined by scores on standardized language measures. ASD diagnosis (N=11) was determined by the Autism Diagnostic Observation Schedule and clinical judgment. No Diagnosis toddlers (ND, N=40) had neither an ASD diagnosis nor language delay.

Results: In the ASD group, 4 children (36.3%) failed both the 18 and 24 month M-CHAT, 1 (9.1%) failed at 18 but passed at 24 months, and 6 children (54.5%) passed at both 18 and 24 months. While 4 LD children (12%) failed the M-CHAT at 18 months, none failed at 24 months.
Notably, at 15-17 months, 63.6% of parents of children with ASD reported concerns, compared to 36.4% of LD and 30% of ND groups. Of children with ASD who passed the M-CHAT at both 18 and 24 months, 66.6% had parental concerns reported at least once.


Conclusion: Re-screening for ASD at 24 months is often missed, but data suggest that sensitivity and PPV can be improved with repeated screening. These results emphasize the importance of universal re-screening at 24 months. Furthermore, consideration of early parental concerns at well-child visits in conjunction with screening may help distinguish children who may otherwise miss access to early intervention opportunities.