Combining ASD-Specific Screening Tools to Capture Red Flags in 12 Month Old High-Risk Siblings

Background:

The American Academy of Pediatrics recommends screening toddlers for ASD at 18 & 24 months. Closely monitoring children at higher risk (e.g. having a sibling with ASD) is especially critical (CDC, 2014) as approximately 20% of younger siblings are at an increased risk for developing ASD (Ozonoff, 2011), therefore requiring intensified developmental surveillance. By using a combination of screening tools as early as 12 months in a high-risk population with consideration for home and clinic settings, providers may identify subtle delays and ASD specific red flags at an earlier age. According to DSM-5 criteria, persistent deficits in social communication and social interaction occur across multiple contexts. Employing multi-source screening at 12 months may provide comprehensive yet efficient means to initiate earlier ASD intervention for infants deemed high-risk.

Objectives:

To examine how combination of clinical assessment, home observation, parent report and ASD-specific screening can be used in a complementary fashion to detect red flags starting as early as 12 months, ultimately testing a downward extension of current AAP guidelines in a high-risk sample.

Methods:

High-risk 12-month olds were assessed as part of a federally-funded longitudinal study examining siblings. Assessment batteries included 4 samples of early social behavior with consideration for multiple settings: a communication assessment, a video-recorded home observation, parent report measure, and an ASD-specific screening tool. The CSBS (Wetherby & Prizant, 2001) was used to assess communication development, the Systematic Observation of Red Flags of ASD (SORF; Wetherby & Woods, 2004), an ASD-specific screening tool, was used to rate symptomatology within CSBS and home observations. The Early Screening for Autism and Communication Disorders (ESAC; Wetherby, Woods & Lord, 2012), parent questionnaire, was used to collect information on early social communication and presence of repetitive behaviors. Using previous research collected from ESAC and SORF in 18-24 month-olds, cut-offs were determined, where a positive screen for 12-month siblings on at least 2 of 4 measures led to eligibility for an experimental intervention. Within our study, 17 (20 projected by May 2016) high-risk infants were deemed eligible for intervention based on positive screening utilizing these four measures. Comparisons between measures used to assess qualification for intervention were analyzed using the Chi-Squared test and Wilcoxon Two-Sample test.  

Results:

Measures conducted in the clinic by highly trained clinicians were more likely to positively identify early ASD signs than the measure conducted in the home or parental report at the 5% significance level (p<.005). Of 17 infants who qualified for the intervention study 76% (n=12) qualified based on the CSBS and 100% (n=17) qualified based on the clinic SORF compared to 41% based on the ESAC (n=7) and 50% on the home SORF (n=8).

Conclusions:  

Findings suggest that while the CSBS is examining communication, its structured tasks involving object temptations may reveal subtle social delays in high-risk 12-month olds to a trained clinician. Applying an ASD-screening tool to rate the communication sample of the CSBS, closely examining social behaviors and emerging repetitive behaviors, may expose earlier symptomatology and provide more quantitative assessment of red flags.