International Meeting for Autism Research: Predictive Value of Red Flags for Communication at 6 and at 12 Months for M-CHAT Results at 18 Months In Children with Autism Spectrum Disorders

Predictive Value of Red Flags for Communication at 6 and at 12 Months for M-CHAT Results at 18 Months In Children with Autism Spectrum Disorders

Thursday, May 12, 2011
Elizabeth Ballroom E-F and Lirenta Foyer Level 2 (Manchester Grand Hyatt)
3:00 PM
R. Maxim, MD1, E. Judd2, L. Eversmeyer2, D. Swann2, P. Deutsch2, C. Guild3, N. Tamirisa2, M. W. Baig2, S. Stewart4, A. Nay4, T. Maxim2, H. Klein2 and E. S. Armbrecht3, (1)Saint Louis University, Clayton, MO, (2)SSM Cardinal Glennon Children's Hospital, St.Louis, MO, (3)Center for Outcomes Research and Department of Pediatrics., Saint Louis University, St.Louis, MO, (4)Saint Louis University, St.Louis, MO
Background:  Early identification of autism spectrum disorders (ASD) is associated with improved outcomes.  Few studies have examined the predictive utility of an autism screening tool at 6 and 12 months, especially in community-based populations.

Objectives:  To assess the ability of Red Flags for Communication (RFC), a new autism screening tool administered at 6 and 12 months, to predict M-CHAT results (i.e., pass or fail) at 18 months.

Methods:  Educators from 26 Parents as Teachers Programs, a community-based, in-home parent support service sponsored by public school districts, screened more than 3,000 children ages 5 to 27 months for indicators of autism and other developmental delays. These children were assessed every 6 months using the Ireton Child Development Chart (ICDC); RFC was used for children ages 6 and 12 months; M-CHAT was used for children ages 18 and 24 months.  Using our database of screening tool responses, we determined patterns of passing and failing 3 consecutive observations using RFC and M-CHAT to estimate the association between RFC results (at 6 and 12 months) and M-CHAT at 18 months.  We employed the Fisher exact test to assess statistically significant differences in passing or failing M-CHAT between two groups: (1) consecutive passing RFC at 6 and 12 months vs. (2) consecutive failing RFC at 6 and 12.  With the same statistical method, we also examined the association between RFC results at 6 months alone and M-CHAT results.

Results:  Of the 260 subjects with complete screening data at 6, 12 and 18 months, 8 (or 3.1%) failed RFC at 6 and 12 months.  Three of these consecutive RFC failing subjects (or 37.5%) also failed M-CHAT (at 18 months).  Two of the three subjects with this screening result pattern were diagnosed with autism; the diagnosis of the other one is unknown (i.e., loss to follow-up).  By comparison, 3 of 252 subjects or (1.2%) with consecutive RFC passing also failed M-CHAT (p = 0.0004).  There were 324 subjects with complete screening data at 6 and 18 months.  Among these subjects, 3 of 13 (or 23.1%) who failed RFC (at 6 months) also failed M-CHAT; while 5 of 311 (or 1.6%) who passed RFC (at 6 months) failed M-CHAT (p = 0.0025).

Conclusions:  A child who fails the RFC at 6 months has a 14.1 times higher risk than a community-based population to fail the M-CHAT at 18 months.  The risk for failing the MCHAT at 18 months further increases if the child fails consecutive RFC at both 6 and 12 months.  By contrast, children who passed the RFC at 6 and 12 months had a high probability (96.7%) of passing the M-CHAT at 18 months.  Use of the RFC screening tool at 6 months of age may improve the early identification of autism spectrum disorders in children.

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