Background:

The screening test that is most commonly recommended and used for autism screening in pediatric practice is the M-CHAT (Modified-Checklist for Autism in Toddlers) Robins, D., Fein, D., Barton, M., & Green, J. (2001). While this parent questionnaire has the best psychometric properties compared to alternatives, it still produces a substantial over-referral rate. However, use of a validated structured follow-up interview (M-CHAT F/U) has been shown to lower this over-referral rate by 90% of cases (Kleinman,et al, 2007) allowing the parent to be reassured and a false positive referral avoided. Unfortunately the M-CHAT f/u procedure can be a lengthy procedure and, when used is typically reserved for another encounter by a different professional which leaves parents in an unnecessary state of worry and is an expense.

Comparing the predictive validity of standard MCHAT with CHADIS-based MCHAT follow-up with and without pediatric observations and overall impressions (PAFOS):

We have administration to develop an efficient procedure to make the MCHAT F/U more feasible to administer at the time of the typical well child visit in which a positive MCHAT is uncovered. This was possible because we could take advantage of the known pattern of responses by CHADIS computer to prompt the doctor to ask just the right questions and to have the computer rescore the test after every clinician entry of parent response so the process does not have to continue any longer than necessary. Our network of pediatricians in Maryland are involved in this project and have recently been motivated by both the prospect of getting their American Board of Pediatrics recertification requirements accomplished for themselves and free (with subject fees) autism evaluations for the children screening positive on the MCHAT. We plan to screen 4,500 children, aiming for 30 true positive cases and about 450 total MCHAT positive screens. The standard MCHAT results will be compared with the CHADIS MCHAT Follow-Up results to determine how well each predicts a more detailed diagnostic assessment done at the Kennedy Krieger Institute (KKI) Center for Autism and Related Disorders (CARD). 300 parents of children with positive MCHAT screens who also had a pediatrician complete the CHADIS MCHAT Follow-Up with the PAFOS observation scale at ages 18-36 months will be recruited for further evaluation at KKI. The parent will repeat the MCHAT and CHADIS-MCHAT-Follow-Up in a second session (in person or by phone) with a blinded research assistant. All children failing the standard MCHAT screen at the pediatric visit will be assessed diagnostically for presence of an ASD diagnosis, regardless of their initial or repeat CHADIS-MCHAT–Follow-Up results. The diagnostic assessment at KKI will utilize the standardized ADOS assessment tool, the Mullen Developmental Assessment and the McArthur-Bates Communicative Development Inventories administered by a trained KKI clinical staff member.

Funding:

NIMH SBIR award (2)