International Meeting for Autism Research: Identification of Asperger Disorder (AD): a Pilot Study in Gipuzkoa, Spain

Identification of Asperger Disorder (AD): a Pilot Study in Gipuzkoa, Spain

Saturday, May 22, 2010
Franklin Hall B Level 4 (Philadelphia Marriott Downtown)
11:00 AM
J. Fuentes , Child & Adolescent Psychiatry Unit, Policlinica Gipuzkoa and GAUTENA, San Sebastian, Spain
A. Altxu , APNABI, Bilbao, Spain
N. Tamayo , Child & Adolescent Psychiatry Unit, Policlinica Gipuzkoa, San Sebastian, Spain
A. Porcel , Child & Adolescent Psychiatry Unit, Policlinica Gipuzkoa, San Sebastian, Spain
I. Isasa , Child & Adolescent Psychiatry Unit, Policlinica Gipuzkoa, San Sebastian, Spain
I. Gallano , Clinical Team, GAUTENA, San Sebastian, Spain
R. Canal , School of Education, University of Salamanca, Salamanca, Spain
M. Posada , Rare Diseases Research Institute, Carlos III Health Institute, Madrid, Spain
Background:
Two ways of enhancing appropriate identification of Asperger Disorder (AD) include broad screening of target populations with specific tests, and routine surveillance by pediatricians.

Objectives:
To assess the efficacy of the CAST (Childhood Asperger Screening Test) as a screening instrument among 4 and 6-year-old children in Gipuzkoa, a county of 680.000 inhabitants in the Basque Country of Spain. The region is known for GAUTENA, a 31 year-old comprehensive community program for autism-spectrum disorders (ASD), which provides an appropriate setting for whole-population studies
Methods:
The CAST was translated into Spanish and Basque, adapted to cultural factors, and reverse translated to ensure accuracy. All public pediatric clinics in the county participated in the study (N=33). Parents were invited to complete the CAST during routine visits between June 2007 and May 2008. The responses were classified, following published criteria, into “HIGH likelihood” of AD (score of 15 or more); “MEDIUM likelihood” (12-14 points), and “LOW likelihood” (11 or less).

The HIGH cases were re-interviewed by phone, using a novel CAST decision-tree manual. Cases still classified as HIGH after phone screening were clinically assessed with the ADI-R, ADOS-G and Vineland Scale. To identify possible false negatives, the Social Communication Questionnaire (SCQ) was sent to all HIGH and MEDIUM cases, and to a 10% random selection of LOW cases.

Case identification was compared to all cases with birthdays falling within the same age period who had already been referred to GAUTENA, and to files in the Special Education Registry and the Psychiatric Registry of the Basque Health System.
Results:
The mean response rate across clinics was 18% (range 1-77%), yielding 2,012 screened children (13.0% of the eligible population). There were 18 children in the HIGH likelihood score (0,89% of the sample); 48 (2.3%) cases in the MEDIUM range, and 1,925 (95.6%) in the LOW range. The subsequent phone interview of HIGH cases allowed elimination of 77% of them, reducing the need for further work up. Three children not previously identified in GAUTENA met criteria for AD following the CAST and clinical assessment (one case was CAST-false negative, but entered assessment because of concern of his pediatrician). The SCQ did not identify any false negatives among the eliminated HIGH (N=18), the MEDIUM (N=48), and the random sample of LOW cases (N=192).


Conclusions:

A prevalence of 1 in 670 in a sample of 2,012 children ages 4 and 6 was found in Gipuzkoa, Spain. This rate falls within the range described for Finland (1 in 400) and Canada (1 in 1,000). The CAST can be incorporated into routine pediatric practice and may help enhance timely identification of AD cases. Training of pediatricians will be needed to ensure accuracy, and subsequent phone review of those scoring above cut-point will simplify clinical practice and reduce unnecessary costs.

See more of: Epidemiology
See more of: Clinical & Genetic Studies