There is not enough information about the feasibility and validity of the M-CHAT (Robins et al., 2001) in a population-based study or the feasibility of any ASD screening program in Spain. Beginning in 2005 an ASD screening program has been piloted in several paediatric outpatient clinics of Salamanca and Zamora and one year later in one health area of Madrid for the following two years.
Objectives:
- To analyze the validity properties of the Spanish-Spain version of the M-CHAT for early detection of ASD in Spain.
- To analyze the feasibility of a population based screening program for ASD in the public Health System in Spain.
Methods:
Period: From September 2005 to November 2010. Geographical area: Provinces of Salamanca, Zamora and Madrid, Spain. Population: All children of both genders aged 18 to 36 months, whose parents resided in the geographical area during the study period were selected when attending the mandatory measles, mumps and rubella vaccination program at age 18 months and/or the general well-baby check-up examination at age 24 months. Procedure: 2 phases: 1) M-CHAT Spain Version Validity Study. 2) Feasibility Study of a Population Based Screening Program using the M-CHAT in Spain. In both cases, screen positive on the M-CHAT led to the M-CHAT Follow-up Interview (FUI), screen positive on the FUI resulted in a diagnostic evaluation.
Results:
Number of paediatrician participants: 30 in Madrid, 39 in Salamanca and 18 in Zamora. Response rate= 8047/2910 (36.16%) in Madrid, 13633/4095 (30.03%) in Salamanca and 5860/2775 (47.35%) in Zamora. Data from M-CHAT Study in Madrid (April 2006- May 2008): 3317 MCHAT were administered to 2910 children 1567 girls and 1343 boys; 1871 at 18 months and 1446 at 24 months. 794 positive cases after the M-CHAT questionnaire; 35 positive cases confirmed with FUI and 35 evaluated cases (9 ASD, 15 GDD, 8 SLI, 3TD). Both data sample showed a PPV =.26 with 95% Confidence interval, [.11-.40] in Madrid [.15-.38] in Salamanca-Zamora. Data from Zamora and Salamanca Ongoing Screening Program: 8344 MCHAT have been administered so far to a total of 6870 children (3329 girls and 3541 boys; 4579 at 18 months and 3765 at 24 months). In Salamanca: 551 positive cases followed by the FUI; 31 FUI-positive cases evaluated: 8 ASD, 4 typically developing (TD), 15 Global developmental disorder (GDD), 3 specific language impairment (SLI), 1 Attention-Deficit/Hyperactivity Disorder (AD/HD). In Zamora: 521 positive cases followed by the FUI; 16 positive cases confirmed and evaluated: 7 ASD, 5 GDD, 3 SLI, 1 LD.
Conclusions:
The M-CHAT shows promise as a screening tool for developmental disorders in a population based screening program. Although there have been a high rate of false positives, this has facilitated an early start on effective intervention therapies for children with ASD as well as those with other disorders not previously identified. This work is still ongoing but so far it is an important contribution to the existing research on screening tools and identification of ASD at a young age.