Reliability and validity studies of the Turkish version of autism behavior checklist

According to the study findings in recent years, Autism Spectrum Disorders (ASD), while considered as low incident occurrences in the past, have lost this characteristic. Today, ASD have more prevalence than many other developmental disabilities, which force countries to take precautions about early assessment and education. Since there are no reliable biological tests or medical imaging methods to diagnose ASD, it can only be diagnosed through the observation and reporting the individual. Especially in abroad, standard instruments assist specialists during the assessment process and are used extensively. In our country, while the use of these instruments has been increased in recent years, it is difficult to say that the number and use of these tools for screening and diagnosis are sufficient. Autism Behavior Checklist, developed in United States of America, is a reliable and valid instrument for ASD, which is in use for many years. Since this instrument can be completed in a short time and has a simple use, it is considered suitable for the conditions of our country and aimed for adaptation to Turkish. The adaptation studies of the instrument began with the language equivalence, however because of the occurring needs it is decided to make some additions on ODKL which are not present in the original version. Additional items to be used in the diagnosis of ASD are added to the tool and explanations are written under all items. Findings of the pilot study after these changes showed that the instrument is suitable for the main study. The sample of the main study consists of 969 pupils from 21 cities who have OSB diagnoses. Besides, in order to be evaluated in validity analysis, data were collected from 164 students with intellectual disability. The validity analysis which were conducted in the study were; factor analysis, determination of correlation coefficients with Gilliam Autism Rating Scale 2 Turkish Version (GARS 2-TV) and determination of instrument's discrimination between OSB and intellectual disabilities. The reliability studies were; test-retest analysis, internal consistency and item coefficient analysis. After that, analyses were conducted to see whether ABC scores differed according to the variables of age, sex, intellectual disability and speech. Finally, percentiles and cut off scores were determined. Factor analysis revealed that ABC's main items (49 items) can be grouped under a two factor structure. Confirmatory factor analysis supported this finding. Eight items out of 57 items in the instrument were eliminated factor analysis. The correlation level of the instrument with Turkish Version of GARS-2 and the discrimination power between OSB and groups with intellectual disability were found to be satisfying. While no difference between age and sex were observed, intellectual disability and speech variables are differed according to ABC scores. The results of the reliability analysis showed that test retest reliability, internal consistency coefficients and item coefficients met the necessary requirements. Finally, score equivalents of percentiles in order to use the instrument with DSM V, were determined. According to results of these studies, it can be commented that ABC is a diagnostic instrument which have the required reliability-validity levels to be used in Turkey.