Evaluating validity and reliability of Persian version of Supports Intensity Scale in adults with intellectual disability

Shifting paradigms regarding the ways to assess the support needs of people with intellectual disability in 1980 necessitates the design and development of appropriate tools more than ever. In this regard، American Association on Intellectual and Developmental Disabilities (AAIDD) developed Supports Intensity Scale (SIS) to respond the lack of an appropriate measurement tool. The aim of this study is the cultural adaptation and evaluation of psychometric properties of Supports Intensity Scale in adults with intellectual disability.

Validity of Persian version of SIS was assessed by Content validity. The reliability of the scale was evaluated using Cronbach''s alpha and test–retest reliability with a 3-week interval. In this study، the sample contained 43 adults (29 men and 14 women) with intellectual disability.

The content of the Persian version of SIS was approved by the experts. The Cronbach''s alpha reliability coefficients for the subscales ranged between 0. 80 and 0. 99. Also، Intraclass correlation coefficients ranged between 0. 90 and 0. 99 (P<0. 001). Furthermore، all Pearson correlation coefficients among the SIS subscales ranged between 0. 63 and 0. 98 (P<0. 01).

The results of this study indicated that the validity and reliability of the equivalent Persian version of SIS for identifying pattern and required supports intensity in adults with intellectual disability is acceptable.