Cross-cultural adaption, reliability and validity of an Indian (Tamil) version for the Shoulder Pain and Disability Index

The objective of the study was to cross-culturally adapt the Shoulder Pain and Disability Index (SPADI) into a regional Indian language (Tamil) and to test the reliability and linguistic validity of the index in Tamil-speaking Indian participants. Cross-cultural adaptation and psychometric testing of SPADI was undertaken at the Outpatient Physiotherapy Department of the Sri Ramachandra University Hospital in Chennai, India. The Test-retest reliability was quantified using the interclass correlation coefficient (ICC) and Cronbach alpha was calculated to assess internal consistency of the Tamil questionnaire. The construct validity was assessed using Spearman rank correlation coefficients. The reliability of the total Tamil SPADI and its subsets (Intraclass correlation coefficient >0.90) were found to be higher than that of the English SPADI and the German SPADI in this population. The internal consistency of the Tamil SPADI (Cronbach's alpha >0.95) was slightly higher than the English and the German versions. Thus, the cross-culturally adapted version of the English SPADI into a regional Indian language (Tamil) is easy to use and is a reliable and valid measure of shoulder pain and disability in the Tamil speaking population.