Translation, cross-cultural adaptation, and validation of the Duke Activity Status Index (DASI) to Sinhala language: Translation, cross-cultural adaptation, and validation study

Background Duke Activity Status Index (DASI) is a widely used tool to assess functional capacity among patients, but there is no Sri Lankan version validated for patients in Sri Lanka. This study aimed to cross culturally adapt and test validity and reliability of Sinhala version of DASI (DASI-SL). Methods The questionnaire was translated using forward and backward translation methods and cultural adaptation was conducted. It was pretested on ten preoperative patients and further modified. Construct validity and reliability of DASI-SL was assessed by administering the modified final DASI-SL on eighty-one patients who were awaiting non-cardiac surgeries at university surgical wards, National Hospital of Sri Lanka, and Colombo North Teaching Hospital Sri Lanka. Results The Cronbach's α coefficient for the internal consistency of DASI-SL was 0.861. The concurrent validity of DASI-SL was substantiated by positively correlating (p < 0.01, r s = 0.466) with the physical subscale of SF-36. There was a significant difference (p < 0.01) in the total score of DASI-SL between two age groups. Conclusions The Sri Lankan version of the DASI appears to be a valid, reliable and easy to administer tool to assess functional capacity among patients who are awaiting non-cardiac surgeries.