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

Background Duke Activity Status Index (DASI) is a widely used tool to assess functional capacity among patients, but there is no Sinhala version validated for patients in Sri Lanka. This study aimed to cross-culturally adapt and test the validity and reliability of the Sinhala version of DASI (DASI-S). Methods The translation and cross-cultural adaptation of the DASI questionnaire were conducted following the standard guidelines. It was pre-tested on ten pre-operative patients and further modified. The construct validity and reliability of DASI-S were evaluated by administering the modified final DASI-S, which comprised 12 items, along with the physical functioning sub-scale of the 36-item short-form health survey (SF-36), consisting of 10 items to eighty-one patients who were awaiting non-cardiac surgeries at university surgical wards, National Hospital of Sri Lanka (NHSL), and Colombo North Teaching Hospital (CNTH), Sri Lanka. Reliability was assessed through Cronbach alpha, while the validity was evaluated using factor analysis and Spearman's correlation. The ethical approval was obtained from the Ethics Review Committee, Faculty of Medicine, University of Colombo, Sri Lanka. Results The mean age of the participants was 46.2 (+/- 16.6) years and the majority were females (54.3%). The mean height, weight, and body mass index of the sample were 160.5 (+/- 9.6) cm, 60.3 (+/- 11.9) kg, and 23.4 (+/- 4.5) kgm(-2) respectively. The Cronbach's alpha coefficient for the internal consistency of DASI-S was 0.861. The concurrent validity of DASI-S was substantiated by positively correlating (p < 0.01, r s = 0.466) with the physical sub-scale of SF-36. There was a significant difference (p < 0.01) in the total score of DASI-S between the two age groups. Conclusions Sinhala 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.