Hindi version of the lower extremity functional scale: a study of translation, validation and cross-cultural adaptation

Abstract

BACKGROUND: Lower Extremity Function Scale (LEFS) serves as a patient-reported outcome measure, used to evaluate the functional status of lower extremity in different musculoskeletal conditions. It was originally developed in English language (E-LEFS) and numerous translations in different languages are available to measure its usability among different cultures. OBJECTIVES: To translate the English version of the Lower Extremity Function Scale (E-LEFS) into Hindi language and to evaluate its content validity, cross-cultural adaptation along with the concurrent validity and reliability. METHOD: Process of forward and backward translation was carried out by two bilingual translators and a physiotherapist after obtaining developer’s approval, for which the Beaton guidelines were used. For the content validation, Delphi method of was employed in which 12 field experts of more than 5 years of experience participated. Cultural adaptation procedures were then carried out with 12 patients, who reported in out-patient department of the hospital through convenience sampling who were asked about whether the H-LEFS was well understood by the patients. Their responses were recorded as positive and negative responses. This process was followed by concurrent validation which was conducted by comparing the scores with the SF-36 scale, involving 30 patients with activity limitation in their daily life. Lastly, 50 patients were recruited for intra-rater reliability testing. RESULT: The scale was successfully translated and verified by the bi-lingual language experts. Content validity came out to be significant with each item scoring more than 0.92. Nearly all items, excluding item no. 8, 16, 17, 18, and 19 received universal agreement with a content validity ratio of 1. The average scale-level validity stood at 0.98, indicating excellent level of validity and the scale was found to be well adapted by the native people as out of 12 patients, 10 patients provided 100% positive response. Concurrent validation using Pearson’s correlation coefficient came out excellent with the values of 0.993 for E-LEFS and 0.890 for SF-36. Cronbach's alpha and ICC values were calculated as 1.00 for Intra-rater reliability. CONCLUSION: LEFS was well translated into Hindi language with an excellent content and concurrent validity and is found to be highly reliable. Hence, it is recommended for the usage of native Hindi speaking population.