Cross-cultural adaptation, validation and reliability of the South Indian (Kannada) version of the kidney disease and quality of life (KDQOL-36) instrument

Health-related quality of life is an essential aspect concerned with the treatment outcomes. The main objective of the study is to evaluate the validity and reliability of the South Indian (Kannada) version of the Kidney Disease and Quality of Life-36 (KDQOL-36) instrument for hemodialysis (HD) patients. The KDQOL-36 instrument was validated by the committee of experts consisting of healthcare providers such as nephrologists (three), senior HD staff nurse (one) and clinical pharmacist (one). The measurement properties such as variability, reliability and validity were determined by administering the questionnaire to 82 patients on HD who were randomly selected from the HD units of three hospitals. The test and retest methods were used for reliability. Test-re-test reliability was assessed with a subsample of 45 patients by two administrations of the KDQOL-36 seven days apart. Data were collected through a face-to-face interview. It was evaluated computing intraclass correlation coefficients (ICC) and internal consistency estimated by computing Cronbach's-alfa. Reliability of each Kannada version of the KDQOL-36 sub-scale (symptoms/problems, burden of kidney disease, effects of kidney disease, physical component score [PCS] and mental component score [MCS] was good (Cronbach's-alfa >0.7, ranging from 0.72 to 0.77). The ICC ranged from 0.83 to 0.99 and the 95% confidence interval was 0.76-0.99 for test-retest of the KDQOL-36. The reliability measured with Cronbach's alfa, which was more than 0.72 and ICC ranged from 0.83 to 0.99, indicating that the Kannada version of the KDQOL-36 is reliable and valid for evaluating the health-related quality of life in Kannada-speaking HD patients.