Psychometric Evaluation of the Kidney Disease Quality of Life 36-Item Survey Instrument (KDQOL-36): A Comparison Between Older and Younger Adults Receiving Dialysis

Abstract

Medicare requires that dialysis units assess quality of life in all patients annually using the Kidney Disease Quality of Life 36-item survey instrument (KDQOL-36). However, whether the KDQOL-36 is a valid instrument for older adults receiving dialysis is not known. The objective of this study was to evaluate the reliability and validity of the KDQOL-36 in both older and younger patients receiving dialysis. We used KDQOL-36 item responses from a nationally representative sample of 3500 older (≥ 75 years) and 500 younger (ages 21 to 74 years) patients receiving dialysis in 2012. We assessed subscale means, ceiling/floor effects, internal consistency reliability, and construct validity. Results demonstrated that the KDQOL-36 has comparable reliability and validity in older and younger adults receiving dialysis.