Hemodialysis adequacy and quality of life: how do they relate?

There is clear evidence of a link between dialysis adequacy (as measured by urea kinetic modelling or urea reduction ratio) and such important clinical outcomes as morbidity and mortality. Evidence regarding the relationship between dialysis adequacy and quality of life outcomes is less clear. This paper reports the results of a study designed to answer the following research question: What is the impact of changing dialysis adequacy on functional status and well-being in a sample of new hemodialysis patients? The study employed a convenience sampling technique enrolling all willing new patients who started hemodialysis for a four-year period. The final sample size was 69. The adequacy of each new patient's dialysis prescription was determined by calculating Kt/V at one and three months following the start of dialysis. Changes to dialysis prescriptions were made, as necessary, to achieve a minimum Kt/V of 1.2. Each subject's quality of life was measured at the same time intervals, using two instruments. The first instrument, the SF-36, is a generic 36-item instrument designed to measure a range of functioning and well-being. The second instrument, the Kidney Disease Questionnaire (KDQ), is a disease-specific quality of life instrument designed for use with chronic hemodialysis patients. The results of this study demonstrated a significant positive relationship (p < .05) between Kt/V and four of five variables in the KDQ, and two of eight variables in the SF-36. These variables were predominantly in the social/emotional well-being domain.