Impact of Medium Cut-Off Dialyzers on Patient-Reported Outcomes: COREXH Registry
<b><i>Introduction:</i></b> A new generation of hemodialysis (HD) membranes called medium cut-off (MCO) membranes possesses enhanced capacities for middle molecule clearance, which have been associated with adverse outcomes in this population. These improvements could potentially positively impact patient-reported outcomes (PROs). <b><i>Objective:</i></b> The objective of this study was to evaluate the impact of MCO membranes on PROs in a cohort of HD patients in Colombia. <b><i>Methods:</i></b> This was a prospective, multicenter, observational cohort study of 992 patients from 12 renal clinics in Colombia who were switched from high-flux HD to MCO therapy and observed for 12 months. Changes in Kidney Disease Quality of Life 36-Item Short Form Survey (KDQoL-SF36) domains, Dialysis Symptom Index (DSI), and restless legs syndrome (RLS) 12 months after switching to MCO membranes were compared with time on high-flux membranes. Repeated measures of ANOVA were used to evaluate changes in KDQoL-SF36 scores; severity scoring was used to assess DSI changes over time; Cochran’s Q test was used to evaluate changes in frequency of diagnostic criteria of RLS. <b><i>Results:</i></b> During 12 months of follow-up, 3 of 5 KDQoL-SF36 domains improved compared with baseline: symptoms (<i>p</i> < 0.0001), effects of kidney disease (<i>p</i> < 0.0001), and burden of kidney disease (<i>p</i> < 0.001). The proportion of patients diagnosed with RLS significantly decreased from 22.1% at baseline to 10% at 12 months (<i>p</i> < 0.0001). No significant differences in the number of symptoms (DSI, <i>p =</i> 0.1) were observed, although their severity decreased (<i>p</i> = 0.009). <b><i>Conclusions:</i></b> In conventional HD patients, the expanded clearance of large middle molecules with MCO-HD membranes was associated with higher health-related quality of life scores and a decrease in the prevalence of RLS.