Letter to the Editor in Response to the Article “Clinical Outcomes With Medium Cut-Off Versus High-Flux Hemodialysis Membranes: A Systematic Review and Meta-Analysis”

Dear Sir,

Dr Kandi and colleagues reported clinical outcomes with medium cut-off (MCO) versus high-flux hemodialysis membranes using 22 studies (6 randomized and 16 nonrandomized studies). The authors concluded with predominantly moderate certainty that MCO dialyzer improves several patient-important outcomes. However, we have some concerns regarding the results of the study. ¹

First, the authors stated that MCO dialysis likely reduces pruritis, with mean difference 4.38 lower compared with high-flux dialysis in page 11 and in table 2 on page 6. Whereas, regarding reference of this data, mean difference is lower than 4.38 between 2 membranes (MCO membrane: 6.92 ± 5.98 vs high-flux membrane: 9.92 ± 8.23). ² In addition, there is no significant difference in pruritis between 2 types of membranes (P: .152). In conclusion, it is not possible to conclude that MCO dialysis likely reduces pruritis.

Second, in table 2 on page 6 and in page 11, the authors stated that MCO dialysis reduced recovery time by –420 minutes (high-flux membrane: 600 minutes vs MCO membrane: 180 minutes). However, in reference of this data, the median recovery is 210 minutes initially and then 105 minutes at 12th month. ³ The authors possibly used 25th and 75th percentile values in figure 1 on page 3 for calculating the difference between recovery times of 2 types of membranes. In conclusion, it is not possible to conclude that MCO dialysis reduced recovery time by –420 minutes.