Fig. 2

(a) Changes of Numerical Rating Scale (average) of fatigue at respective points during 12 months on HD day (a) and HD-free day (b). M0: During the period of standard HD, and within 2 weeks before commencement of E-HD. M1, M3, M6, M12: 1st month (M1), 3rd months (M3), 6th months (M6), and 12th months (M12) after commencement of E-HD. E-HD: electrolyzed water hemodialysis. A: Group A; presenting fatigue with decreased activities of daily life (ADL) defined by Numerical Rating Scale (NRS) 4 or more: n = 25. B: Group B; presenting fatigue without decreased ADL defined by NRS 2 or 3: n = 24. C: Group-C; no fatigue defined by NRS 0 or 1: n = 32. Group-A on HD day (a); 5.56 ± 1.33 (M0), 4.48 ± 1.96 (M1), 4.92 ± 1.87 (M3), 4.72 ± 1.67 (M6), 3.56 ± 2.47 (M12) (average +/- standard deviation). A significant change was observed on HD day (* p < 0.05; M0 vs. M12, by repeated-measure-ANOVA). Group-A on HD-free day (b); 3.36 ± 2.20 (M0), 1.80 ± 1.78 (M1), 2.28 ± 2.01 (M3), 2.40 ± 1.98 (M6), 1.92 ± 2.48 (M12) (average +/- standard deviation). No statistical change was observed on HD-free day. (Bars of Group A denote 95% confidence intervals). (b) Changes of Numerical Rating Scale (average) of fatigue at respective points during 12 months on HD day (a) and HD-free day (b) in Group A1 and A2. A1: chronic persistent fatigue (NRS 4 or more) on both HD and HD-free days at baseline (Month 0): n = 11. A2: as having fatigue (NRS 4 or more) only on HD days at baseline (Month 0): n = 14 (Bars of Group A1 and 2 denote 95% confidence intervals). In Group A1, no statistical change was observed on HD day, while there was a significant change in HD-free day (* p = 0.017; M0 vs. M1, by repeated-measure-ANOVA). In Group A2, there was a significant change in HD day (* p = 0.018; M0 vs. M12, by repeated-measure-ANOVA), no statistical change was observed on HD-free day. There were significant differences between A1 and A2 at baseline (M0) on HD and HD-free days (# p = 0.004, ## p < 0.001), respectively. A significant difference was observed at M3 on HD-free day between the two groups (### p = 0.001). Besides them, no statistical differences were observed between the groups.