Table 3.

Within- and between-group interaction effects on frailty, dialysis adequacy, and quality of life (n = 39)

Variable	Time (wk)	Exercise group (n = 18)	Control group (n = 21)	F	p-value	Repeated measures of ANCOVA
							F	p-value	η₂ (f)
Frailty (score)a	Baseline	2.22 ± 1.22	2.52 ± 0.87	0.35	0.56	Time	1.80	0.17d	0.048
	4th	1.33 ± 1.14c	2.95 ± 1.02	17.52	<0.001	Group	18.55	<0.001	0.340
	8th	1.11 ± 0.90c	3.05 ± 1.02	26.47	<0.001	T*G	21.74	<0.001d	0.376 (0.78)
	12th	0.94 ± 0.93c	3.10 ± 1.04	34.71	<0.001
Gait speed (m/sec)	Baseline	0.89 ± 0.22	0.83 ± 0.24	0.21	0.65	Time	8.18	0.003d	0.185
	4th	1.14 ± 0.30c	0.76 ± 0.22	11.88	0.001	Group	12.64	0.001	0.260
	8th	1.18 ± 0.31c	0.72 ± 0.19	20.23	<0.001	T*G	32.2	<0.001d	0.464 (0.93)
	12th	1.21 ± 0.31c	0.71 ± 0.19	24.26	<0.001
Grip strength (kg)	Baseline	23.58 ± 9.79	26.10 ± 8.83	1.27	0.27	Time	1.92	0.15d	0.051
	4th	24.00 ± 9.16	21.13 ± 9.51	0.18	0.68	Group	0.05	0.83	0.001
	8th	25.28 ± 8.45	22.40 ± 9.78	0.52	0.48	T*G	9.73	<0.001d	0.213 (0.52)
	12th	25.61 ± 8.88	22.07 ± 8.41	0.75	0.39
Exhaustion (vitality in SF-36, score)	Baseline	48.46 ± 12.80	46.24 ± 10.79	1.27	0.27	Time	1.17	0.33	0.031
	4th	53.16 ± 12.06	44.11 ± 9.78	7.60	0.009	Group	9.96	0.003	0.217
	8th	53.66 ± 8.99	41.68 ± 8.34	15.08	<0.001	T*G	2.27	0.09	0.059 (0.25)
	12th	53.82 ± 10.06	43.26 ± 6.80	12.38	0.001
Weight loss (BMI, kg/m2)	Baseline	21.55 ± 2.31	21.68 ± 3.06	0.03	0.88	Time	3.35	0.05d	0.085
	4th	21.53 ± 2.16	21.68 ± 3.02	0.03	0.86	Group	0.03	0.88	0.001
	8th	21.53 ± 2.01	21.64 ± 2.77	0.04	0.84	T*G	1.67	0.20d	0.044 (0.21)
	12th	21.58 ± 1.98	21.79 ± 3.01	0.24	0.63
SPPB (score)b	Baseline	10.67 ± 1.61	10.10 ± 2.02	0.07	0.79	Time	4.31	0.03d	0.009
	4th	11.56 ± 0.98c	9.52 ± 2.06	8.73	0.005	Group	8.73	0.006	0.142
	8th	11.72 ± 0.67c	9.86 ± 2.20	6.96	0.01	T*G	28.81	<0.001d	0.168 (0.45)
	12th	11.83 ± 0.51c	9.76 ± 2.28	9.89	0.003
Kt/V urea	Baseline	1.64 ± 0.19	1.67 ± 0.19	0.14	0.71	Time	0.46	0.67d	0.013
	4th	1.68 ± 0.24	1.71 ± 0.24	0.05	0.82	Group	0.29	0.59	0.008
	8th	1.70 ± 0.23	1.71 ± 0.28	0.14	0.71	T*G	2.85	0.05d	0.073 (0.28)
	12th	1.76 ± 0.30	1.64 ± 0.18	2.40	0.13
Physical component summary	Baseline	45.51 ± 6.48	44.50 ± 8.76	1.30	0.26	Time	5.59	0.003d	0.134
	4th	49.41 ± 4.94	43.81 ± 7.38	8.35	0.007	Group	8.52	0.006	0.191
	8th	50.31 ± 4.50	44.76 ± 6.88	7.41	0.01	T*G	1.98	0.13d	0.052 (0.23)
	12th	51.80 ± 4.51	42.79 ± 8.38	10.95	0.002
Mental component summary	Baseline	50.35 ± 11.04	49.81 ± 9.17	0.12	0.73	Time	0.90	0.97	0.003
	4th	53.98 ± 7.83c	45.22 ± 8.64	9.41	0.004	Group	5.11	0.03	0.124
	8th	53.24 ± 7.28c	44.95 ± 8.65	7.66	0.009	T*G	3.04	0.03	0.078 (0.29)
	12th	53.23 ± 8.60	48.95 ± 8.14	2.92	0.10

Data are expressed as mean ± standard deviation.

BMI, body mass index; Kt/V, K = dialyzer’s capacity to clear urea at the blood flow rate, t = treatment time, V = distribution volume of urea; SF-36, Short Form-36 tool; SPPB, short physical performance battery; T*G, time*group.

F is effect size calculated using the analysis of covariance (ANCOVA) model adjusted for dialysis vintage in G*Power (small = 0.10, medium = 0.25, large = 0.40); F-score calculated using ANCOVA adjusted by dialysis vintage (exercise group vs. control group).

Score range:

^a0–5,

^b0–12.

^cStatistically significant based on Bonferroni correction (p < 0.013);

^dGreenhouse-Geisser correction according to Mauchly’s sphericity test (p < 0.05).