Table 5.

Comparison of RI among four groups

	Group C (n = 43)	Group P (n = 45)	Group D (n = 43)	Group PD (n = 44)	statistic	P value
T0	0.37 ± 0.24	0.37 ± 0.28	0.39 ± 0.18	0.35 ± 0.21	0.218	0.884
T1	0.38 ± 0.26	0.32 ± 0.18	0.37 ± 0.17	0.32 ± 0.18	2.210	0.092
T2	0.36 ± 0.20	0.31 ± 0.14	0.37 ± 0.17	0.30 ± 0.10	2.050	0.109
T3	–	–	–	–
T4	1.21 ± 0.53#	0.94 ± 0.59#a	0.96 ± 0.49#a	0.74 ± 0.33#bcd	6.620	< 0.001
T5	1.08 ± 0.73#	0.78 ± 0.64#a	0.78 ± 0.48#a	0.67 ± 0.44#b	3.999	0.009
T6	0.87 ± 0.93#	0.59 ± 0.39#	0.65 ± 0.74#	0.47 ± 0.50#	2.237	0.089

Compared with T0, ^#P < 0.01; compared with group C, ^aP < 0.05 and ^bP < 0.01; compared with group P, ^cP < 0.05; compared with group D, ^dP < 0.05