Z. Zhou et al.
Table III. Assessment of bias risk in individual study
Items of PEDro scale
Total
Studies 1
2 3 4 5 6 7 8 9 10 11 score
Zhu et al. (32)
Zhao et al. (33)
Wang et al. (34) Yes 0 0 1 0 0 0 1 0 1
Yes 1 0 1 0 0 0 1 0 1
Yes 1 0 1 0 0 0 1 0 1 1
1
1 4
5
5
Zhang et al. (35)
Li et al. (36)
Bao et al. (37)
Li et al. (38)
Zhang et al. (39)
Tang et al. (40)
Meng et al. (41)
Youngwanichsetha et al. (42)
Ahn et al. (43)
Xiao et al. (44)
Wu et al. (45)
Wang et al. (46)
Zhang et al. (47)
Lam et al. (48)
Tsang and Orr et al. (49–51)
Jiang et al. (52)
Yu et al. (53)
Yan et al. (54)
Kan et al. (55)
Wang et al. (56) Yes
Yes
Yes
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Yes 1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1 5
4
5
5
5
5
5
6
4
5
5
5
5
7
9
5
5
5
5
4
1
0
1
1
1
1
1
1
0
1
1
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
1
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
1
1
0
0
0
0
0
1
1
1
1
1
1
1
1
0
1
1
1
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Items of PEDro scale, 1: specification of inclusion criteria; 2: random distribution;
3: allocation concealment; 4: similarity at baseline; 5: blind participants; 6:
blind therapists; 7: blind assessor; 8: over 85% subjects at follow-up; 9:
intention-to-treatment analysis; 10: comparison between groups; 11: point
estimates and variability.
For item 2–11: 1 refers to a satisfied criterion; 0 indicates the criterion is
unclear or unsatisfied.
Fasting insulin. Eight studies (33, 38, 41, 45, 47, 52, 53,
55) evaluated the impact of tai chi on FIN. The pooled
analysis suggested that tai chi failed to show favourable
influence on FIN (SMD –0.32; 95% CI –0.71 to 0.07;
p = 0.110; heterogeneity, I 2 = 73.3%, p < 0.001; Fig. 4).
Insulin resistance. The effects of tai chi on IR measured
by HOMA were reported in 5 studies (33, 35, 41, 48,
49). A fixed-effects pooled analysis showed favoura-
ble effects of tai chi on reducing IR (MD –0.41; 95%
CI –0.78 to –0.04; p = 0.029; heterogeneity I 2 = 0.0%,
p = 0.5; Fig. 5).
Total cholesterol. Ten studies (32, 33, 35, 37, 38, 41,
47, 48, 52, 55) evaluated the effects of tai chi on TC. A
random-effects pooled analysis demonstrated positive
effects of tai chi on decreasing TC (SMD –0.59; 95%
CI –0.90 to –0.27; p < 0.001; heterogeneity, I 2 = 66.6%,
p = 0.001; Fig. 6).
Body mass index. Seven studies (33, 37, 38, 42, 49,
55, 56) compared the effects of tai chi on BMI with
control group. A fixed-effects pooled analysis indicated
that there was a statistically significant reduction in
BMI (MD –0.82 kg/m 2 ; 95% CI –1.28 to –0.37 kg/m 2 ;
p < 0.001; heterogeneity, I 2 = 26.3%, p = 0.228; Fig. 7A).
410
Fig. 2. Forest plot of the effects of tai chi on fasting plasma glucose. StudyID: study reference; Tn: number of participants in treatment group;
Cn: number of participants in control group; SMD: standardized mean difference; 95% CI: 95% confidence interval.
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