Table 7 Meta-regression and subgroup analyses for significant mediators of heterogeneity

TUG

Intervention strategy of control groups

< 0.001

 TPEI

25

0.00%

0.609

− 0.448

− 0.641, − 0.255

 < 0.001

 NTI

14

81.61%

< 0.001

− 2.165

− 3.053, − 1.277

< 0.001

BBS

Intervention strategy of control groups

< 0.001

 TPEI

19

72.18%

< 0.001

2.133

1.213, 3.052

< 0.001

 NTI

6

30.27%

0.208

5.774

4.925, 6.624

< 0.001

6MWT

Intervention strategy of control groups

0.049

 TPEI

11

20.29%

0.233

22.671

16.847, 28.495

< 0.001

 NTI

7

33.54%

0.172

44.735

31.499, 57.970

< 0.001

Age

0.036

 Young-old adults

9

50.50%

0.016

31.595

19.611, 43.580

< 0.001

 Old-old adults

5

22.92%

0.254

27.723

19.708, 35.738

< 0.001

Health status

0.035

 Chronic obstructive pulmonary disease

1

n/a

1

8

− 11.579, 27.579

0.423

 Cognitive impairment

1

n/a

1

14.11

− 29.926, 58.146

0.53

 Frailty

2

75.27%

0.044

36.797

− 24.065, 97.66

0.236

 Health

2

17.56%

0.303

33.906

11.829, 55.982

0.003

 Mobility impairment

1

n/a

0.643

34.948

19.661, 50.235

< 0.001

 Parkinson’s disease

4

32.01%

0.184

46.618

29.601, 63.635

< 0.001

 Prostate cancer

1

n/a

1

55.3

12.216, 98.384

0.012

 Uncertain

2

n/a

0.556

26.221

17.917, 34.526

< 0.001

FES-I

Intervention strategy of control groups

0.021

 TPEI

6

0.00%

0.539

− 1.185

− 1.502, − 0.868

< 0.001

 NTI

4

0.00%

0.933

− 4.557

− 6.150, − 2.964

< 0.001