Table 3 Results of the stratified meta-analyses

All trials, physical function

− 0.50

− 0.61, − 0.40

64%

0.07

–

Fixed-effect model

− 0.53

− 0.57, − 0.45

 Intervention

0.08

0.42

Pharmacological

− 0.53

− 0.64, − 0.42

Non-pharmacological

− 0.40

− 0.74, − 0.05

 Intervention

0.08

0.44

Biological treatment

− 0.57

− 0.68, − 0.46

Other treatment

− 0.46

− 0.63, − 0.28

All trials, pain

− 0.48

− 0.66, − 0.30

87%

0.28

–

Fixed-effect model

− 0.50

− 0.56, − 0.44

 Intervention

0.19

< 0.001

Pharmacological

− 0.64

− 0.78, − 0.49

Non-pharmacological

0.26

− 0.20, 0.72

 Intervention

0.29

0.28

Biological treatment

− 0.64

− 0.80, − 0-49

Other treatment

− 0.41

− 0.68, − 0.14

All trials, spinal mobility

− 0.32

− 0.48, − 0.17

83%

0.21

–

Fixed-effect model

− 0.32

− 0.38, − 0.26

 Intervention

0.19

0.28

Pharmacological

− 0.35

− 0.51, − 0.19

Non-pharmacological

− 0.02

− 0.61, 0.56

 Intervention

0.33

0.65

Biological treatment

− 0.31

− 0.47, − 0.15

Other treatment

− 0.28

− 0.52, − 0.03

All trials, spinal stiffness

− 0.59

− 0.74, − 0.44

75%

0.14

–

Fixed-effect model

− 0.61

− 0.68, − 0.54

 Intervention

0.18

0.95

Pharmacological

− 0.60

− 0.76, − 0.44

Non-pharmacological

− 0.61

− 0.93, − 0.29

 Intervention

0.16

0.34

Biological treatment

− 0.77

− 0.88, − 0.65

Other treatment

− 0.55

− 0.75, − 0.35

All trials, PGA

− 0.71

− 0.89, − 0.54

83%

0.18

–

Fixed-effect model

− 0.74

− 0.81, − 0.67

 Intervention

0.19

0.15

Pharmacological

− 0.77

− 0.96, − 0.59

Non-pharmacological

− 0.37

− 0.81, 0.07

 Intervention

Biological treatment

− 0.84

− 1.09, − 0.60

0.20

0.23

Other treatment

− 0.60

− 0.87, − 0.34

All trials, PJ/E

0.05

− 0.11, 0.22

68%

0.06

–

Fixed-effect model

0.00

− 0.08, 0.09

 Intervention

0.00

< 0.001

Pharmacological

− 0.06

− 0.15, 0.03

Non-pharmacological

0.99

0.63, 1.35

 Intervention

0.04

0.02

Biological treatment

− 0.10

− 0.20, − 0.01

Other treatment

0.27

− 0.10, 0.64

All trials, acute phase reactants

− 0.51

− 0.70, − 0.32

84%

0.22

–

Fixed-effect model

− 0.62

− 0.69, − 0.55

 Intervention

–

–

Pharmacological

− 0.51

− 0.70, − 0.32

Non-pharmacological

–

–

 Intervention

0.12

0.001

Biological treatment

− 0.77

− 1.02, − 0.52

Other treatment

− 0.22

− 0.37, − 0.07

−0.07

All trials, spine radiographs

0.96

0.22, 1.69

–

–

–

Fixed-effect model

–

–

 Intervention

–

–

Pharmacological

–

–

Non-pharmacological

–

–

 Intervention

Biological treatment

Other treatment

0.96

0.22, 1.69

All trials, fatigue

− 0.65

− 0.82, − 0.48

0%

0.00

–

Fixed-effect model

− 0.65

− 0.82, − 0.48

 Intervention

–

–

Pharmacological

− 0.65

− 0.82, − 0.48

Non-pharmacological

–

–

 Intervention

–

–

Biological treatment

− 0.65

− 0.82, −0.48

Other treatment