Table 3 Results of linear and logistic regression analyses

Sample size

National collaboration

− 4.89

–

0.75

− 34.61, 24.84

International collaboration within the same continent

14.54

–

0.56

− 34.47, 63.55

International collaboration within different continents

0.17

–

0.1

− 34.93, 44.27

National collaboration

70.26

–

0.00*

33.59, 106.93

International collaboration within the same continent

89.58

–

0.31

− 84.09, 263.25

International collaboration within different continents

− 30.42

–

0.73

− 204.09, 143.25

Funding status

National collaboration

–

2.37

0.1

0.85, 6.57

International collaboration within the same continent

–

1.00

–

–

International collaboration within different continents

–

5.54

0.13

0.62, 49.52

Study conduct collaboration

–

0.77

0.7

0.21, 3.43