Table 1 Quality assessment of included studies

Ade-Oshifogun

1

3

1

2

1

2

2

Arnold

1

2

1

1

1

2

2

Baker

1

1

1

1

1

2

1

Brunault

1

2

2

1

1

1

1

Carlson

1

2

3

2

1

2

2

Cosby

1

3

3

2

1

1

3

Eilayyan

1

2

2

2

1

2

2

Halvorsrud

1

1

2

2

1

1

2

Heo

1

1

1

1

1

1

1

Hofer

1

2

1

1

1

1

1

Kanters

1

2

1

1

1

1

2

Krethong

1

3

1

2

1

2

2

Mathisen

1

1

2

1

1

1

1

Mayo

1

2

3

2

1

1

2

Nokes

1

3

2

1

1

1

2

Phaladze

1

3

2

2

1

2

2

Portillo

1

3

1

2

1

2

2

Saengsiri

1

1

2

3

1

1

2

Santos

1

1

1

1

1

2

2

Schulz

2

2

1

1

1

2

2

Shiu

1

3

1

2

1

1

2

Sousa (1999)

1

3

1

2

1

2

2

Sousa (2006)

1

2

2

2

1

2

2

Ulvik

1

3

2

2

1

2

2

Wettergren

2

2

1

1

1

2

2

Wyrwich

1

2

1

1

1

2

1