Validity Question

Nalk, 2017

Wheeler, 2016

Hollis, 2015

Basile, 2006

Wagner, 2006

Oberhelman, 2013

Hollis, 2004

1. Was research question stated clearly?

Yes

Yes

Yes

Yes

Yes

Yes

Yes

2. Was selection of study subjects free from bias?

Yes

Yes

Yes

No

No

Yes

Yes

3. Were study groups comparable?

Yes

Yes

Yes

Yes

Yes

Yes

Yes

4. Was method of handling withdrawals described?

n/a

No

n/a

No

Yes

n/a

n/a

5. Was blinding used to prevent introduction of bias?

Yes

Yes

Yes

Yes

Yes

No

No

6. Were intervention and comparison described in detail?

Yes

Yes

Yes

Yes

Yes

Yes

Yes

7. Were outcomes clearly defined and the measurements valid and reliable?

Yes

Yes

Yes

Yes

Yes

Yes

Yes

8. Was the statistical analysis appropriate for the study design and type of outcome indicators?

Yes

Yes

Yes

Yes

Yes

Yes

Yes

9. Are conclusions supported by results with biases and limitations taken into consideration?

Yes

Yes

Yes

Yes

Yes

Yes

Yes

10. Is bias due to study’s funding or sponsorship unlikely?

Yes

Yes

Yes

Yes

Yes

Yes

Yes