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 |