Table 2.
Quality assessment of reviewed case–control studies
| Study | Quality indications of Newcastle–Ottawa scale | Total | |||||||
|---|---|---|---|---|---|---|---|---|---|
| A | B | C | D | E | F | G | H | ||
| Ma et al., 2005 | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 1 | 7 |
| Wozniak et al., 2006 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 8 |
| Sowell et al., 2008 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 8 |
| Lebel, Rasmussen, et al., 2008 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 8 |
| Fryer et al., 2009 | 1 | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 7 |
| Li et al., 2009 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 8 |
| Wozniak et al., 2009 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 8 |
| Lebel et al., 2010 | Case series study | ||||||||
| Santhanam et al., 2011 | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 1 | 7 |
| Spottiswoode et al., 2011 | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 1 | 7 |
| Wozniak et al., 2011 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 8 |
| Colby et al., 2012 | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 1 | 7 |
| Treit et al., 2013 | Longitudinal study | ||||||||
| Green et al., 2013 | Case series study | ||||||||
| Paolozza, Rasmussen, et al., 2014a, Paolozza, Rasmussen, et al., 2014b | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 8 |
| Fan et al., 2016 | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 1 | 7 |
| Taylor et al., 2015 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 1 | 6 |
| Donald et al., 2015 | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 1 | 7 |
| O'Conaill et al., 2015 | 1 | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 7 |
| Fan et al., 2016 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 1 | 6 |
| Paolozza et al., 2017 | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 1 | 7 |
| Treit et al., 2017 | 1 | 1 | 0 | 1 | 1 | 1 | 1 | 1 | 7 |
| Uban et al., 2017 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 1 | 6 |
A. Adequate definition of case; B. Representativeness of Cases; C. Selection of controls; D. Definition of controls; E. Control for important factor or additional factor; F. Exposure Assessment; G. Same method of ascertainment for cases and controls; H. Nonresponse rate.