Table 2.
Methodological assessment using the Newcastle Ottawa quality assessment Scale (NOS).
| Studies | ltems | Quality | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | Score | ||
| Abate et al. (2011) [26] | + | + | + | + | + | + | + | + | + | 9/9 | B |
| Abate et al. (2010) [27] | + | + | + | + | + | + | + | + | + | 9/9 | B |
| Handa et al. (2003) [30] | + | + | − | + | + | − | + | + | + | 7/9 | B |
| Kang et al. (2010) [31] | + | + | − | − | + | + | − | + | + | 6/9 | B |
| Kim et al. (2013) [41] | − | + | − | + | − | − | + | + | − | 5/9 | B |
| Mavrikakis et al. (1989) [33] | + | + | + | + | + | + | + | + | + | 9/9 | B |
| Mavrikakis et al. (1991) [34] | + | + | + | + | + | + | + | + | + | 9/9 | B |
| Salek et al. (2010) [36] | + | + | + | + | − | − | + | + | + | 7/9 | B |
| Sattar et al. (1985) [42] | + | + | − | − | − | − | + | + | + | 5/9 | B |
| Shahet al. (2015) [38] | − | + | + | + | + | + | + | + | + | 8/9 | B |
| Shah et al. (2015) [39] | − | + | + | + | + | + | + | + | + | 8/9 | B |
| Siu et al. (2013) [40] | − | + | − | + | − | − | + | + | + | 6/9 | B |
| Selection 1: Is the case definition adequate? 2: Representativeness of the cases 3: Selection of controls. 4: Definition of controls | |||||||||||
| Comparability 5+6: Comparability of cases and controls on the basis of the the design or analysis | |||||||||||
| Exposure 7: Ascertainment of exposure 8: Same method of ascertainment for cases and controls 9: Non-Responserate | |||||||||||