Table 2.
Summary of the quality ratings for the eligible studies using the Newcastle-Ottawa Quality Assessment Scale for case-control studies.
| First author [reference] | Selection | Comparability | Exposure | Total points | Ratinga |
|---|---|---|---|---|---|
| AbdulWahab [69] | 2 | 1 | 3 | 6 | High |
| Ambroszkiewicz [60] | 3 | 2 | 2 | 7 | High |
| Antus [74] | 3 | 0 | 1 | 4 | Moderate |
| Aris [68] | 2 | 1 | 3 | 6 | High |
| Back [42] | 1 | 1 | 2 | 4 | Moderate |
| Bernardi [39] | 2 | 1 | 2 | 5 | Moderate |
| Best [71] | 1 | 1 | 3 | 5 | Moderate |
| Cobanoglu [66] | 2 | 2 | 3 | 7 | High |
| Collins [75] | 3 | 0 | 3 | 6 | High |
| Dominguez [64] | 1 | 1 | 1 | 3 | Moderate |
| Durieu [43] | 0 | 0 | 2 | 2 | Low |
| Eichler [144] | 2 | 0 | 1 | 3 | Moderate |
| Hahn [48] | 2 | 2 | 3 | 7 | High |
| Hubbard [55] | 2 | 0 | 1 | 3 | Moderate |
| Hung [89] | 3 | 0 | 1 | 4 | Moderate |
| Jacob [49] | 2 | 0 | 2 | 4 | Moderate |
| James [38] | 0 | 0 | 2 | 2 | Low |
| Kearns [46] | 1 | 1 | 2 | 4 | Moderate |
| Koller [145] | 1 | 0 | 2 | 3 | Moderate |
| Koller [146] | 0 | 0 | 2 | 2 | Low |
| Koller [147] | 1 | 0 | 2 | 3 | Moderate |
| Konstantinidis [139] | 1 | 1 | 3 | 5 | Moderate |
| Lagrange-Puget [7] | 2 | 0 | 2 | 4 | Moderate |
| Lands [73] | 1 | 0 | 2 | 3 | Moderate |
| Lee [45] | 2 | 0 | 1 | 3 | Moderate |
| Madarasi [61] | 1 | 1 | 2 | 4 | Moderate |
| Mangione [51] | 0 | 1 | 3 | 4 | Moderate |
| McGrath [54] | 3 | 2 | 3 | 8 | High |
| Mocchegiani [47] | 1 | 1 | 3 | 5 | Moderate |
| Nicolaidou [44] | 2 | 0 | 3 | 5 | Moderate |
| Olveira [58] | 1 | 2 | 3 | 6 | High |
| Olveira [52] | 0 | 1 | 3 | 4 | Moderate |
| Oudshoorn [63] | 0 | 1 | 3 | 4 | Moderate |
| Percival [70] | 3 | 1 | 3 | 7 | High |
| Reiter [65] | 3 | 2 | 3 | 8 | High |
| Rovner [67] | 3 | 0 | 3 | 6 | High |
| Sadowska-Bartosz [53] | 1 | 0 | 3 | 4 | Moderate |
| Sadowska-Woda [72] | 0 | 1 | 3 | 4 | Moderate |
| Schupp [57] | 2 | 2 | 3 | 7 | High |
| Sidlova [88] | 2 | 0 | 3 | 5 | Moderate |
| Stead [50] | 2 | 1 | 2 | 5 | Moderate |
| Tauber [143] | 0 | 1 | 2 | 3 | Moderate |
| Tirouvanziam [40] | 1 | 0 | 3 | 4 | Moderate |
| Turowski [140] | 2 | 0 | 3 | 5 | Moderate |
| Vaisman [62] | 0 | 1 | 3 | 4 | Moderate |
| Van Biervliet [142] | 2 | 0 | 3 | 5 | Moderate |
| Winklhofer-Roob [56] | 2 | 0 | 2 | 4 | Moderate |
| Wood [41] | 4 | 2 | 3 | 9 | High |
| Yadav [59] | 2 | 1 | 3 | 6 | High |
a
Studies scoring 0–2 were considered low quality, studies scoring 3–5 were considered moderate quality and studies scoring 6–8 points were considered high quality.