Table 4

Newcastle-Ottawa scale for included studies

First author	Representative ness ofexposed cohort	Selection of non-exposedcohort	Ascertainment of exposure	Outcome of interestaccounted for	Age/gender	Other factors	Ascertainment of outcomes	Length of follow-up	Adequacy of follow-up	Quality of study
Rice J.	*	*	*	*	*		*	*	*	Good
Ikari T.	*	*	*	*	*	*		*	*	Good
Dogbey D.M.	*	*	*	*	*	*	*	*	*	Good
Moor C.C.	*	*	*	*	*	*	*	*	*	Good
Gonzalez-Jaramillo V.	*	*	*	*	*	*	*	*	*	Good
Tripp D.	*	*	*	*	*	*	*	*	*	Good
Flierman I.	*	*	*	*			*	*	*	Poor
Kim S.H.		*	*	*		*		*	*	Good
Ouchi K.	*	*	*	*	*	*	*	*		Good
Ermers D.J.M.	*	*	*	*			*	*	*	Poor
Yarnell C.	*	*	*	*	*	*	*	*	*	Good
Van WijmenM.P.S.	*	*	*	*	*	*	*	*	*	Good
Ramer S.J.	*	*	*	*	*	*	*	*	*	Good
Lai C.-F.		*	*	*	*	*			*	Poor
Rauh L.A.	*	*	*	*	*	*	*	*	*	Good
Verhoef M.J.	*	*	*	*			*	*	*	Poor
Maes H.	*	*	*	*	*	*	*	*	*	Good
Yen Y.-F.	*	*	*	*	*	*	*		*	Good
Aaronson E.L.	*	*	*	*		*	*		*	Good
Schmidt R.J.	*	*	*	*	*	*	*	*	*	Good
Lakin J.R.	*	*	*	*	*	*	*	*	*	Good
VeldhovenC.M.M.	*	*	*	*			*		*	Poor
Burke K.	*	*	*	*	*	*	*		*	Good
Ouchi K.	*	*	*	*			*	*	*	Poor
Liyanage T.	*	*	*	*			*	*	*	Poor
Mitchell G.K.	*	*	*	*			*		*	Poor
Ebke M.	*	*	*	*	*	*		*	*	Good
Mudge A.M.	*	*	*	*			*	*	*	Poor
Salat H.	*	*	*	*	*	*	*	*	*	Good
Malhotra R.	*	*	*	*				*	*	Poor
Hadique S.	*	*	*	*	*	*	*	*	*	Good
Gomez-BatisteX.	*	*	*	*	*	*	*	*	*	Good
Javier A.D.	*	*	*	*	*	*	*	*	*	Good
Amro O.W.	*	*	*	*	*	*	*	*	*	Good
Lakin J.R.	*	*	*	*	*	*	*		*	Good
Hamano J.		*	*	*	*	*		*	*	Good
Feyi K.	*	*	*	*	*	*		*	*	Good
Moroni M.	*	*	*	*	*	*	*	*	*	Good
O'Callaghan A.	*	*	*	*	*	*	*	*	*	Good
Da Silva GaneM.	*	*	*	*	*	*	*	*	*	Good
Pang W.-F.	*	*	*	*			*	*	*	Poor
Haga K.	*	*	*	*			*	*	*	Poor
Fenning S.	*	*	*	*	*	*	*	*		Good
Moss A.H.	*	*	*	*	*	*	*	*	*	Good
Cohen L.M.	*	*	*	*	*	*		*	*	Good
Moss A.H.	*	*	*	*	*	*		*	*	Good
Ros M.M.	*	*	*	*	*	*	*	*	*	Good
GuliniJ.E.H.M.B.	*	*	*	*	*	*	*	*	*	Good
Haydar S.A.	*	*	*	*	*	*	*			Poor
Carmen J.	*	*	*	*				*	*	Poor
Barnes S.	*	*	*	*	*	*	*			Poor
Straw S.	*	*	*	*	*	*	*	*	*	Good
Mahes A.	*	*	*	*	*	*	*	*	*	Good
Lin C.A.	*	*	*	*	*	*	*	*	*	Good
Um Y.W.	*	*		*	*	*	*	*	*	Good
Gaffney L.	*	*	*	*	*	*	*	*	*	Good

* denotes a study having met a particular quality item, scoring one point. The maximum points a study can score is nine, and the minimum is zero.