The association between obstructive sleep apnea and metabolic syndrome: a systematic review and meta-analysis

BMC Pulmonary Medicine

Table 2 Scores of Newcastle-Ottawa quality assessment scale

Studies	Selection				Comparability		Exposure			Total scale
	1	2	3	4	5A	5B	6	7	8	Total scale
Cross-sectional study
Jamie C.M. Lam, 2006 [35]	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	9
James M. Parish, 2007 [28]	Yes	Yes	No	Yes	No	No	Yes	Yes	No	5
Susan Redline, 2007 [43]	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	9
F. Javier Nieto, 2009 [26]	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	No	8
Francesco Angelico, 2010 [31]	Yes	Yes	No	Yes	No	No	Yes	Yes	Yes	6
Stephen Guill, 2010 [42]	Yes	No	Yes	Yes	No	No	Yes	Yes	Yes	6
Nikolaos Papanas, 2010 [18]	Yes	Yes	No	Yes	No	No	Yes	Yes	Yes	6
Swastik Agrawal, 2011 [30]	Yes	Yes	No	Yes	No	No	Yes	Yes	Yes	6
H.-W.M. Breuer, 2011 [40]	Yes	Yes	No	Yes	No	No	Yes	Yes	Yes	6
M. Gasa, 2011 [32]	Yes	Yes	No	Yes	Yes	Yes	Yes	Yes	Yes	8
Duygu Ozol, 2011 [29]	Yes	Yes	No	Yes	No	No	Yes	Yes	Yes	6
Jenny Theorell-Haglöw, 2011 [27]	Yes	Yes	Yes	Yes	No	No	Yes	Yes	Yes	7
Assoumou HG, 2012 [36]	Yes	Yes	Yes	Yes	No	No	Yes	Yes	Yes	7
Qi-Chang Lin, 2012 [33]	Yes	Yes	No	Yes	No	No	Yes	Yes	Yes	6
Bienvenido Barreiro, 2013 [37]	Yes	No	No	Yes	No	No	Yes	Yes	Yes	5
Case–control study
Steven R. Coughlin, 2004 [17]	Yes	No	No	Yes	Yes	Yes	Yes	Yes	Yes	7
Ryujiro Sasanabe, 2006 [39]	Yes	Yes	No	Yes	Yes	Yes	Yes	Yes	Yes	8
Bharat Bhushan, 2010 [34]	Yes	No	No	Yes	Yes	Yes	Yes	Yes	Yes	8
Ozen K. Basoglu, 2011 [38]	Yes	Yes	No	Yes	No	No	Yes	Yes	Yes	6
A. Barcelo, 2011 [41]	Yes	No	No	Yes	No	No	Yes	Yes	Yes	5

A star rating system was used to indicate the quality of a study, with a maximum of nine stars. A study could be awarded a maximum of one star for each numbered item within the selection and exposure categories. A maximum of two stars could be allocated for comparability

ISSN: 1471-2466