Table 1.

QUADAS checklist for all included studies

Study	Representative patient population	Description selection criteria	Adequate reference standard	Adequate time between index and reference test	Reference standard applied in all patients	The same reference standard for all patients	Reference standard not part of index test	Description index & reference test	Blinding for reference standard	Blinding for index test	Same data available during evaluation as in clinical practice	Reporting of intermediate test results	Reporting of withdrawals
Arulampalam et al. (2001) [57]	Yes	Yes	Yes	Unclear	Yes	No	Unclear	Yes & unclear	Yes	No	Unclear	No	NA
Chen et al. (2007) [2]	Yes	Yes	Yes	Unclear	Yes	No	Unclear	Yes & unclear	Unclear	Unclear	Unclear	No	No
Cohade et al. (2003) [58]	Yes	Yes	Yes	Yes	Yes	No	Unclear	Yes & unclear	Yes	Unclear	No	Yes	No
Delbeke et al. (1997) [59]	Yes	Yes	Yes	Yes	Yes	No	No	Yes & yes	Yes	Yes	No	Unclear	No
Imbriaco et al. (2000) [6]	Yes	Yes	Yes	Yes	Yes	Yes	Unclear	Unclear	Yes	Unclear	Yes	Yes	No
Kim et al. (2005) [7]	Yes	Yes	Yes	Yes	Yes	No	Yes	Yes	Yes	Yes	Yes	Yes	No
Lonneux et al. (2002) [60]	Yes	Yes	Yes	Yes	Yes	Yes	No	Yes & partially	Yes	No	Yes	No	No
Nakamoto et al. (2007) [61]	Yes	Yes	Yes	Yes	Yes	No	No	Yes & unclear	Yes	Unclear	No	Yes	Yes
Ruhlmann et al. (1997) [62]	Yes	Yes	Yes	Unclear	Yes	No	Yes	Yes & unclear	Unclear	Unclear	Unclear	No	Yes
Schmidt et al. (2009) [63]	Yes	Yes	Yes	Yes	Yes	No	No	Yes	Yes	Unclear	No	Yes	NA
Staib et al. (2000) [64]	Yes	Yes	Yes	Yes	Yes	No	Unclear	Unclear	Yes	Unclear	Yes	No	NA
Valk et al. (1999) [65]	Yes	Yes	Yes	Yes	Yes	No	No	Unclear	Yes	Unclear	Unclear	Unclear	NA
Whiteford et al. (2000) [66]	Yes	Yes	Yes	Yes	Yes	No	Yes	Yes & unclear	Unclear	Unclear	Yes	Yes	Yes
Willkomm et al. (2000) [8]	Yes	Yes	Yes	Yes	Yes	No	Unclear	Unclear	Yes	Unclear	Yes	Unclear	Unclear

NA not applicable because there were no withdrawals