Table 3

Newcastle-Ottawa Scale for included studies

First author, yearSelectionComparabilityOutcomeTotal score
Representativeness of the cohortSelection of the non-exposed cohortAscertainment of exposureOutcome of interest not present at start of the studyOf cohorts based on design or analysis
(max: ++)		Assessment of outcomeFollow-up, long enoughAdequacy of follow-up of cohorts
Aurore et al,16 2011++++−+++7
Bougouin et al,29 2014+++++++++9
Bro-Jeppesen, et al,17 2012++++−++−6
Callaway et al,7 2014+++++++++9
Casella et al,28 2015−−+++++−6
Dankiewicz et al,18 2015−++++++++8
Geri et al,19 2015++++−+++7
Hollenbeck et al,20 2014−+++++++7
Kleissner et al,21 2015−+++−+++6
Mooney et al,5 2011++++−+++7
Nanjayya and Nayyar 2012−+++−+++6
Nielsen et al,23 2009−+++−+++6
Strote et al,24 2012−+++−++−5
Tømte et al,25 2011+−++−+++6
Vyas et al,6 2014+++++++++9
Weiser et al,26 2013−++++++−6
Zanuttini et al,27 2012++++−+++7