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