Table 3

Risk of bias measured by the Newcastle-Ottawa Scale

Study lead authorStudy yearSelectionComparabilityOutcomeOverall score
(number of stars)
Rosengren et al 29 2009******6
Tedrow et al 24 2010******6
Grundvold et al 23 2012******6
Huxley et al 30 2014*******7
Alonso et al 21 2015******6
Diouf et al 27 2015*****5
Grundvold et al 22 2015******6
Johnson et al 25 2015*******7
Berkovitch et al 28 2016*******7
Ball et al 26 2018******6

  • Scores range from 0 to 9 stars with nine stars equating to the lowest risk of bias.