“…Internal consistency by grouping constructs was reported by 19 studies ( Bowyer et al, 2014 , Reiter et al, 2009 , Dempsey et al, 2006 , Natan et al, 2011 , Reynolds and O'Connell, 2012 , Askelson et al, 2010a , Askelson et al, 2010b , Askelson et al, 2011a , Askelson et al, 2011b , Gainforth et al, 2012a , Gainforth et al, 2012b , Kahn et al, 2005 , Kahn et al, 2009 , Ogilvie et al, 2007 , Teitelman et al, 2011 , Fahy and Desmond, 2010 , Choi et al, 2013 , Marlow et al, 2009 , Thomas et al, 2013 ), of which ten studies ( Bowyer et al, 2014 , Reiter et al, 2009 , Dempsey et al, 2006 , Brawner et al, 2013 , Ogilvie et al, 2007 , Teitelman et al, 2011 , Fahy and Desmond, 2010 , Kahn et al, 2005 , Askelson et al, 2010a , Askelson et al, 2010b ) indicated lower internal consistency by some constructs (range: 20% to 65%). Lower explanatory power (< 70%) of theoretical models was identified within ten studies ( Bowyer et al, 2014 , Natan et al, 2011 , Askelson et al, 2010a , Askelson et al, 2011a , Askelson et al, 2011b , Teitelman et al, 2011 , Kahn et al, 2005 , Choi et al, 2013 , Marlow et al, 2009 , Thomas et al, 2013 ) (range: 10% to 68%). Higher explanatory power (≥ 70%) was reported in seven studies ( Reiter et al, 2009 , Reynolds and O'Connell, 2012 , Brawner et al, 2013 , Gainforth et al, 2012a , Teitelman et al, 2011 , Fahy and Desmond, 2010 , Askelson et al, 2010b ) (range: 70% to 96%).…”