Table 4 Summary statistics for parametric comparison of composite z-scores for four cohorts of Irish/UK and North American DEP and GEP students

Cohort 1 SC1 (2008-2009)

0.69

2.07

2.29

3.45

<0.01

-2.84

125.69

0.47

Cohort 1 SC2 (2009-2010)

0.22

0.62

0.74

1.03

0.01

-2.60

119.20

0.44

Cohort 2 SC1 (2009-2010)

0.83

2.27

2.68

3.21

<0.01

-2.81

129.86

0.49

Cohort 2 SC2 (2010-20 11)

0.28

0.46

0.84

0.91

0.26

-1.13

126.65

0.20

Cohort 3 SC1 (2010-2011)

0.44

2.78

2.49

3.16

<0.01

-4.77

129.93

0.82

Cohort 3 5C2 (2011-2012)

0.08

0.62

0.77

0.92

<0.01

-3.66

128.94

0.64

Cohort 4 SC1 (2011-2012)

0.82

2.51

2.58

3.33

<0.01

-3,43

142.40

0.57

Cohort 4 SC2 (2012-2013)

0.25

0.61

0.69

0.88

<0.01

-2.73

138.56

0.45