Observational Study
Copyright ©The Author(s) 2015.
World J Psychiatr. Dec 22, 2015; 5(4): 425-431
Published online Dec 22, 2015. doi: 10.5498/wjp.v5.i4.425
Table 2 Bivariate analyses comparing grade average in the last trimester for boys only
VariableGrades 13 and above (above average grades)n = 377% (n) or mean (SD)Grades 12 and below (average and below average grades)n = 587% (n) or mean (SD)StatisticP value
Age17.2 (1.6)18.0 (1.6)t949 = -7.740.0005
n = 371n = 580
Days absent in the last 30 d
Not absent56.1% (211)39.4% (230)
1 d13.8% (52)17.6% (103)
2 d12.5% (47)12.7% (74)χ52 = 31.150.0005
3-4 d7.4% (28)11.3% (66)
5-6 d2.9% (11)5.7% (33)
7 or more days7.2% (27)13.4% (78)
n = 376n = 584
Father’s education level
Not educated19.5% (66)27.5% (142)
Elementary school16.3% (55)18.2% (94)
Middle school6.2% (21)11.8% (61)χ42 = 28.090.0005
High school21.6% (73)20.7% (107)
College and beyond36.4% (123)21.9% (113)
n = 338n = 517
Mother’s education level
Not educated36.3% (127)46.0% (251)
Elementary school14.3% (50)15.0% (82)
Middle school7.7% (27)9.0% (49)χ42 = 22.220.0005
High school16.9% (59)17.0% (93)
College and beyond24.9% (87)13.0% (71)
n = 350n = 546
Socioeconomic status compared with other families in country
Above other families26.1% (98)17.2% (101)
Same as other families68.5% (257)74.8% (439)χ22 = 12.400.002
Below other families5.3% (20)8.0% (47)
n = 375
Ever used alcohol, hashish, psychotropic, or other drugs33.7 (127)44.8 (263)χ2 = 11.780.001
Age first used alcohol, hashish, or psychotropic drugs15.0 (2.4)16.0 (2.0)t310 = -3.660.0005
n = 98n = 214
Used alcohol, hashish, or psychotropic drugs in the last 12 mo17.0 (64)23.3 (137)χ2 = 5.630.018
Used alcohol, hashish, or psychotropic drugs in the past 30 d10.9 (41)17.0 (100)χ2 = 6.980.008