marginally significantp < 0.001
Co-occurrence was significantly higher than the baseline level regardless of sex (χ 2 = 13.78, p < 0.001 in boys; χ 2 = 45.44, p < 0.001 in girls), school locations (χ 2 = 50.70, p < 0.001 in urban schools; χ 2 = 3.29, p = 0.081 a marginally significant effect in rural schools), and grades (χ 2 = 18.34, p < 0.001 in Grade 4; χ 2 = 35.81, p < 0.001 in Grade 5).