Dorien Bangma

188 | CHAPTER 8 Table 8.1. Demographic characteristics of total sample and ADHD groups. Total sample ADHD Adult-only ADHD Subthreshold ADHD No ADHD Group differences Statistics p d N 1292 46 57 162 265 - Age M (SD) 48.8 (18.5) 31.5 (12.5) 36.7 (16.9) 38.1 (17.2) 37.1 (16.2) F(3 ,529) = 2.0 .110 0.213 Age range 18 - 93 18 - 69 18 - 84 18 - 90 18 - 93 - Sex % male / % female 45.4/54.6 60.9/39.1 40.4/59.6 45.7/54.3 45.7/54.3 X 2 (3) = 4.8 .187 0.191 Level of education 1,2 - - - - - X 2 (6) = 3.1 .792 0.155 Lower % 9.1 4.3 10.5 6.2 6.5 X 2 (3) = 1.9 .604 0.118 Intermediate % 27.9 30.4 19.3 24.7 24.3 X 2 (3) = 1.7 .633 0.114 Higher % 63.0 65.2 70.2 69.1 69.2 X 2 (3) = 0.4 .950 0.052 Employment status - - - - - X 2 (15) = 26.4 .035* 0.458 Student % 14.7 30.4 40.4 33.3 24.9 X 2 (3) = 7.1 .070 0.232 Employed (part-time) % 20.8 17.4 10.5 a 17.3 24.9 X 2 (3) = 8.0 .047* 0.248 Employed (full-time) % 32.2 34.8 26.3 30.2 36.6 X 2 (3) = 3.3 .351 0.159 Unemployed % 4.7 6.5 12.3 a 6.2 3.0 X 2 (3) = 8.7 .034* 0.258 In retirement % 23.1 2.2 7.0 7.4 7.2 X 2 (3) = 1.7 .635 0.114 Other % 4.5 8.7 3.5 5.6 3.4 X 2 (3) = 3.2 .367 0.155 Note. ADHD = attention-deficit/hyperactivity disorder; ARS = attention-deficit/hyperactivity disorder rating scale. 1 Levels of education are based on the Verhage coding system (Verhage, 1964) which ranges from 1 (primary school not finished) to 7 (university degree). Verhage classification 1 – 4 are equivalent to lower education, 5 is equivalent to intermediate education and 6 and 7 are equivalent to higher education. 2 Missing data: n = 4 in Total sample and n = 2 in No ADHD group. * p < .05. Post-hoc Bonferroni significant group differences: a versus No ADHD group.