TABLE 2

Comparison of Participants and Nonparticipants in the Prospective Outcome Study Among Childhood ADHD Cases

Nonparticipants (N = 152)aParticipants (N = 232)P
Male, n (%)121 (79.6)167 (72.0)0.09
Age on 12/31/20090.39
 Mean (SD)30.2 (1.9)30.0 (1.9)
 Range27.0–34.027.0–33.9
White, n (%)150 (98.7)231 (99.6)0.57
Address at last study contact:
 Unknown, n17b00.06
 Within 250 miles of Rochester, n (%)112 (83.0)208 (89.7)
 >250 miles from Rochester, n (%)23 (17.0)24 (10.3)
Received stimulant treatment during childhood, n (%)119 (78.3)178 (76.7)0.72
Psychiatric diagnosis before age 18
 Unknown, nb17220.62
 No, n (%)58 (43.0)96 (45.7)
 Yes, n (%)77 (57.0)114 (54.3)
Substance abuse before age 18, n (%)33 (21.7)51 (22.0)0.95
Any learning disability before age 19, n (%)109 (71.7)161 (69.4)0.63
High school graduation statusc
 Unknown, n133<0.001
 Moved, n3132
 Graduated, n (%)70 (64.8)166 (84.3)
 GED, n (%)12 (11.1)9 (4.6)
 Dropped, n (%)26 (24.1)22 (11.2)
Sociodemographic factors at birth
 Maternal age at birth, mean (SD)25.7 (5.0)26.0 (4.6)0.44
 Maternal education
  Unknown, n15200.31
  <High school, n (%)16 (11.7)13 (6.1)
  High school graduate, n (%)52 (38.0)88 (41.5)
  Some college, n (%)44 (32.1)74 (34.9)
  College graduate, n (%)25 (18.3)37 (17.5)
 Maternal marital status
  Married, n (%)136 (89.5)212 (91.4)0.53
  Not married, n (%)16 (10.5)20 (8.6)
  • a Nonparticipants included ADHD cases who were either deceased (n = 7), incarcerated at the time of recruitment (n = 10), denied permission for use of records for research at the time of the prospective study (n = 17), or who declined participation or did not respond to the recruitment letters (n = 118).

  • b These subjects had previously denied access to their medical records for research purposes when these data were originally collected.

  • c The graduation status is the subject’s status as determined before their participation.