Table 2.

Risk of ADHD treatment discontinuation during total follow-up (N = 13,489)

Characteristics	Number	% Discontinued	Crude HR (95% CI)	Adjusted HR (95% CI)a
Time cohort
Jan 2002–Dec 2002	1,458	78.9	1.00 (reference)	1.00 (reference)
Jan 2003–June 2004	3,864	69.6	0.86 (0.81–0.91)	0.98 (0.92–1.04)
July 2004–Dec 2005	3,248	53.4	0.70 (0.66–0.75)	0.86 (0.81–0.92)
Sex
Male	5,907	60.3	1.00 (reference)	1.00 (reference)
Female	2,663	72.0	1.39 (1.32–1.45)	1.09 (1.04–1.15)
Age category
0–5 years	294	53.5	0.64 (0.57–0.72)	0.67 (0.59–0.75)
6–11 years	2,910	48.8	0.52 (0.49–0.56)	0.53 (0.50–0.56)
12–17 years	1,810	72.1	1.00 (reference)	1.00 (reference)
18–45 years	3,556	79.7	1.37 (1.29–1.45)	1.13 (1.06–1.19)

^aAdjusted for other characteristics in Table 2