Table 4.

Dose-Response Relationship in the Association Between Stimulant Treatment and an Adverse Cardiovascular Event in Children with ADHD

	Adjusted hazard ratioa	95% confidence interval
Stimulant dosage at the time of the adverse cardiovascular event (n=8300)
Non-user (reference)	1
Dosage <15 mg methylphenidate	2.31	1.18	4.53
Dosage 15–30 mg methylphenidate	1.28	0.65	2.53
Dosage >30 mg methylphenidate	1.08	0.54	2.14
Stimulant dosage 3 months before the adverse cardiovascular event (n=8298)
Non-user (reference)	1
Dosage <15 mg methylphenidate	2.04	1.01	4.12
Dosage 15–30 mg methylphenidate	1.42	0.74	2.73
Dosage >30 mg methylphenidate	0.82	0.37	1.81
Stimulant dosage 12 months before the adverse cardiovascular event (n=8295)
Non-user (reference)	1
Dosage <15 mg methylphenidate	1.43	0.57	3.59
Dosage 15–30 mg methylphenidate	1.67	0.84	3.32
Dosage >30 mg methylphenidate	2.24	1.20	4.21

Bold indicates a significantly increased hazard ratio compared to the reference group.

^aHazard ratios were adjusted for all covariates mentioned in Table 3.

ADHD, attention-deficit/hyperactivity disorder.