Table 2.

Background characteristics of privately insured youth diagnosed with attention-deficit/hyperactivity disorder by stimulant use during the follow-up period

Characteristic	Patients with Stimulant Use % (n=89,031)	Patients without Stimulant Use % (n=82,095)	Statistics
Sex			Χ2=28.6, df=1, p<0.001
Male	67.68	66.47
Female	32.32	33.53
Age, years			Χ2=438.5, df=1, p<0.001
6–12	60.71	55.71
13–21	39.29	44.29
Any selected medicationa	6.00	6.42	Χ2=12.9, df=1, p=0.003
Selected diseasesa
Prothrombotic state	1.41	1.38	Χ2=0.4, df=1, p=0.51
Atherosclerosis	0.02	0.02	Χ2=0.2, df=1, p=0.68
Hyperlipidemia	0.28	0.31	Χ2=1.0, df=1, p=0.32
Collagen vascular disease	0.06	0.07	Χ2=1.0, df=1, p=0.32
Obesity	0.33	0.38	Χ2=4.1, df=1, p=0.04
Diabetes mellitus	0.28	036	Χ2=7.3, df=1, p=0.007
Asthma	3.44	3.69	Χ2=8.2, df=1, p=0.004
Renal disease	0.12	0.15	Χ2=4.0, df=1, p=0.05
Hypertension	0.12	0.13	Χ2=1.2, df=1, p=0.28
Depression	4.17	5.60	Χ2=189.4, df=1, p<0.0001
Anxiety	2.83	3.32	Χ2=34.7, df=1, p<0.0001
Substance use disorder	0.62	1.35	Χ2=237.1, df=1, p<0.0001
Any inpatient treatment	0.65	1.27	Χ2=178.5, df=1, p<0.0001

Note:

^aSelected medications and selected diseases are based on claims during the 180 day period before the index attention-deficit/hyperactivity disorder visit. Variables representing these medications, diseases, and inpatient treatment were entered into the propensity score. See Table 1 for list of the medications and diseases that were entered into the propensity score.