Table 3. Factors associated with out-of-control asthma.

By age group	Factor	Odds ratio (CI 95%)	P-value
5–11 years
Univariable	Obesitya	2.3 (1.1–4.7)	0.03
	Family incomeb<$50,000	1.5 (1.1,2.0)	0.007
Multivariable	Family income <$50,000	1.5 (1.1,2.0)	0.007
12–18 Years	No factors are significant
19+ Years
Univariable	Smokingc	2.3 (1.5,3.5)	<0.001
	Family income <$50,000	2.1 (1.5,3.0)	<0.001
	Race (Blacks)d	2.2 (1.03,4.8)	0.02
	Morbid obesity	1.5 (1.1,2.2)	0.008
	Less activitye	1.5 (1.1, 2.2)	0.01
	Gender (female)	1.6 (1.04,2.3)	0.02
Multivariable	Smoking	1.7 (1.1,2.7)	0.01
	Morbid obesity	1.7 (1.1,3.0)	0.02
	Family income <$50,000	1.6 (1.1,2.4)	0.01

Variables considered are as follows: age, gender, race, income, activity, flu vaccination, smoke exposure and obesity. Variables were fit singly (univariate modelling), and then a stepwise procedure examined all the variables together.

^aThe definition for obesity was appropriate to the age group considered and varied for those <19 and adults.^37,38 Non-obese was the reference group.

^bFamily income was self reported as total annual family income with reference group income of ⩾$50,000/year.

^cSmoking was self reported; current smoking status and nonsmoking was the reference group.

^dRace was self-reported race. White was the reference group.

^eActivity was self reported as the number of times per week with 15 min or more of moderate and 15 min or more of strenuous activity (examples given). Higher levels of activity, at least 15 min of moderate activity five or more times per week or 15 or more minutes of strenuous activity two or more times per week.