TABLE 2.

Unadjusted and Adjusted Estimates of Noncoverage Bias for Selected Measures of Health-Related Behaviors, Health Status, and Health Care Service Use, by Age and Household Poverty Status: United States, 2007

	Young Adultsa (n = 4544)			Low-Income Personsb (n = 6591)
Measure	Population Estimate, % (SE)	Unadjusted Bias, Percentage Points (SE)	Adjusted Bias, Percentage Points (SE)	Population Estimate, % (SE)	Unadjusted Bias, Percentage Points (SE)	Adjusted Bias, Percentage Points (SE)
Health-related behaviors
≥ 5 or more alcoholic drinks in 1 d at least once in past y	34.5 (1.20)	−6.4 (1.00)*	−5.9 (0.99)*	18.8 (0.79)	−4.9 (0.64)*	−3.3 (0.58)*
Current smoker	24.5 (1.00)	−2.5 (0.79)*	−2.5 (0.80)*	26.6 (0.74)	−2.4 (0.49)*	−1.8 (0.45)*
Engaged in regular leisure-time physical activity	36.0 (1.08)	−2.2 (0.86)*	−1.7 (0.86)	22.2 (0.75)	−2.4 (0.54)*	−0.9 (0.47)
Health status
Health status described as excellent or very good	75.5 (0.90)	−0.6 (0.66)	−0.1 (0.67)	45.3 (0.88)	−4.4 (0.62)*	−1.3 (0.57)*
Experienced serious psychological distress in past 30 d	2.3 (0.29)	−0.2 (0.21)	−0.2 (0.22)	6.1 (0.37)	−0.4 (0.24)	−0.6 (0.24)*
Obese (adults aged ≥ 20 y)	20.0 (0.82)	0.6 (0.59)	0.4 (0.60)	30.5 (0.79)	1.4 (0.50)*	0.8 (0.48)
Asthma episode in past 12 mo	4.0 (0.39)	−0.2 (0.30)	−0.2 (0.30)	5.3 (0.36)	0.3 (0.20)	0.3 (0.16)*
Ever diagnosed with diabetes	1.1 (0.29)	0.0 (0.18)	0.0 (0.17)	10.1 (0.50)	1.9 (0.26)*	0.5 (0.26)
Health care service use
Has usual place to go for medical care	69.8 (0.98)	4.0 (0.75)*	4.3 (0.76)*	74.8 (0.79)	3.7 (0.53)*	2.0 (0.47)*
Received influenza vaccine during past 12 mo	13.9 (0.68)	0.0 (0.51)	2.2 (0.46)*	24.8 (0.73)	3.2 (0.45)*	1.9 (0.47)*
Ever been tested for HIV	40.9 (1.00)	−1.9 (0.75)*	−2.2 (0.75)*	41.8 (0.84)	−2.8 (0.54)*	−1.5 (0.50)*
Failed to obtain needed medical care in past 12 mo because of financial barriers	9.5 (0.56)	−1.9 (0.42)*	−2.0 (0.43)*	15.6 (0.59)	−1.5 (0.38)*	−1.6 (0.36)*
Currently uninsured	29.1 (0.95)	−2.2 (0.74)*	−2.9 (0.76)*	32.8 (0.88)	−3.4 (0.57)*	−1.7 (0.54)*

Note. The population estimate was for all adults within the age or income group with nonmissing data for household telephone status. Unadjusted bias was calculated as the estimated value for adults living in landline telephone households minus the population estimate. Both values were weighted estimates from the 2007 National Health Interview Survey. To calculate the adjusted bias, the estimated value for adults living in landline telephone households was recalculated (as a predictive margin for logistic regression) to correct for group differences with the full population on measures of race/ethnicity, gender, and education, as well as age (for low-income adults). For both samples, sample sizes were unweighted.

Source. Centers for Disease Control and Prevention, National Center for Health Statistics, National Health Interview Survey, 2007.⁷

^aAged 18 to 29 years.

^bHousehold income below 200% of the federal poverty level.

*P ≤ .05 (value significantly different from 0).