Table 2

Socioeconomic status, race–ethnicity and chronic obstructive pulmonary disease severity

SES indicatorCOPD severity scoreBODE score
Model 1Model 2Model 3Model 1Model 2Model 3
Race
 WhiteReferentReferentReferentReferentReferentReferent
 Black1.5 (0.5 to 2.4)1.0 (0.04 to 1.9)0.7 (−0.2 to 1.6)0.4 (0.03 to 0.8)0.1 (−0.2 to 0.5)0.07 (−0.3 to 0.4)
 Asian−1.5 (−3.5 to 0.6)−0.5 (−2.5 to 1.5)−0.5 (−2.5 to 1.5)−0.2 (−1.1 to 0.6)0.3 (−0.5 to 1.1)0.5 (−0.3 to 1.2)
 Hispanic−0.5 (−1.7 to 0.7)−0.9 (−2.1 to 0.2)−1.1 (−2.2 to 0.1)−0.1 (−0.6 to 0.4)−0.3 (−0.8 to 0.1)−0.3 (−0.8 to 0.1)
 Other0.4 (−1.6 to 2.3)−0.2 (−2.1 to 1.6)−0.4 −2.3 to 1.4)0.4 (−0.3 to 1.2)0.08 (−0.6 to 0.8)0.06 (−0.7 to 0.8)
Education
 Less than high schoolN/A2.0 (1.0 to 2.9)1.8 (0.9 to 2.7)N/A1.1 (0.7 to 1.4)1.0 (0.6 to 1.3)
 Some collegeN/A1.4 (0.6 to 2.3)1.3 (0.4 to 2.0)N/A0.7 (0.4 to 1.0)0.6 (0.3 to 1.0)
 College degree+N/AReferentReferentN/AReferentReferent
Income
 LowN/A3.6 (2.3 to 4.9)3.4 (2.1 to 4.7)N/A1.9 (1.4 to 2.4)1.7 (1.2 to 2.2)
 MediumN/A1.4 (0.5 to 2.3)1.4 (0.5 to 2.2)N/A0.8 (0.4 to 1.1)0.7 (0.4 to 1.0)
 HighN/AReferentReferentN/AReferentReferent
  • Educational attainment categories are less than high school, some college, college degree or graduate school; income categories are low (<US$20 000), medium (US$20 000–80 000), high (>US$80 000) and missing.

  • Higher COPD severity scores and BODE scores=poorer status.

  • Multivariable linear regression analysis—all results are mean difference compared to referent group (95% CIs).

  • Model 1=impact of race, adjusting for age and sex; model 2=impact of race, educational attainment and household income, adjusting for age and sex; model 3=race, educational attainment and household income, adjusting for age and sex; also including additional covariates (smoking history, occupational exposures on longest held job, body mass index and comorbidities—see Methods).

  • COPD, chronic obstructive pulmonary disease; N/A, not applicable; SES, socioeconomic status.