Prospective impact of socioeconomic status on acute exacerbations of chronic obstructive pulmonary disease requiring hospital-based care
| SES indicator | Risk of hospital-based care for COPD | |||
| Model 1 | Model 2 | Model 3 | Model 4 (mediation model) | |
| Race | ||||
| White | Referent | Referent | Referent | Referent |
| Black | 1.4 (1.04 to 1.9) | 1.2 (0.9 to 1.7) | 1.2 (0.9 to 1.6) | 1.2 (0.8 to 1.6) |
| Asian | 0.4 (0.1 to 1.2) | 0.5 (0.2 to 1.5) | 0.6 (0.2 to 1.9) | 0.5 (0.2 to 1.5) |
| Hispanic | 0.9 (0.6 to 1.4) | 0.8 (0.5 to 1.2) | 0.9 (0.5 to 1.3) | 1.0 (0.6 to 1.6) |
| Other | 1.5 (0.8 to 2.8) | 1.2 (0.6 to 2.3) | 1.2 (0.6 to 2.3) | 1.2 (0.6 to 2.2) |
| Education | ||||
| Less than high school | N/A | 1.9 (1.3 to 2.7) | 1.5 (1.01 to 2.1) | 1.1 (0.7 to 1.6) |
| Some college | N/A | 1.5 (1.1 to 2.1) | 1.2 (0.9 to 1.7) | 1.0 (0.7 to 1.4) |
| College degree or some graduate school | N/A | Referent | Referent | Referent |
| Income | ||||
| Low (<US$20 000) | N/A | 2.9 (1.8 to 4.5) | 2.1 (1.4 to 3.4) | 1.5 (0.9 to 2.4) |
| Medium (US$20 000–80 000) | N/A | 1.4 (0.96 to 2.0)* | 1.2 (0.9 to 1.8) | 1.0 (0.7 to 1.5) |
| High (>US$80 000) | N/A | Referent | Referent | Referent |
Hospital-based care=emergency department visit or hospitalisation for COPD from Kaiser Permanente Northern California computerised databases (see Methods).
Multivariable Cox proportional hazards analysis—all results are HRs 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); model 4=age, sex, race, educational attainment, household income, additional covariates (smoking history, occupational exposures on longest held job, body mass index and comorbidities) and COPD severity (COPD severity score and BODE score).
↵* p=0.084.
COPD, chronic obstructive pulmonary disease; SES, socioeconomic status.