The Association of Socioeconomic Status with Outcomes in Cystic Fibrosis Patients in the United States

There is considerable variability in the clinical course of disease in cystic fibrosis (CF). Although currently unidentified modifier genes might explain some of this heterogeneity, other factors are probably contributory. Socioeconomic status (SES) is an important predictor of health status in many chronic polygenic diseases, but its role in CF has not been systematically evaluated. We performed a historical cohort analysis of pediatric CF patients in the United States using National Cystic Fibrosis Foundation Patient Registry (NCFPR) data for 1986 to 1994, and used Medicaid status as a proxy for low SES. The adjusted risk of death was 3.65 times higher (95% confidence interval [CI]: 3.03 to 4.40) for Medicaid patients than for those not receiving Medicaid. The percent predicted FEV1 of surviving Medicaid patients was less by 9.1% (95% CI: 6.9 to 11.2). Medicaid patients were 2.19 times more likely to be below the 5th percentile for weight (95% CI: 1.91 to 2.51) and 2.22 times more likely to be below the...