The relationship between Socioeconomic Status (SES) and Clinical outcomes among Cystic Fibrosis Patients in Belgium.

Background: Studies have revealed the impact of socioeconomic status (SES) on the severity of many diseases. This study investigated links between socioeconomic factors and clinical outcomes amongst Belgian cystic fibrosis (CF) patients.
Methods: In a cross-sectional study, patients with CF visiting Belgian accredited CF centers were eligible. Socioeconomic data was collected via questionnaire while clinical outcomes were extracted from the patient registry.
Results: 294 out of 402 enrolled patients participated. Mean (SD) age was 20.8(12.0) years with 52.0% as adults. 85.0% were from households with <2000 EURO pm equivalent. No income difference was noted across gender or with the general population. The average monthly bill on health expenses by households with a CF patient was 327 EURO (national mean = 125 EURO). 52.7% (32.6%) of those from households using less (more) than 125 EURO pm on health had chronic Pseudomonas aeruginosa infection but after correcting for age and gender the difference was not significant. Those who spent less also had significantly worse lung function; the mean (SD) % of predicted FEV1 was 65.1(25.3) % compared to 76.7(23.8) % respectively. After correcting for gender and age, FEV1 was inversely associated with household income and only marginally associated with amount spent on health.
Conclusion: The amount actually spent on the healthcare was associated with more clinical outcomes compared to the household income, making it a potential SES indicator in this population. However, the direction of the association is unexpected. Unfortunately the relationship between the reported expenditure and exact healthcare costs is not known. Belgium has a universal medical insurance system. However differential reimbursements, exemptions and third party payments (public insurance and patient's association) advantage those with less income or with disabilities. These multiple sources of financial assistance make the reported health expenditures less reliable and may reduce the disparities occasioned by differences in socioeconomic factors.