In many diseases,those with a low socioeconomic status (SES) as measured by income, education or other parameters, is associated with worse health outcomes. The Canadian 1000 Faces of Lupus group has shown that this is the case in SLE, where there is more disease activity with lower levels of education. Similarly, the Canadian Early Arthritis Cohort (CATCH) study showed that new RA patients with low SES presented with slightly worse disease activity but responded equally to treatment. The Canadian Scleroderma Research Group (CSRG) found that SES as measured by education did not have much effect on SSc outcome, but these patients had consented to being in the database and were literate. There may have been a bias against enrolling patients in the lowest SES as they may not have wanted to (or been able to) complete regular questionnaires.
The University Health Network at the University of Toronto (from Dr. John Granton and Dr. Sindhu Johnson's group) has shown that in pulmonary arterial hypertension (PAH) from connective tissue disease and also idiopathic PAH, there was reduced survival in those with low SES (abstract #1874). The survival in middle and high SES did not look different. Six hundred patients with PAH (¾ had CTD) were followed and ⅓ died. What is not known is why there is increased mortality in the low SES group. There was not a dose response since high and middle SES groups looked similar. Is it other poor health-related behaviours? Or a delay in therapy (PAH drugs are very expensive), or later presentation, poor adherence, etc? The reasons for this were not addressed.
We likely should be collecting SES data on our patients and also in research as low SES is associated with worse outcomes in many rheumatic diseases. Health equity can only be achieved if we understand what accounts for worse outcomes in the low SES group.
Dr. Janet Pope is Professor of Medicine at Western University and Division Head of Rheumatology. Dr. Pope's research interests include epidemiologic studies in scleroderma, classification criteria in systemic sclerosis, systemic lupus erythematosus and rheumatoid arthritis.View Full Bio