Is systemic lupus erythematosus different in urban versus rural living environment? Data from the Cretan Lupus Epidemiology and Surveillance Registry.

BACKGROUND: Examining urban-rural differences can provide insights into susceptibility or modifying factors of complex diseases, yet limited data exist on systemic lupus erythematosus (SLE). OBJECTIVE: To study SLE risk, manifestations and severity in relation to urban versus rural residence. METHODOLOGY: Cross-sectional analysis of the Crete Lupus Registry. Demographics, residency history and clinical data were obtained from interviews and medical records ( N=399 patients). Patients with exclusively urban, rural or mixed urban/rural residence up to enrolment were compared. RESULTS: The risk of SLE in urban versus rural areas was 2.08 (95% confidence interval: 1.66-2.61). Compared with rural, urban residence was associated with earlier (by almost seven years) disease diagnosis - despite comparable diagnostic delay - and lower female predominance (6.8:1 versus 15:1). Rural patients had fewer years of education and lower employment rates. Smoking was more frequent among urban, whereas pesticide use was increased among rural patients. A pattern of malar rash, photosensitivity, oral ulcers and arthritis was more prevalent in rural patients. Residence was not associated with organ damage although moderate/severe disease occurred more frequently among rural-living patients (multivariable adjusted odds ratio: 2.17, p=0.011). CONCLUSION: Our data suggest that the living environment may influence the risk, gender bias and phenotype of SLE, not fully accounted for by sociodemographic factors.

Clinical and financial burden of active lupus in Greece: a nationwide study.

Analyses of the medical and economic burden of chronic disorders such as systemic lupus erythematosus (SLE) are valuable for clinical and health policy decisions. We performed a chart-based review of 215 adult SLE patients with active autoantibody-positive disease at the predefined ratio of 30% severe (involvement of major organs requiring treatment) and 70% non-severe, followed at seven hospital centres in Greece. We reviewed 318 patients consecutively registered over three months (sub-study). Disease activity, organ damage, flares and healthcare resource utilization were recorded. Costs were assessed from the third-party payer perspective. Severe SLE patients had chronic active disease more frequently (22.4% vs 4.7%), higher average SLE disease activity index (SLEDAI) (10.5 vs 6.1) and systemic lupus international collaborating clinics (SLICC) damage index (1.1 vs 0.6) than non-severe patients. The mean annual direct medical cost was €3741 for severe vs €1225 for non-severe patients. Severe flares, active renal disease and organ damage were independent cost predictors. In the sub-study, 19% of unselected patients were classified as severe SLE, and 30% of them had chronic active disease. In conclusion, this is the first study to demonstrate the significant clinical and financial burden of Greek SLE patients with active major organ disease. Among them, 30% display chronic activity, in spite of standard care, which represents a significant unmet medical need.