The systemic lupus erythematosus Tri-nation Study: absence of a link between health resource use and health outcome

OBJECTIVE: Health consumption and health status in SLE in three countries with different health funding structures were compared. METHODS: Seven hundred and fifteen SLE patients (Canada 231, USA 269, UK 215) were surveyed semi-annually over 4 yr for health resource utilization and health status. Cross-country comparisons of (i) cumulative health expenditure (calculated by applying 2002 Canadian prices to resources in all countries) and (ii) disease damage (Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index, SLICC/ACR DI) at study conclusion were performed after adjustment. Missing expenditure and damage data were managed through multiple imputation using best predictive regressions with all available data from all patients as potential covariates. RESULTS: Four hundred and eighty-five patients provided data at study entry and conclusion and at least four resource questionnaires (Canada 162, USA 157, UK 166); 41 died (Canada 13, USA 18, UK 10); 189 withdrew, were lost to follow-up or provided data at entry and conclusion but fewer than four resource questionnaires (Canada 56, USA 94, UK 39). At conclusion, after imputation, in Canada, the USA and the UK respectively, mean cumulative costs per patient over 4 yr [95% confidence interval (CI)] were $15,845 (13,509, 18,182), $20,244 (17,764, 22,724) and $17,647 (15,557, 19,737) and mean changes in SLICC/ACR DI were 0.49 (0.39, 0.60), 0.63 (0.52, 0.74) and 0.48 (0.39, 0.57). After adjustment for baseline differences, on average (95% CI), Canadian and British patients utilized 20% (8%, 32%) and 13% (1%, 24%) less resources than patients in the USA respectively, but experienced similar health outcomes. CONCLUSION: Despite patients in the USA incurring higher health expenditures, they did not experience superior health outcomes.