Decreasing costs and improving outcomes in systemic lupus erythematosus: using regression trees to develop health policy.

OBJECTIVE

To characterize patients with systemic lupus erythematosus (SLE) who are expected to experience the highest direct and indirect monetary costs and greatest diminished productivity so that we may intervene to reduce costs and improve outcomes.

METHODS

We assessed demographics and health status in January, 1990 and costs incurred in the last 6 months of 1990 in January, 1991 in 151 patients with SLE enrolled in the Montreal General Hospital Lupus Registry. We used regression trees to separate low from high cost patients.

RESULTS

Patients with poor physical or poor psychological functioning incur the highest direct costs (3-fold and 1.6-fold the group mean, respectively); those with the poorest psychological functioning incur the highest indirect costs (2-fold the group average); and those with the most intense pain experience the greatest impairment in productivity (3-fold the group average).

CONCLUSION

Targeting patients with poor physical and psychological functioning and substantial pain with appropriate interventions may improve their outcomes and reduce disease costs. Targeting patients expected to have low costs with preventative interventions may delay worse outcomes and reduce future costs.