Cost of lipid lowering in patients with coronary artery disease by case method learning.

OBJECTIVES

This investigation was undertaken to study the costs of a Case Method Learning (CML)-supported lipid-lowering strategy in secondary prevention of coronary artery disease (CAD) in primary care.

METHODS

This prospective randomized controlled trial in primary care with an additional external specialist control group in Södertälje, Stockholm County, Sweden, included 255 consecutive patients with CAD. Guidelines were mailed to all general practitioners (GPs; n=54) and presented at a common lecture. GPs who were randomized to the intervention group participated in recurrent CML dialogues at their primary health-care centers during a 2-year period. A locally well-known cardiologist served as a facilitator. Assessment of low-density lipoprotein (LDL) cholesterol was performed at baseline and after 2 years. Analysis according to intention-to-treat-intervention and control groups (n=88)--was based on group affiliation at baseline. The marginal cost of lipid lowering comprised increased cost of lipid-lowering drugs in the intervention group compared with the primary care control group, cost of attendance of the GP's in the intervention group, and cost of time for preparation, travel, and seminars of the facilitator. Costs are as of 2002 with an exchange rate 1 U.S. dollar = 9.5 SEK (Swedish Crowns).

RESULTS

Patients in the primary care intervention group had their LDL cholesterol reduced by 0.5 (confidence interval [CI], 0.1-0.9) mmol/L compared with the primary care control group (p < .05). No change occurred in controls. LDL cholesterol in the external specialist control group decreased by 0.6 (CI, 0.4-0.8) mmol/L. The cost of the educational intervention represented only 2 percent of the drug cost. The cost of lipid lowering in the intervention group, including the cost of the educational intervention, was actually lower than that of patients treated at the specialist clinic--106 U.S. dollar per mmol decrease in LDL cholesterol in the intervention group and 153 U.S. dollar per mmol decrease in LDL cholesterol in the specialist group. EuroQol 5D Index, which gives an estimate of global health-related quality of life, was 0.80 (CI, 0.75-0.85) in the present cohort.

CONCLUSIONS

The additional cost of CML was only 2 percent of the drug cost. Assuming the same gain in life expectancy per millimole decrease in LDL cholesterol as in the 4S-study gives a cost per gained quality-adjusted life year of U.S. dollar 24,000. This finding indicates that the CML-supported lipid-lowering strategy is cost-effective. The low cost of CML in primary care should probably warrant its use in the improvement of the quality of care in other major chronic diseases.