The costs and benefits were combined to estimate the cost per successfully treated patient. The cost per additional successfully treated patient using simvastatin was estimated incremental to using lovastatin/extended release niacin. The cost to achieve a successfully treated patient was:
in the population requiring an LDL of <160 mg/dL, $684 in the simvastatin group and $371 in the lovastatin/extended-release-niacin group;
in the population requiring an LDL of <130 mg/dL, $880 in the simvastatin group and $467 in the lovastatin/extended-release niacin group; and
in the population requiring an LDL of <100 mg/dL, $1,282 in the simvastatin group and $967 in the lovastatin/extended-release-niacin group.
For the <160 mg/dL goal, the incremental cost-effectiveness ratio for each additional patient to reach LDL and HDL goals without an adverse event with simvastatin was $4,427 when compared with lovastatin/extended-release niacin. Lovastatin/extended-release niacin had higher success rates and lower estimated costs than simvastatin for both the 130 and 100 mg/dL goal analyses, and thus dominated simvastatin.
The sensitivity analysis demonstrated that two variables impacted on the success rate of the <160 mg/dL goal model. These were the proportion of patients on simvastatin who reach LDL and HDL goals and the medical costs. Lowering the simvastatin effect by 25% resulted in the same success rate as the baseline lovastatin/extended-release niacin. When the medication costs were reduced by 25%, an incremental cost-effectiveness ratio of $2,733 was reported. For both the <130 and <100 mg/dL goal models, simvastatin was more successful than lovastatin/extended-release niacin when more than 86.8% and 76.6 % of patients, respectively, achieved HDL goals. Lovastatin/extended-release niacin remained the most successful strategy in the remaining sensitivity analysis.