Cost-utility analysis of melphalan plus prednisone with or without interferon-alpha 2b in newly diagnosed multiple myeloma. Results from a randomised controlled trial.

This study evaluated the cost utility of adding interferon-alpha 2b to conventional treatment in patients with multiple myeloma. It also provides a methodology for transforming complex quality-of-life profiles into a single index value on the conventional 0 to 1 quality-adjusted life-year scale (QALY). From 1990 to 1992, 583 patients with newly diagnosed, symptomatic multiple myeloma were enrolled in a randomised, multicentre, phase III study to evaluate the addition of interferon-alpha 2b to treatment with melphalan and prednisone. Addition of interferon-alpha 2b yielded a 12% increase in median survival time, at the expense of a slight reduction in quality of life during the first year of treatment. The gain in survival time was not large enough to reach statistical significance. Patients receiving interferon-alpha 2b also had a 5- to 6-month prolongation of the plateau phase. Cost per QALY gained by adding interferon-alpha 2b was conservatively estimated at $US110,000. Potentially better cost effectiveness may be found in different treatment regimens or in certain patient subgroups.