Drug treatments for maintaining remission in Crohn's disease. A lifetime cost-utility analysis.

A recent literature overview has estimated the long term frequency of the main outcomes of Crohn's disease (e.g. relapses, hospitalisations and surgery). Using these frequency data, we defined a model for the long term course of the disease. In this model, the quality-of-life (QOL) scores for the main levels of disease severity were determined by a panel of expert gastroenterologists. We conducted a combined analysis of these long term clinical data and of this QOL information to determine the cost-utility ratio of long term maintenance therapy with mesalazine (mesalamine) in patients with inactive Crohn's disease. After obtaining the cost-of-illness data needed for this analysis from a recent study conducted in the UK, we completed our incremental cost-utility analysis, in which mesalazine was compared with no maintenance treatment, using 2 hypothetical groups of 100 patients. These 2 groups were assumed to have the same general characteristics as those found in a group of 583 patients included in a recent meta-analysis. Our cost-utility evaluation included 5% annual discounting. In the mesalazine group, the overall lifetime costs for the 100 patients were around $US5 100,000 with an overall utility value of about 1700 quality-adjusted life years (QALYs). Both the lifetime costs and the utility values for the placebo (no treatment) group were very similar to those calculated for the mesalazine group. Our cost-utility analysis showed that mesalazine maintenance therapy was associated with a cost of about $US5000 per QALY gained. There was, therefore, a small incremental benefit obtained, albeit with a very small incremental cost. Sensitivity analyses confirmed these results. In conclusion, our study showed that long term maintenance therapy with mesalazine in patients with inactive Crohn's disease should not be discouraged on the basis of preliminary cost-utility considerations. However, long term placebo-controlled studies of mesalazine are urgently needed to better define the long term prognosis of these patients.