Economic evaluation in gastrointestinal disease

Safety and efficacy are not the only parameters of interest in the choice of medical technology--costs are playing an increasingly important role. There is growing interest in 'value for money', which can be assessed economically by comparing the costs and consequences of alternative courses of action. A number of different economic evaluation methods may be used: cost-minimization (only costs examined with no consideration given to consequences); cost-effectiveness (in which a unidimensional clinical outcome is assessed, for example, life-years gained); cost-utility (multidimensional outcomes measured, for example quantity and quality of life); and cost-benefit (where outcome is considered in monetary terms). Ulcer disease offers several examples of how economic evaluation can be used to address issues related to efficiency and value for money in healthcare. In a study of reflux oesophagitis, omeprazole was shown to be more cost-effective than ranitidine in a 12-week treatment study. With omeprazole the costs were lower and the effectiveness better than with the H2-receptor antagonist. In a later study the cost-effectiveness of omeprazole and ranitidine are compared for both intermittent and maintenance treatment in reflux oesophagitis. Using a Markov chain approach, Swedish cost data and studying a time period of 12 months, it found that omeprazole is both more effective in providing healthy days and less costly than ranitidine for both treatment strategies. The comparison between intermittent treatment and maintenance treatment with omeprazole shows that the latter is more effective but also more costly. It is concluded that the relative cost-effectiveness of omeprazole maintenance treatment increases with the risk of relapse when off treatment, the severity of symptoms following relapse, and the value of healthy days, i.e. days free from reflux oesophagitis. A model analysis comparing Helicobacter pylori eradication with conventional treatments in patients with duodenal ulcer disease has shown H. pylori eradication to be cost-effective when compared with either episodic therapy using omeprazole or maintenance therapy with ranitidine. The study used a Markov chain approach, and included the cost of treatment, in Swedish crowns, in a Swedish primary care setting over a period of 5 years. In the analysis, patients receiving conventional therapy were initially healed with omeprazole, 20-40 mg once daily. Following healing patients were either treated with further courses of omeprazole upon relapse or were given maintenance treatment with ranitidine, 150 mg once daily. The patients who were assigned to the H. pylori eradication therapy group were initially given an H. pylori test. Those patients who proved positive for the bacterium received omeprazole, 20 mg twice daily, plus amoxicillin, 2000 mg daily in divided doses, for 2 weeks, followed by omeprazole, 20 mg once daily, for a further 2 weeks to ensure healing. Patients who were H. pylori-negative were assigned to receive either episodic or maintenance therapy as described above. The model assumption applied in the H. pylori eradication group was that, following successful healing and H. pylori eradication, virtually all patients were cured and experienced no relapse during the following 5 years. by contrast, almost all the patients assigned to episodic therapy relapsed, and during maintenance therapy with H2-receptor antagonists, most patients experienced at least one relapse. Although H. pylori eradication resulted in initial higher costs than the alternative strategies, it reduced the risk of recurrence and for most patients there were no future costs. The investment therefore paid off within a relatively short period of time. Even when unfavourable assumptions were made, such as an H. pylori eradication rate of only 50%, the H. pylori eradication strategy had a pay-off period of less than 1.3 years compared with maintenance treatment, and 3 years compared with episodic