Previous studies have shown that, compared with ranitidine, omeprazole is a cost-effective treatment for acid-related disease. However, since more evidence is continually emerging and since prices vary, both across countries and with the passage of time, re-evaluation is necessary. Furthermore, it is important to critically review various methodological aspects. Using the Markov chain approach, this paper analyses the relative cost-effectiveness of omeprazole and ranitidine in the intermittent treatment of duodenal ulcer in Great Britain. The importance for the result of inclusion and exclusion of relapses and the length of the time-period studied are also investigated. While both factors are important, the effect of including relapses in the analysis is more important than the effect of extending the time-period. It is found that the treatment alternative with omeprazole is relatively more cost-effective when relapses are excluded compared with when relapses are included. We conclude that, while the time-period studied should always be extended as much as data allow, the inclusion of relapses seems to be of more crucial importance and is therefore strongly recommended.
With regard to the comparison between the 2 strategies, the analysis shows, firstly, that the omeprazole strategy is more effective than the ranitidine strategy in providing healthy days (i.e. ulcer-free days). When relapses are included and when a period of 5 years is considered, the difference ranges between 32 and 53 days, depending on the relapse rate. Secondly, the omeprazole strategy is less costly when both direct and indirect costs are considered. Hence, it is concluded that, in Great Britain, the omeprazole strategy is a superior treatment alternative to ranitidine, with a lower cost and a better effect.