The results need to be interpreted in light of the limitations of the model. The small sample size and the missing values of resource use did not allow estimation of costs of the six health states individually. learn more Instead the three health-states costs were estimated and the ethyl-EPA drug cost (£24) was added for the three health states of the treatment group. The health-state costs for the placebo and the treatment group may differ due to different resource use and adverse effects of the treatment. Different transitional probabilities for the patients receiving placebo and the patients receiving ethyl-EPA can capture this effect to a certain degree
as different numbers of patients have manic and Inhibitors,research,lifescience,medical depressive episodes and consequently different level of resource use. Assigning different utility values for inpatient and outpatient acute episodes and additional health states to reflect the severity of episodes can complicate the model but it can capture the complex nature of the disease. However, it is not possible with the Inhibitors,research,lifescience,medical limited data available. The model also assumes that the probability of an event is independent of the previous episode and constant Inhibitors,research,lifescience,medical over time. However, in
reality a mood episode might be influenced by the previous episode or hospital admission. Soares-Weiser and colleagues showed that patients’ most recent episode is related to the type of their next episode [Soares-Weiser et al. 2007]; the treatments aimed at preventing depression may be more cost-effective in patients with a recent history of depression compared with Inhibitors,research,lifescience,medical patients with a recent history of mania and vice versa for treatments aimed at preventing manic episode. In the 1-year model developed in this paper the average number of acute episodes per patient is less than one per patient therefore it is unlikely to have a substantial effect on the results. Given the chronic nature of BD and the relatively early age of onset [Soares-Weiser et al. 2007], a 1-year time
horizon could be considered too short to capture the lifetime costs and benefits of the treatment. Inhibitors,research,lifescience,medical A longer time period model is needed to reflect the actual course of BD and lifetime costs and benefits. Economic models frequently make extrapolations Histamine H2 receptor from short trials to longer time periods. Here we have made extrapolations to 1-year on the basis of data collected from a 12-week trial. In subsequent analyses we also extended the model to five years and clearly this is a limitation implying that we need to be cautious about the results from the extended model. In addition, adherence to the same treatment is expected to be low after an acute episode therefore the assumption of the same treatment has its own limitations. The cost perspective also needs to be broadened to include wider societal costs of BD. Conclusion The economic model estimated cost-effectiveness of ethyl-EPA as an adjunct treatment for BD patients over the time period of 1 year.