Page 77 - ADD-ON ABLATION SURGERY IN PATIENTS WITH ATRIAL FIBRILLATION

options is divided by the gain in QoL.The result of this calculation was defined as the incremental costs per QALY. Furthermore, to test the robustness of the cost analysis and to obtain uncertainty intervals (UIs) around the mean difference of the costs and the QALYs, the bootstrap method was used (1000 replications), based on random sampling with replacement based on original individual data of the participants through a large number of simulations39.To account for the uncertainty surrounding the ICERs, a bootstrap analysis was also performed. The Dutch Council for Public Health and Health Care argues that thresholds can vary from €16,000 to a maximum of € 80,000 for a condition with a high disease burden40. Hence, based on this information, assuming a threshold value of €60,000 for the treatment of AF seems acceptable.
Total costs of the add-on ablation surgery group were significantly higher compared to the regular cardiac surgery group (cost difference bootstrap: €4,724; 95% uncertainty interval (UI), €2,770–€6,678).The bootstrapped difference in QALYs was not statistically significant (0.06; 95% UI: –0.024 to 0.14). The incremental cost-effectiveness ratio is €73,359 per QALY. The acceptability curve showed that, even in the case of a maximum threshold value of €80,000 per QALY gained, the probability of add-on surgery being more cost-effective than regular cardiac surgery did not reach beyond 50%. Hence, based on the data of a 1-year follow- up,AS cannot be considered a cost-effective treatment.
Apart from the employment of a microwave energy source the short follow-up is a limitation of our study. Indeed, it seems reasonable to suppose that longer follow-up would more accurately define differences in health care consumption. On the other hand, QoL outcomes may become confounded by additional co- morbidity as follow-up extends therefore affecting the QALY calculation and coinciding ICER. Furthermore, longer follow-up might result in a higher dropout rate as the participants’ burden increases over time.
A solution would be to build a decision-model to test cost-effectiveness of the
intervention over a longer period than the time horizon of the trial. However,
decision models might not reflect clinical practice. Another limitation in this 9 study is that our analyses in health care consumption were not constricted to
costs related to AF only. Because cardiac surgery is predominantly performed
in the elderly, other co-morbidity may cause significant costs during follow- up.
Differences in costs due to rhythm-related health care consumption might not
have been observable in this case. However, this limitation is shared with the
other studies available in the literature. Larger randomized studies are warranted
General discussion
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