143 Cost-effectiveness of botulinum neurotoxin A versus surgery for drooling: a randomized clinical trial 6 other health care centres. However, it must be noted that normally in our centre the prices per operation room team are not activity-based and an average price for medication, materials, and disposables is included for all interventions. The strength of this RCT is the prospective setup and the societal perspective approach, which includes the productivity loss of the caregivers. There are several limitations, however. The main one from the economic evaluation was that the questionnaire used was not validated for quality of life, so calculation of QALYs was not possible. This would be desirable in future research, as it would allow a comparison of the gain in quality-adjusted life-years with a willingness-topay threshold. Nor did we make use of a standardized ceiling ratio for the ICER. Therefore, we cannot determine whether two-duct ligation is more cost-effective than BoNT-A. However, the current data provide the first insight that lays the foundation for future analyses of cost-effectiveness. Furthermore, there was no blinding to treatment allocation; however, the fact that blinded evaluation of a recorded drooling quotient was very closely matched to an unblinded drooling quotient suggests that this did not noticeably influence the outcome of the study.10 We performed a sensitivity analysis for the duration of surgery. It seems, however, that there are myriad other sources of potential variation in the cost structure which we did not assess. A final limitation is the length of follow-up, especially because the wish for subsequent treatment was higher after BoNT-A injection. The use of cost diaries gave some valuable insight into the indirect costs made in the first 2 weeks. Although we assume that the larger part of the productivity loss would occur during this period, we think that this study would have benefited from a longer registration of the cost diaries. However, one could speculate that compliance would reduce when extending the time horizon for a cost diary. For now,
RkJQdWJsaXNoZXIy MjY0ODMw