Proefschrift

Chapter 8 108 effectiveness gain, or willing to accept as savings for effectiveness loss. The CEAC represents the probability that, given a certain threshold for the willingness to pay for an extra point on the LEFS or for a QALY, the intervention is cost-effective. A CEAC is constructed by taking certain thresholds (€) and calculating the percentage of the 5,000 bootstrapped ICERs that are below each threshold, and therefore cost-effective, given that threshold. Due to uncertainty on the monetary threshold per QALY gained, alternative values ranging from € 0 to €80,000 were used in the cost-utility analysis.29 However, the exact threshold value is unknown, and there are no exact guidelines available in the Netherlands. Although in general €18,000 is accepted as the threshold value per QALY for preventive care in the Netherlands.29 However, the Dutch Council for Public Health and Health Care recommends relating the threshold of the costs of a QALY to the burden of disease, with a limit of €80,000 per QALY for diseases with a maximum loss in health status.29 Despite the absence of clear guidelines, we have chosen for a €50,000 threshold, which will be broad enough to capture the relevant threshold values in this study. Since the value that society might place on a unit reduction in LEFS score is unknown, its benefit cannot be defined. Finally, sensitivity analyses were performed. The base case includes all patients including those with and without paid job. A sensitivity analysis to assess the difference between these groups was conducted. The approach was similar to that of the base case. The outcomes were compared with the outcomes of the base case. Also, to provide a broader coverage of important health domains and scores for various purposes30 when calculating the cost-utility, a sensitivity analysis was conducted using scores from the SF-12 to calculate the QALYs gained instead those of the EQ-5D. In the base-case analysis, regression correction was used for the baseline costs and QALYs. Lastly, a sensitivity analysis including only healthcare costs was conducted. To conduct a sensitivity analysis only the healthcare costs were considered when calculating the cost-effectiveness and the cost-utility. The medical ethics committee of Maastricht University Medical Center, Maastricht, the Netherlands approved this study, reference number: METC 16–4-236. Patient’s informed consent to participate was obtained from all patients. Results Baseline characteristics participants This cohort study included 106 patients, N=53 both in the PWB and the RWB group. No significant differences in gender, age, employee, ASA type, type of fracture, number of surgical interventions and in hospital length of stay were found between the PWB and

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