Mylène Jansen

User-friendliness of a dedicated KJD device 137 7 As most of the answers were not normally distributed, Mann-Whitney U tests and mean with IQR were used for all parameters. For 6/25 (24%) of the questions a statistically significant difference in favor of the DD device is seen. For all other questions, scores were all in the direction of benefit for the DD device, but not statistically different between both devices (all p> 0.05). Based on responses of patients included in this study and on predetermined DD device characteristics (Table 1), 3 questionnaire aspects were identified as most relevant in experiencing user-friendliness: the incidence of clothes catching the device (question 2), the pin care (question 7), and the harm to the contralateral leg (question 14). These were aspects that patients specifically indicated as important with respect to user-friendliness during treatment when they completed their questionnaire. Moreover, these items were also considered as points that were likely important in reducing treatment burden during the development of the device. Detailed results on these aspects are provided in Figure 3 demonstrating favor for the DD with the latter 2 aspects statistically significant (both p< 0.004). Figure 3 : Individual patients’ user-friendliness scores for the 3 aspects considered the most relevant by included patients. Each dot represents a patient’s given score, with 10 the best score with respect to user-friendliness, while the lines indicate mean and standard deviation. The p- values indicate statistical significance of the differences between groups (bold values indicate statistical significance, p< 0.05). CD: concept distraction; DD: dedicated distraction. A statistically significant difference was found for the ease of performing pin care between patients with (median 5.0, IQR 2.3) and without (median 9.5, IQR 2.3) developed pin tract infections ( p= 0.001). Data for direct comparison of the CD device and the DD device based on the response of 3 patients who were treated over time with both devices is given in Figure 4. The overall performance of the DD device appears to be somewhat better compared to the CD device for questions regarding device characteristics, as the 3 patients more often indicated that the DD