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Manuela A Joore - One of the best experts on this subject based on the ideXlab platform.
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eliciting patients preferences for elastic Compression Stocking therapy after deep vein thrombosis potential for improving compliance
Journal of Thrombosis and Haemostasis, 2016Co-Authors: A C Bouman, A Ten J Catehoek, Carmen D Dirksen, Manuela A JooreAbstract:Essentials Elastic Compression Stocking (ECS) therapy is used to prevent post-thrombotic syndrome (PTS). We aimed to elicit patient preferences regarding ECS therapy after deep vein thrombosis. The most valued attributes were PTS risk reduction and the ability to put on the ECS independently. Heterogeneous results with respect to education level stress the importance of proper counselling. SummaryBackground Elastic Compression Stocking (ECS) therapy is used for prevention of post-thrombotic syndrome (PTS) after deep vein thrombosis (DVT). Current evidence on its effectiveness is conflicting. Compliance, a major determinant of the effectiveness of ECS therapy, remained largely ignored in former studies. Objectives To gain insight into preferences regarding ECS therapy in patients after DVT. Patients/methods A discrete choice experiment was conducted 3 months after DVT in patients enrolled in the IDEAL DVT study, a randomized controlled trial comparing 2 years of ECS therapy with individually tailored duration of ECS therapy for the prevention of PTS. Nine unlabeled, forced-choice sets of two hypothetical types of ECS were presented to each patient. Data were analyzed with multinomial logit models. Results The respondent sample consisted of 81% (300/369) of invited patients. The most important determinants of preference were PTS risk reduction and putting on the ECS. Patients were willing to increase the duration of therapy by 1 year if this increases the PTS risk reduction with 10%. Patients accepted an increase in the risk of PTS of 29% if they were able to put on the ECS themselves. Preferences were heterogeneous with respect to education level. Conclusions Reduction of the risk of PTS and the ability to put on the ECS without help are the most important characteristics of ECS therapy. Physicians should pay considerable attention to patient education regarding PTS. In addition, patients should be supported in their ability to put on and take off the ECS independently. These rather simple interventions could improve compliance.
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sample size estimation for non inferiority trials frequentist approach versus decision theory approach
PLOS ONE, 2015Co-Authors: A C Bouman, A Ten J Catehoek, Bram L T Ramaekers, Manuela A JooreAbstract:Background Non-inferiority trials are performed when the main therapeutic effect of the new therapy is expected to be not unacceptably worse than that of the standard therapy, and the new therapy is expected to have advantages over the standard therapy in costs or other (health) consequences. These advantages however are not included in the classic frequentist approach of sample size calculation for non-inferiority trials. In contrast, the decision theory approach of sample size calculation does include these factors. The objective of this study is to compare the conceptual and practical aspects of the frequentist approach and decision theory approach of sample size calculation for non-inferiority trials, thereby demonstrating that the decision theory approach is more appropriate for sample size calculation of non-inferiority trials. Methods The frequentist approach and decision theory approach of sample size calculation for non-inferiority trials are compared and applied to a case of a non-inferiority trial on individually tailored duration of elastic Compression Stocking therapy compared to two years elastic Compression Stocking therapy for the prevention of post thrombotic syndrome after deep vein thrombosis. Results The two approaches differ substantially in conceptual background, analytical approach, and input requirements. The sample size calculated according to the frequentist approach yielded 788 patients, using a power of 80% and a one-sided significance level of 5%. The decision theory approach indicated that the optimal sample size was 500 patients, with a net value of €92 million. Conclusions This study demonstrates and explains the differences between the classic frequentist approach and the decision theory approach of sample size calculation for non-inferiority trials. We argue that the decision theory approach of sample size estimation is most suitable for sample size calculation of non-inferiority trials.
A C Bouman - One of the best experts on this subject based on the ideXlab platform.
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eliciting patients preferences for elastic Compression Stocking therapy after deep vein thrombosis potential for improving compliance
Journal of Thrombosis and Haemostasis, 2016Co-Authors: A C Bouman, A Ten J Catehoek, Carmen D Dirksen, Manuela A JooreAbstract:Essentials Elastic Compression Stocking (ECS) therapy is used to prevent post-thrombotic syndrome (PTS). We aimed to elicit patient preferences regarding ECS therapy after deep vein thrombosis. The most valued attributes were PTS risk reduction and the ability to put on the ECS independently. Heterogeneous results with respect to education level stress the importance of proper counselling. SummaryBackground Elastic Compression Stocking (ECS) therapy is used for prevention of post-thrombotic syndrome (PTS) after deep vein thrombosis (DVT). Current evidence on its effectiveness is conflicting. Compliance, a major determinant of the effectiveness of ECS therapy, remained largely ignored in former studies. Objectives To gain insight into preferences regarding ECS therapy in patients after DVT. Patients/methods A discrete choice experiment was conducted 3 months after DVT in patients enrolled in the IDEAL DVT study, a randomized controlled trial comparing 2 years of ECS therapy with individually tailored duration of ECS therapy for the prevention of PTS. Nine unlabeled, forced-choice sets of two hypothetical types of ECS were presented to each patient. Data were analyzed with multinomial logit models. Results The respondent sample consisted of 81% (300/369) of invited patients. The most important determinants of preference were PTS risk reduction and putting on the ECS. Patients were willing to increase the duration of therapy by 1 year if this increases the PTS risk reduction with 10%. Patients accepted an increase in the risk of PTS of 29% if they were able to put on the ECS themselves. Preferences were heterogeneous with respect to education level. Conclusions Reduction of the risk of PTS and the ability to put on the ECS without help are the most important characteristics of ECS therapy. Physicians should pay considerable attention to patient education regarding PTS. In addition, patients should be supported in their ability to put on and take off the ECS independently. These rather simple interventions could improve compliance.
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sample size estimation for non inferiority trials frequentist approach versus decision theory approach
PLOS ONE, 2015Co-Authors: A C Bouman, A Ten J Catehoek, Bram L T Ramaekers, Manuela A JooreAbstract:Background Non-inferiority trials are performed when the main therapeutic effect of the new therapy is expected to be not unacceptably worse than that of the standard therapy, and the new therapy is expected to have advantages over the standard therapy in costs or other (health) consequences. These advantages however are not included in the classic frequentist approach of sample size calculation for non-inferiority trials. In contrast, the decision theory approach of sample size calculation does include these factors. The objective of this study is to compare the conceptual and practical aspects of the frequentist approach and decision theory approach of sample size calculation for non-inferiority trials, thereby demonstrating that the decision theory approach is more appropriate for sample size calculation of non-inferiority trials. Methods The frequentist approach and decision theory approach of sample size calculation for non-inferiority trials are compared and applied to a case of a non-inferiority trial on individually tailored duration of elastic Compression Stocking therapy compared to two years elastic Compression Stocking therapy for the prevention of post thrombotic syndrome after deep vein thrombosis. Results The two approaches differ substantially in conceptual background, analytical approach, and input requirements. The sample size calculated according to the frequentist approach yielded 788 patients, using a power of 80% and a one-sided significance level of 5%. The decision theory approach indicated that the optimal sample size was 500 patients, with a net value of €92 million. Conclusions This study demonstrates and explains the differences between the classic frequentist approach and the decision theory approach of sample size calculation for non-inferiority trials. We argue that the decision theory approach of sample size estimation is most suitable for sample size calculation of non-inferiority trials.
A Ten J Catehoek - One of the best experts on this subject based on the ideXlab platform.
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eliciting patients preferences for elastic Compression Stocking therapy after deep vein thrombosis potential for improving compliance
Journal of Thrombosis and Haemostasis, 2016Co-Authors: A C Bouman, A Ten J Catehoek, Carmen D Dirksen, Manuela A JooreAbstract:Essentials Elastic Compression Stocking (ECS) therapy is used to prevent post-thrombotic syndrome (PTS). We aimed to elicit patient preferences regarding ECS therapy after deep vein thrombosis. The most valued attributes were PTS risk reduction and the ability to put on the ECS independently. Heterogeneous results with respect to education level stress the importance of proper counselling. SummaryBackground Elastic Compression Stocking (ECS) therapy is used for prevention of post-thrombotic syndrome (PTS) after deep vein thrombosis (DVT). Current evidence on its effectiveness is conflicting. Compliance, a major determinant of the effectiveness of ECS therapy, remained largely ignored in former studies. Objectives To gain insight into preferences regarding ECS therapy in patients after DVT. Patients/methods A discrete choice experiment was conducted 3 months after DVT in patients enrolled in the IDEAL DVT study, a randomized controlled trial comparing 2 years of ECS therapy with individually tailored duration of ECS therapy for the prevention of PTS. Nine unlabeled, forced-choice sets of two hypothetical types of ECS were presented to each patient. Data were analyzed with multinomial logit models. Results The respondent sample consisted of 81% (300/369) of invited patients. The most important determinants of preference were PTS risk reduction and putting on the ECS. Patients were willing to increase the duration of therapy by 1 year if this increases the PTS risk reduction with 10%. Patients accepted an increase in the risk of PTS of 29% if they were able to put on the ECS themselves. Preferences were heterogeneous with respect to education level. Conclusions Reduction of the risk of PTS and the ability to put on the ECS without help are the most important characteristics of ECS therapy. Physicians should pay considerable attention to patient education regarding PTS. In addition, patients should be supported in their ability to put on and take off the ECS independently. These rather simple interventions could improve compliance.
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sample size estimation for non inferiority trials frequentist approach versus decision theory approach
PLOS ONE, 2015Co-Authors: A C Bouman, A Ten J Catehoek, Bram L T Ramaekers, Manuela A JooreAbstract:Background Non-inferiority trials are performed when the main therapeutic effect of the new therapy is expected to be not unacceptably worse than that of the standard therapy, and the new therapy is expected to have advantages over the standard therapy in costs or other (health) consequences. These advantages however are not included in the classic frequentist approach of sample size calculation for non-inferiority trials. In contrast, the decision theory approach of sample size calculation does include these factors. The objective of this study is to compare the conceptual and practical aspects of the frequentist approach and decision theory approach of sample size calculation for non-inferiority trials, thereby demonstrating that the decision theory approach is more appropriate for sample size calculation of non-inferiority trials. Methods The frequentist approach and decision theory approach of sample size calculation for non-inferiority trials are compared and applied to a case of a non-inferiority trial on individually tailored duration of elastic Compression Stocking therapy compared to two years elastic Compression Stocking therapy for the prevention of post thrombotic syndrome after deep vein thrombosis. Results The two approaches differ substantially in conceptual background, analytical approach, and input requirements. The sample size calculated according to the frequentist approach yielded 788 patients, using a power of 80% and a one-sided significance level of 5%. The decision theory approach indicated that the optimal sample size was 500 patients, with a net value of €92 million. Conclusions This study demonstrates and explains the differences between the classic frequentist approach and the decision theory approach of sample size calculation for non-inferiority trials. We argue that the decision theory approach of sample size estimation is most suitable for sample size calculation of non-inferiority trials.
Michael Junger - One of the best experts on this subject based on the ideXlab platform.
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interface pressure and venous drainage of two Compression Stocking types in healthy volunteers and in patients with hemodynamic disturbances of the legs
Clinical Hemorheology and Microcirculation, 2015Co-Authors: Helene Riebe, Hermann Haase, Wolfgang Konschake, Michael JungerAbstract:Standard of care in the therapy of chronic venous insufficiency (CVI) is the use of graduated elastic Stockings (GECS). This paper is based on a prospective, mono-centric, open randomised, controlled and cross over study and discusses the hemodynamic effects of GECS and inverse graduated Compression Stockings (PECS) in 32 healthy volunteers and 32 patients with CVI and the consecutive impact on comfort. The application of Stockings was performed sequentially, the allocation of the first Stocking was randomized and double blind, wearing period for each Stocking type about 7 days with one week of break between wearing periods. Measurements of the interface pressure were carried out by Picopress®(Microlab Elettronica, Italy) and the venous drainage were registered by strain gauge plethysmography. Mean interface pressure: GECS (level B1): 27.3 mmHg; GECS (level C): 19,6 mmHg; PECS (level B1): 17,8 mmHg; PECS (level C): 24,7 mmHg. Significant increase of EF and decrease of VFI by wearing both types of Compression Stockings, comparatively GESC resulted in a significantly greater improvement of EF than the PECS. PECS were significantly easier to don and put on compared to the GECS, the PECS tended to slip towards the foot more often.
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Cutaneous vasomotion in patients with chronic venous insufficiency and the influence of Compression therapy.
Clinical hemorheology and microcirculation, 2009Co-Authors: S. Heising, Hermann Haase, K. Sippel, F. Riedel, Michael JungerAbstract:We investigated in patients with chronic venous insufficiency (CVI) and after Compression therapy the fluxmotion within characteristic frequency bands, which were described earlier by Bray ciy and Stefanovska (Bull. Math. Biol. 60 (1998), 919-935). Therefore, the frequency spectra of laser Doppler flux data of the 36 patient's legs were compared with 41 legs of healthy subjects. In addition, 14 patients with CVI wore a Compression Stocking (interface pressure: 25-32 mmHg) or Compression bandages and were measured after 4 weeks therapy. Data were analyzed by means of a Wavelet packet transformation (a com- bination of the Daubechies filter of order 4 and the Haar filter). We found significant differences between the patients and the healthy subjects in the frequency intervals of myogenic 0.06- 0.16 Hz, respiratory 0.16-0.6 Hz and heart activity 0.6-1.6 Hz ( p< 0.05, Mann-Whitney U test). Furthermore, the main energy peak height in these frequency intervals increased with the severity of venous disease and was highest in patients with venous leg ulceration. Compression therapy had a significant influence in myogenic vessel activity, which has been proved by a positive frequency shift of 20% (p = 0.007, one-sided by the exact Wilcoxon test). In venous disease fluxmotion was increased. Compression therapy over a period of 4 weeks improved myogenic vessel activity.
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efficacy and tolerability of an ulcer Compression Stocking for therapy of chronic venous ulcer compared with a below knee Compression bandage results from a prospective randomized multicentre trial
Current Medical Research and Opinion, 2004Co-Authors: Michael Junger, Ralf Kohnen, Uwe Wollina, Eberhard RabeAbstract:SUMMARYObjective: To investigate the possibility of improving healing rates in ulcus cruris venosum by using an ulcer Compression Stocking (U-Stocking) (Venotrain* ulcertec) as compared to Compression bandages.Research design and setting: Prospective, multicentre, open-labelled, randomized, active-controlled study with blinded assessment of the primary endpoint. Sixteen phlebology outpatient clinics in Germany or the Netherlands or German medical practices specialized in phlebology.Patients and methods: 134 patients with venous leg ulcers entered the study. Among others, patients with infected ulcer or obesity were excluded. 121 patients were eligible for primary efficacy analyses. U-Stocking or bandages applied for at least eight hours per day and for up to 12 weeks. The primary endpoint was the healing rate after 12 weeks as assessed by planimetric measures. The secondary outcome variables were time to healing, changes in ulcer size (planimetry), experience of use and patient compliance.Main outcome mea...
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interface pressure under a ready made Compression Stocking developed for the treatment of venous ulcers over a period of six weeks
Vasa-european Journal of Vascular Medicine, 2003Co-Authors: Michael Junger, H M HafnerAbstract:Background: The most important component in the treatment of venous ulcers is Compression therapy. The function of Compression therapy is the pressure exterted on the extrafascial and intrafascial venous system. Therefore the interface pressure of specially designed Compressions Stockings for the treatment of venous ulcers are in the focus of interest. Patients and methods: We examined 20 patients (6 men and 14 women) with chronic venous insufficiency in CEAP stages C 80-4 EPAs 1-3 P R ). Interface pressure was measured under the Venotrain® Ulcertec over an observation period of six weeks with piezoresistance sensors at four different sites on the lower leg and with the patient in different body positions. Results:Resting pressure supine at the ankle corresponded to Compression class III and was constant over the period of six weeks (mean difference 2.8 SD 15.3 mmHg, p = 0.49). Working pressure explained as the quotient of maximum pressure during tiptoing/resting pressure in standing position was initially at the ankle 1.70 SD 0.44 and after 6 weeks 1.44 SD 0.29 (mean difference 0.27 SD 0.42, p < 0.03). Conclusions: The Compression Stocking maintained a therapeutically effective pressure profile over a period of six weeks. Working interface pressure was comparable to that of short-stretch Compression bandages applied by an experienced bandager immediately after application.
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Compression Stocking in treatment of ulcus cruris an efficient alternative to bandages
Hautarzt, 2000Co-Authors: Hansmartin Hafner, B Vollert, A Schlez, Michael JungerAbstract:BACKGROUND AND OBJECTIVE The aim of the study was to measure the pressure exerted on the skin with application of the specially designed UlcerCare Compression Stocking for treatment of chronic venous leg ulcers and simultaneously to objectify the improvement in venous function. PATIENTS/METHODS Twenty patients with chronic venous insufficiency according to the CEAP Classification C1-4 EP AS, A14, AP, PR were examined. Static exerted pressure was measured while standing and the dynamic equivalent was measured during 10 repetitions of tip-toe exercise. The patients were wearing the standard Stocking JOBST Medical LegWear UlcerCare (Beiersdorf AG, Hamburg, Germany). As a control for the effectiveness of the therapy on venous hemodynamics, the lower leg volume, calculated using optoelectronically-measured lower leg circumference and venous reflux, determined by strain gauge plethysmographically-measured venous refill time, were used. RESULTS Use of the Compression Stocking system UlcerCare resulted in a decreased lower leg volume. This decrease was on average 5.3%, corresponding to 106 +/- 78 ml (p < 0.001). The calf and forefoot venous function parameters also improved. The venous refill time improved from 27.2 +/- 15.2 s to 45.0 +/- 27.4 s at the forefoot (p < 0.003) and from 10.5 +/- 4.5 s to 19.4 +/- 10.9 s at the calf (p < 0.002). The exerted pressure at the ankle while standing was 46.2 +/- 24.2 mmHg (resting pressure) and 48.5 +/- 27.2 mmHg during repetitive tip-toe exercises (mean exercise pressure). At the calf, the exerted pressure while standing was 40.7 +/- 26.9 mmHg (resting pressure) and during the repetitive tip-toe exercises it was 42.1 +/- 29.5 mmHg (mean exercise pressure). CONCLUSIONS The exerted pressure of the UlcerCare Compression Stocking is equivalent to that of a class 3 medical Compression Stocking. This newly developed Stocking diminishes venous reflux and reduces leg edema. These objectified effects suggest that the UlcerCare Stocking is effective as Compression therapy for venous ulcers.
Couzan Serge - One of the best experts on this subject based on the ideXlab platform.
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etude m ecanique des articles de contention et de leurs effets sur la jambe humaine mechanical investigation of Compression Stockings and of their effects on the human leg
arXiv: Medical Physics, 2009Co-Authors: Stéphane Avril, Laura Bouten, Sylvain Drapier, Couzan SergeAbstract:This paper presents a synthesis of different studies willing to bring a scientific insight into leg Compression, which is the process of applying external Compression forces onto the human leg with Stockings or socks, for enhancing the venous flow. It seems obvious that the pressure distribution on the leg affects the blood flow in the veins. However, the pressure distribution that leads to the optimal blood flow is not trivial, and it is different with regard to the application: medical treatment or recovering after an effort in sports. In order to improve the scientific knowledge about this topic, a numerical 2D model was set up for computing stress fields inside the leg, accounting for the actual material properties of both the Compression Stocking and of the leg biological tissues. Suitable identification methods, based either on model updating from digital image correlation (for the Compression Stockings), or on image warping and model updating from MRI scans (for the internal leg tissues), were developed for retrieving these material properties.