The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
James O Lindsay - One of the best experts on this subject based on the ideXlab platform.
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cost effectiveness of Scheduled Maintenance treatment with infliximab for pediatric crohn s disease
Value in Health, 2010Co-Authors: Yogesh Suresh Punekar, Thomas Sunderland, Neil Hawkins, James O LindsayAbstract:ABSTRACT Background Infliximab recently became the only biologic approved for use in pediatric patients with severe active Crohn's disease (CD). Objectives To estimate the cost-effectiveness of Scheduled Maintenance treatment with infliximab compared with standard care in children suffering from severe active CD over 5 years from the UK National Health Service perspective. Methods A Markov model was constructed to simulate the progression of a hypothetical cohort of CD children through predefined health states on Scheduled Maintenance treatment with infliximab (5 mg/kg). The data to populate the model came from infliximab trials from Targan et al., ACCENT I, and REACH. The health states included in the model were remission, responding active disease, nonresponding active disease, surgery, postsurgery remission, postsurgery complications, and death. Standard care, comprising immunomodulators, and/or corticosteroids were used as a comparator. The primary outcome was quality-adjusted life-years (QALY) estimated using the EuroQol (EQ-5D) from a European CD population. To account for the weight-based dosing of infliximab, a baseline patient weight of 40 kg that increased by 5 kg/year up to 60 kg was used. The costs and outcomes were discounted at 3.5% over a period of 5 years. Probabilistic sensitivity analyses were performed by varying the infliximab efficacy estimates, costs, and utilities. Results The incremental cost-effectiveness ratio (ICER) for infliximab treatment was £14,607 compared with standard care. The sensitivity analyses revealed the treatment effect of infliximab to be the most influential parameter with ICERs ranging from £10,480 to £37,017. Assuming a willingness to pay of £30,000 per QALY, the probability of infliximab being cost-effective is 78.6%. Conclusion Scheduled Maintenance treatment with infliximab (5 mg/kg) is likely to be a cost-effective treatment in children suffering from severe active CD under an 8-week Maintenance program.
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health economic analysis cost effectiveness of Scheduled Maintenance treatment with infliximab for crohn s disease modelling outcomes in active luminal and fistulizing disease in adults
Alimentary Pharmacology & Therapeutics, 2008Co-Authors: James O Lindsay, Yogesh Suresh Punekar, James Morris, Guy ChungfayeAbstract:Summary Background Infliximab has been shown to be efficacious in moderate-to-severe Crohn’s disease (CD). Aim To evaluate the cost-effectiveness of Scheduled Maintenance treatment with infliximab in luminal and fistulizing CD patients. Methods Markov models were constructed to simulate the progression of adult CD patients with and without fistulae during treatment with infliximab (5 mg/kg). Transitions were estimated from published clinical trials of infliximab. Standard care, comprising immunomodulators and/or corticosteroids was used as a comparator. An average weight of 60 kg was used to estimate the dose of infliximab. The costs and outcomes were discounted at 3.5% over 5 years. The primary effectiveness measurement was quality-adjusted life years (QALYs) estimated using EQ-5D. One-way and probabilistic sensitivity analyses were performed by varying the infliximab efficacy estimates, costs and utilities. Results The incremental cost per QALY gained was £26 128 in luminal CD and £29 752 in fistulizing CD at 5 years. Results were robust and remained in the range of £23 752–£38 848 for luminal CD and £27 047–£44 206 for fistulizing CD. Patient body weight was the most important factor affecting cost-effectiveness. Conclusion Eight-week Scheduled Maintenance treatment with infliximab is a cost-effective treatment for adult patients suffering from active luminal or fistulizing CD.
Yogesh Suresh Punekar - One of the best experts on this subject based on the ideXlab platform.
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cost effectiveness of Scheduled Maintenance treatment with infliximab for pediatric crohn s disease
Value in Health, 2010Co-Authors: Yogesh Suresh Punekar, Thomas Sunderland, Neil Hawkins, James O LindsayAbstract:ABSTRACT Background Infliximab recently became the only biologic approved for use in pediatric patients with severe active Crohn's disease (CD). Objectives To estimate the cost-effectiveness of Scheduled Maintenance treatment with infliximab compared with standard care in children suffering from severe active CD over 5 years from the UK National Health Service perspective. Methods A Markov model was constructed to simulate the progression of a hypothetical cohort of CD children through predefined health states on Scheduled Maintenance treatment with infliximab (5 mg/kg). The data to populate the model came from infliximab trials from Targan et al., ACCENT I, and REACH. The health states included in the model were remission, responding active disease, nonresponding active disease, surgery, postsurgery remission, postsurgery complications, and death. Standard care, comprising immunomodulators, and/or corticosteroids were used as a comparator. The primary outcome was quality-adjusted life-years (QALY) estimated using the EuroQol (EQ-5D) from a European CD population. To account for the weight-based dosing of infliximab, a baseline patient weight of 40 kg that increased by 5 kg/year up to 60 kg was used. The costs and outcomes were discounted at 3.5% over a period of 5 years. Probabilistic sensitivity analyses were performed by varying the infliximab efficacy estimates, costs, and utilities. Results The incremental cost-effectiveness ratio (ICER) for infliximab treatment was £14,607 compared with standard care. The sensitivity analyses revealed the treatment effect of infliximab to be the most influential parameter with ICERs ranging from £10,480 to £37,017. Assuming a willingness to pay of £30,000 per QALY, the probability of infliximab being cost-effective is 78.6%. Conclusion Scheduled Maintenance treatment with infliximab (5 mg/kg) is likely to be a cost-effective treatment in children suffering from severe active CD under an 8-week Maintenance program.
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a model of the long term cost effectiveness of Scheduled Maintenance treatment with infliximab for moderate to severe ulcerative colitis
Alimentary Pharmacology & Therapeutics, 2008Co-Authors: H H Tsai, Yogesh Suresh Punekar, James Morris, P FortunAbstract:Summary Background Infliximab (IFX) has been shown to be efficacious in moderate-severe ulcerative colitis (UC). Aim To evaluate the cost-effectiveness of a Scheduled Maintenance treatment (SMT) with IFX in moderate-severe UC patients. Methods A Markov model was constructed to simulate the progression of a cohort of moderate-severe UC patients treated with IFX (5 mg/kg) SMT. Transitions were estimated from two phase III trials of IFX (ACT I and ACT II). Standard care, comprising immunomodulators and/or corticosteroids was used as a comparator. Two separate treatment strategies were evaluated – continued treatment in IFX responders and continued treatment in IFX patients achieving remission. The dose of IFX was estimated for a 73 kg typical UC patient in the UK. The results were calculated over 10 years using a discount rate of 3.5% for costs and outcomes. The outcome measure was quality-adjusted life years (QALYs) estimated using EQ-5D. Sensitivity analyses explored the uncertainty around the results. Results The incremental cost effectiveness ratio (ICER) for IFX was £27 424 in the responder strategy and £19 696 in the remission strategy at 10 years. In sensitivity analysis, the ICER for IFX in the responder strategy ranged from £21 066 to £86 322 and in the remission strategy ranged from £14 728 to £46 765. The model time horizon and patient body weight were important factors affecting results. Conclusion Eight-week SMT with IFX appears to be a cost-effective treatment option for adult patients suffering from moderate to severe UC.
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health economic analysis cost effectiveness of Scheduled Maintenance treatment with infliximab for crohn s disease modelling outcomes in active luminal and fistulizing disease in adults
Alimentary Pharmacology & Therapeutics, 2008Co-Authors: James O Lindsay, Yogesh Suresh Punekar, James Morris, Guy ChungfayeAbstract:Summary Background Infliximab has been shown to be efficacious in moderate-to-severe Crohn’s disease (CD). Aim To evaluate the cost-effectiveness of Scheduled Maintenance treatment with infliximab in luminal and fistulizing CD patients. Methods Markov models were constructed to simulate the progression of adult CD patients with and without fistulae during treatment with infliximab (5 mg/kg). Transitions were estimated from published clinical trials of infliximab. Standard care, comprising immunomodulators and/or corticosteroids was used as a comparator. An average weight of 60 kg was used to estimate the dose of infliximab. The costs and outcomes were discounted at 3.5% over 5 years. The primary effectiveness measurement was quality-adjusted life years (QALYs) estimated using EQ-5D. One-way and probabilistic sensitivity analyses were performed by varying the infliximab efficacy estimates, costs and utilities. Results The incremental cost per QALY gained was £26 128 in luminal CD and £29 752 in fistulizing CD at 5 years. Results were robust and remained in the range of £23 752–£38 848 for luminal CD and £27 047–£44 206 for fistulizing CD. Patient body weight was the most important factor affecting cost-effectiveness. Conclusion Eight-week Scheduled Maintenance treatment with infliximab is a cost-effective treatment for adult patients suffering from active luminal or fistulizing CD.
Cccc Water - One of the best experts on this subject based on the ideXlab platform.
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a predictive method for the estimation of material demand for aircraft non routine Maintenance
Computers & Education, 2013Co-Authors: M. Zorgdrager, B H L Boesten, Wim J C Verhagen, Richard Curran, Cccc WaterAbstract:A method is developed to forecast material demand caused by aircraft non-routine Maintenance. Non-routine material consumption is linked to Scheduled Maintenance tasks to gain insight in demand patterns. Subsequently, a suitable prediction model can be applied to forecast material demand. To test this approach, a structural part selection of the Boeing 737NG fleet of KLM Royal Dutch Airlines has been sampled to form a test case. Several regression and stochastic models have been applied to the part selection to judge model fit and validity. Resulting from this analysis, the Exponential Moving Average (EMA) was chosen as superior model for its small error values and ability to capture general demand trends. The forecast method incorporating the EMA model has been validated by forecasting and comparison against an independent dataset. Concluding, the non-routine Maintenance forecast method, comprising the non-routine material consumption forecasts linked to Scheduled Maintenance tasks, can be used to produce material predictions expressed in probability and average quantity figures for upcoming Maintenance checks.
Gordon R Greenberg - One of the best experts on this subject based on the ideXlab platform.
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association of trough serum infliximab to clinical outcome after Scheduled Maintenance treatment for crohn s disease
Clinical Gastroenterology and Hepatology, 2006Co-Authors: Elana Maser, Mark S Silverberg, Renata Villela, Gordon R GreenbergAbstract:Background & Aims: The effect of infliximab infused at Scheduled intervals on antibody formation, preinfusion trough serum concentrations of infliximab, and their clinical significance was evaluated in patients with Crohn's disease. Methods: Antibodies to infliximab and trough serum infliximab were measured in 105 patients with Crohn's disease treated with 5 mg/kg infliximab for induction followed by Maintenance episodic re-treatment (n = 23) or Scheduled therapy at 6- to 8-week intervals (n = 82). Results: After a median of 14 infusions (range, 2–45), 21% of patients had detectable antibodies, 25% were antibody negative, and 54% were antibody inconclusive. Antibody formation was higher after episodic compared with Scheduled treatment (39% vs 16%; P = .036) and was associated with a higher rate of infusion reactions (50% vs 21%; P = .018). Ninety patients continued Maintenance Scheduled therapy beyond 12 months including 12 converted episodic patients, with a median follow-up of 23 months (range, 16–68 months). The rate of clinical remission was higher for patients with a detectable trough serum infliximab compared with patients in whom serum infliximab was undetectable, including those without antibodies (82% vs 6%; P P P Conclusions: For Crohn's disease patients treated with Scheduled Maintenance infusions of infliximab, the trough serum concentration of infliximab predicts clinical outcome. Factors in addition to antibody formation, likely pharmacokinetic, modulate serum infliximab and thus the response to infliximab therapy.
Christian Bes - One of the best experts on this subject based on the ideXlab platform.
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A cost driven predictive Maintenance policy for structural airframe Maintenance
Chinese Journal of Aeronautics, 2017Co-Authors: Yiwei Wang, Nicolas Binaud, Christian Bes, Christian Gogu, Raphael T. Haftka, Nam H. KimAbstract:Airframe Maintenance is traditionally performed at Scheduled Maintenance stops. The decision to repair a fuselage panel is based on a fixed crack size threshold, which allows to ensure the aircraft safety until the next Scheduled Maintenance stop. With progress in sensor technology and data processing techniques, structural health monitoring (SHM) systems are increasingly being considered in the aviation industry. SHM systems track the aircraft health state continuously, leading to the possibility of planning Maintenance based on an actual state of aircraft rather than on a fixed schedule. This paper builds upon a model-based prognostics framework that the authors developed in their previous work, which couples the Extended Kalman filter (EKF) with a first-order perturbation (FOP) method. By using the information given by this prognostics method, a novel cost driven predictive Maintenance (CDPM) policy is proposed, which ensures the aircraft safety while minimizing the Maintenance cost. The proposed policy is formally derived based on the trade-off between probabilities of occurrence of Scheduled and unScheduled Maintenance. A numerical case study simulating the Maintenance process of an entire fleet of aircrafts is implemented. Under the condition of assuring the same safety level, the CDPM is compared in terms of cost with two other Maintenance policies: Scheduled Maintenance and threshold based SHM Maintenance. The comparison results show CDPM could lead to significant cost savings.
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synchronizing condition based Maintenance with necessary Scheduled Maintenance
53rd AIAA ASME ASCE AHS ASC Structures Structural Dynamics and Materials Conference<BR>20th AIAA ASME AHS Adaptive Structures Conference<BR&g, 2012Co-Authors: Sriram Pattabhiraman, Christian Gogu, Raphael T. Haftka, Nam Kim, Christian BesAbstract:Structural airframe Maintenance is a subset of Scheduled Maintenance, and is performed at regular intervals to detect and repair cracks that would otherwise affect the safety of the airplane. It has been observed that only a fraction of airplanes undergo structural airframe Maintenance at earlier Scheduled Maintenance times. But, intrusive inspection of all panels on the airplanes need to be performed at the time of Scheduled Maintenance to ascertain the presence/absence of large cracks critical to the safety of the airplane. Recently, structural health monitoring (SHM) techniques have been developed. They use onboard sensors and actuators to assess the current damage status of the airplane, and can be used as a tool to skip the structural airframe Maintenance, whenever deemed un-necessary. Two Maintenance philosophies, Sched-SHM and CBM-skip, have been developed in this paper, to skip unnecessary structural airframe Maintenances using on-board SHM system. A cost model is developed to quantify the savings of these Maintenance philosophies over Scheduled Maintenance.
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Skipping unnecessary structural airframe Maintenance using an on-board structural health monitoring system
Proceedings of the Institution of Mechanical Engineers Part O: Journal of Risk and Reliability, 2012Co-Authors: Sriram Pattabhiraman, Nam H. Kim, Christian Gogu, Raphael T. Haftka, Christian BesAbstract:Structural airframe Maintenance is a subset of Scheduled Maintenance, and is performed at regular intervals to detect and repair cracks that would otherwise affect the safety of the airplane. It has been observed that only a fraction of airplanes undergo structural airframe Maintenance at earlier Scheduled Maintenance times. But, intrusive inspection of all panels on the airplanes needs to be performed at the time of Scheduled Maintenance to ascertain the presence/absence of large cracks critical to the safety of the airplane. Recently, structural health monitoring techniques have been developed. They use on-board sensors and actuators to assess the current damage status of the airplane, and can be used as a tool to skip the structural airframe Maintenance whenever deemed unnecessary. Two Maintenance philosophies, Scheduled structural health monitoring and condition-based Maintenance skip, have been developed in this article to skip unnecessary structural airframe Maintenances using the on-board structural health monitoring system. A cost model is developed to quantify the savings of these Maintenance philosophies over Scheduled Maintenance.
