13 research outputs found

    Surface modification of HVOF thermal sprayed WC–CoCr coatings by laser treatment

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    In this work the affects of laser characteristics on microstructure and microhardness of high velocity oxygen fuel sprayed (HVOF) WC–CoCr coatings were investigated. The coating was deposited with a Sulzer Metco WokaJetℱ-400 kerosene fuel and the laser surface treatments were applied using CO2 laser with 10.6 ÎŒm wavelength. Large variations in surface properties were produced from variation in the laser processing parameters. In total, four levels of peak power (100, 200, 300 and 350 W), four levels of spot diameter (0.2, 0.4, 0.6 and 1 mm) and three levels of pulse repetition frequency (PRF) were investigated. An initial set of tests were followed by a more detailed 33 factorial design of experiments. Pulse repetition frequency and duty cycle were set in order to maintain the same overlap in the x and y directions for the raster scanned sample spot impact dimensions. Overlaps of 30% were used in the initial tests and 10% in the more detailed trials. The results have shown that care must be taken to keep the irradiance at a relatively low level compared to uncoated surfaces. High irradiance can in this case result in rough and porous surfaces. Lower levels of irradiance are shown to provide more uniform microstructures, reduced porosity and increased microhardness

    Vedolizumab for Treating Moderately to Severely Active Crohn’s Disease After Prior Therapy: An Evidence Review Group Perspective of a NICE Single Technology Appraisal

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    As part of its single technology appraisal process, the National Institute for Health and Care Excellence (NICE) invited the manufacturer of vedolizumab (Takeda UK) to submit evidence of the clinical effectiveness and cost effectiveness of vedolizumab for the treatment of patients with moderate-to-severe, active Crohn’s disease. The School of Health and Related Research (ScHARR) at the University of Sheffield was commissioned as the Evidence Review Group (ERG) and produced a critical review of the evidence of the clinical effectiveness and cost effectiveness of the technology, based upon the company’s submission to NICE. The GEMINI II and III trials formed the main supporting evidence for the intervention. Both studies were phase III, randomised, double-blind, placebo-controlled, multicentre trials designed to evaluate the efficacy and safety of vedolizumab. They included patients who were naĂŻve to tumour necrosis factor alpha antagonist (anti-TNF-α) therapy and patients who had an inadequate response to, loss of response to or intolerance of immunomodulators or anti-TNF-α agents. GEMINI II was designed to evaluate the efficacy and safety of vedolizumab as an induction treatment (dosing at weeks 0 and 2, with assessment at week 6) and maintenance treatment (during weeks 6–52). In contrast, GEMINI III was designed to evaluate the efficacy and safety of vedolizumab as an induction treatment only, with doses at weeks 0, 2 and 6, and assessment at weeks 6 and 10. In the absence of any direct head-to-head, randomised, controlled trials comparing vedolizumab with other relevant biologic therapies (adalimumab and infliximab) for the treatment of moderate-to-severe Crohn’s disease, the company conducted a network meta-analysis, which compared vedolizumab, adalimumab, infliximab and placebo for the outcomes of clinical response, enhanced clinical response, clinical remission and discontinuation due to adverse events. The company model estimated the incremental cost-effectiveness ratio (ICER) for vedolizumab compared with the standard of care (consisting of 5-aminosalicylic acids, corticosteroids and immunosuppressants) to be ÂŁ21,620 per quality-adjusted life-year (QALY) gained within the anti-TNF-α-failure population (which included a confidential patient access scheme for vedolizumab). The ICERs were above ÂŁ30,000 per QALY gained for the mixed intention-to-treat population (including both anti-TNF-α-naĂŻve and anti-TNF-α-failure populations) and in patients who were anti-TNF-α naĂŻve only. The ERG identified a number of limitations that were believed to limit the robustness of the results presented by the company. These limitations could not be addressed by the ERG without major restructuring of the economic model. Therefore, the ERG concluded that the results from the company’s model needed to be interpreted with caution and that it was unclear whether the ICERs would increase or decrease following amendment of the identified structural issues

    Ustekinumab for Treating Moderately to Severely Active Crohn’s Disease after Prior Therapy: An Evidence Review Group Perspective of a NICE Single Technology Appraisal

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    As part of the single technology appraisal (STA) process, the National Institute for Health and Care Excellence (NICE) invited Janssen to submit evidence on the clinical and cost effectiveness of their drug ustekinumab, an interleukin-12/23 inhibitor, for treating moderate-to-severe active Crohn’s disease (CD). The Centre for Reviews and Dissemination (CRD) and Centre for Health Economics (CHE) Technology Appraisal Group at the University of York was commissioned to act as the independent Evidence Review Group (ERG). This article provides a description of the Company’s submission, the ERG’s critical review of submitted evidence, and the resulting NICE guidance. The main supporting clinical evidence was derived from four well conducted, randomised controlled trials, comparing ustekinumab with placebo in two sub-populations (conventional care failure and anti-TNFα failure patients) of adults with moderate-to-severe CD. Three trials assessed treatment induction over 8 weeks, while the fourth recruited successfully induced patients into a maintenance trial for 1 year. These trials showed ustekinumab to be more effective than placebo in terms of its ability to induce and maintain clinical response and remission. In the absence of any direct head-to-head data, the Company conducted a network meta-analysis (NMA), which synthesised induction trial data on ustekinumab and relevant comparators (vedolizumab, adalimumab and infliximab) using placebo data as a common comparator. This analysis found ustekinumab to be of comparable efficacy to previously approved biologics in treatment induction. A ‘treatment sequence analysis’ compared long-term treatment efficacy, finding ustekinumab to be comparable in maintaining treatment response and remission to the three other biologic therapies. However, the ERG had identified many limitations and potential bias in this analysis, and urged caution when interpreting the results. The Company’s economic model estimated ustekinumab to be dominant in both sub-populations compared with conventional care; however, the ERG’s preferred base-case estimated an incremental cost-effectiveness ratio of ÂŁ109,279 in the conventional care failure sub-population, and ÂŁ110,967 in the anti-TNFα failure sub-population when compared with conventional care. However, the ERG identified significant failings in both the model structure and data inputs, which could not be addressed without complete restructuring. The ERG considered that the economic analysis presented by the Company failed to adequately address the decision problem specified in NICE’s scope. The NICE Appraisal Committee recommended ustekinumab within its market authorisation, on the grounds of sufficiently similar efficacy and costs to previously recommended biologic therapies. However, the ERG’s analyses demonstrated that all currently recommended biologics are unlikely to be cost effective relative to conventional care, raising broader questions regarding the appropriateness of cost-comparison exercises for decision making

    Developing a standard set of patient-centred outcomes for inflammatory bowel disease - an international, cross-disciplinary consensus

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    Background and Aims: Success in delivering value-based healthcare involves measuring outcomes that matter most to patients. Our aim was to develop a minimum Standard Set of patient-centred outcome measures for inflammatory bowel disease (IBD), for use in different healthcare settings. Methods: An international working group (n=25) representing patients, patient associations, gastroenterologists, surgeons, specialist nurses, IBD registries and patient-reported outcome measure (PROM) methodologists participated in a series of teleconferences incorporating a modified Delphi process. Systematic review of existing literature, registry data, patient focus groups and open review periods were used to reach consensus on a minimum set of standard outcome measures and risk adjustment variables. Similar methodology has been used in 21 other disease areas (www.ichom.org). Results: A minimum Standard Set of outcomes was developed for patients (aged ≄16) with IBD. Outcome domains included survival and disease control (survival, disease activity/remission, colorectal cancer, anaemia), disutility of care (treatment-related complications), healthcare utilisation (IBD-related admissions, emergency room visits) and patient-reported outcomes (including quality of life, nutritional status and impact of fistulae) measured at baseline and at 6 or 12 month intervals. A single PROM (IBD-Control questionnaire) was recommended in the Standard Set and minimum risk adjustment data collected at baseline and annually were included: demographics, basic clinical information and treatment factors. Conclusions: A Standard Set of outcome measures for IBD has been developed based on evidence, patient input and specialist consensus. It provides an international template for meaningful, comparable and easy-to-interpret measures as a step towards achieving value-based healthcare in IBD. (248 words)

    Developing a standard set of patient-centred outcomes for inflammatory bowel disease - an international, cross-disciplinary consensus

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    Background and Aims: Success in delivering value-based healthcare involves measuring outcomes that matter most to patients. Our aim was to develop a minimum Standard Set of patient-centred outcome measures for inflammatory bowel disease (IBD), for use in different healthcare settings. Methods: An international working group (n=25) representing patients, patient associations, gastroenterologists, surgeons, specialist nurses, IBD registries and patient-reported outcome measure (PROM) methodologists participated in a series of teleconferences incorporating a modified Delphi process. Systematic review of existing literature, registry data, patient focus groups and open review periods were used to reach consensus on a minimum set of standard outcome measures and risk adjustment variables. Similar methodology has been used in 21 other disease areas (www.ichom.org). Results: A minimum Standard Set of outcomes was developed for patients (aged ≄16) with IBD. Outcome domains included survival and disease control (survival, disease activity/remission, colorectal cancer, anaemia), disutility of care (treatment-related complications), healthcare utilisation (IBD-related admissions, emergency room visits) and patient-reported outcomes (including quality of life, nutritional status and impact of fistulae) measured at baseline and at 6 or 12 month intervals. A single PROM (IBD-Control questionnaire) was recommended in the Standard Set and minimum risk adjustment data collected at baseline and annually were included: demographics, basic clinical information and treatment factors. Conclusions: A Standard Set of outcome measures for IBD has been developed based on evidence, patient input and specialist consensus. It provides an international template for meaningful, comparable and easy-to-interpret measures as a step towards achieving value-based healthcare in IBD. (248 words).</p
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