1. |
- Bäck, Maria, 1978, et al.
(author)
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Home-based versus hospital-based supervised exercise or walk advice as treatment for intermittent claudication : Hembaserad jämfört med sjukhusbaserad handledd fysisk träning eller träningsråd som behandling vid claudicatio intermittens
- 2014
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Reports (other academic/artistic)abstract
- Method and patient group Intermittent claudication, the most common symptomatic presentation of peripheral arterial disease, is present in 7% of Swedish people aged 60 years or older. The progressive atherosclerotic process involves the development of stenoses and/or occlusions in the arteries propagating blood to the lower limbs. This causes effort-induced pain in the affected limb(s). Treatment is usually conservative and includes exercise therapy. Today, current practice in Sweden for patients with IC usually does not include hospital-based supervised exercise programs. A home-based supervised exercise program in a self-chosen environment might bridge the gap between the highly structured and costly hospital-based supervised exercise programs and ’go home and walk advice’. Question at issue Is home-based supervised exercise more effective than either unsupervised ‘go home and walk advice’, or hospital-based supervised exercise, for patients with intermittent claudication, in terms of walking distance, health related quality of life, symptoms, and risks associated with exercise? Studied risks and benefits for patients Ten articles were identified: two systematic reviews, six randomized controlled trials (RCT) and two cohort studies. The systematic reviews were only commented on. The quality of evidence (GRADE ⊕⊕) was low for all conclusions. Concluding remark Home-based supervised exercise for patients with intermittent claudication was compared with hospitalbased supervised exercise, or ‘go home and walk advice’. Six RCTs and two cohort studies were identified. There is low quality of evidence (GRADE ⊕⊕) that home-based supervised exercise, as compared with ‘go home and walk advice’, may slightly improve maximum and pain-free walking distance and result in little or no difference in health-related quality of life, and functional walking ability. There is low quality of evidence (GRADE ⊕⊕) that home-based supervised exercise may lead to less improvement in both maximum and pain-free walking distance than supervised hospital-based exercise, and result in little or no difference in health-related quality of life, and functional walking ability. There are no major ethical issues, and a reliable estimate of the total cost change is not possible, due to a total lack of reliable long-term data.
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2. |
- Djerf, Emelie, et al.
(author)
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The pan-ErbB receptor tyrosine kinase inhibitor canertinib promotes apoptosis of malignant melanoma in vitro and displays anti-tumor activity in vivo
- 2011
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In: Biochemical and Biophysical Research Communications - BBRC. - : Elsevier. - 0006-291X .- 1090-2104. ; 414:3, s. 563-568
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Journal article (peer-reviewed)abstract
- The ErbB receptor family has been suggested to constitute a therapeutic target for tumor-specific treatment of malignant melanoma. Here we investigate the effect of the pan-ErbB tyrosine kinase inhibitor canertinib on cell growth and survival in human melanoma cells in vitro and in vivo. Canertinib significantly inhibited growth of cultured melanoma cells, RaH3 and RaH5, in a dose-dependent manner as determined by cell counting. Half-maximum growth inhibitory dose (IC(50)) was approximately 0.8 mu M and by 5 mu M both cell lines were completely growth-arrested within 72 h of treatment. Incubation of exponentially growing RaH3 and RaH5 with 1 mu M canertinib accumulated the cells in the G(1)-phase of the cell cycle within 24 h of treatment without induction of apoptosis as determined by flow cytometry. Immunoblot analysis showed that 1 mu M canertinib inhibited ErbB1-3 receptor phosphorylation with a concomitant decrease of Akt-, Erk1/2- and Stat3 activity in both cell lines. In contrast to the cytostatic effect observed at doses less than= 5 mu M canertinib, higher concentrations induced apoptosis as demonstrated by the Annexin V method and Western blot analysis of PARP cleavage. Furthermore, canertinib significantly inhibited growth of RaH3 and RaH5 melanoma xenografts in nude mice. Pharmacological targeting of the ErbB receptors may prove successful in the treatment of patients with metastatic melanoma.
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3. |
- Djerf, Henrik, et al.
(author)
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Absence of Long-Term Benefit of Revascularization in Patients with Intermittent Claudication: Five-Year Results from the IRONIC Randomized Controlled Trial
- 2020
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In: Circulation: Cardiovascular Interventions. - 1941-7640 .- 1941-7632. ; 13:1
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Journal article (peer-reviewed)abstract
- © 2020 Lippincott Williams and Wilkins. All rights reserved. Background: The long-term benefit of revascularization for intermittent claudication is poorly understood. The aim of this study was to investigate the long-term effectiveness and cost-effectiveness compared with a noninvasive approach. Methods: The IRONIC trial (Invasive Revascularization or Not in Intermittent Claudication) randomized patients with mild-to-severe intermittent claudication to either revascularization + best medical therapy + structured exercise therapy (the revascularization group) or best medical therapy + structured exercise therapy (the nonrevascularization group). The health-related quality of life short form 36 questionnaire was primary outcome and disease-specific health-related quality of life (vascular quality of life questionnaire) and treadmill walking distances were secondary end points. Health-related quality of life has previously been reported superior in the revascularization group at 1- and 2-year follow-up. In this study, the 5-year results were determined. The cost-effectiveness of the treatment options was analyzed from a payer/healthcare standpoint. Results: Altogether, 158 patients were randomized in a 1:1 ratio. Regarding the primary end point, no intergroup differences were observed for the short form 36 sum or domain scores from baseline to 5 years, except for the short form 36 role emotional domain score, with greater improvement in the nonrevascularization group (n=116, P=0.007). No intergroup differences were observed in the vascular quality of life questionnaire total and domain scores (n=116, NS) or in treadmill walking distances (n=91, NS). A revascularization strategy resulted in almost twice the cost per patient compared with a noninvasive treatment approach ($13 098 versus $6965, P=0.02). Conclusions: After 5 years of follow-up, a revascularization strategy had lost its early benefit and did not result in any long-term improvement in health-related quality of life or walking capacity compared to a noninvasive treatment strategy. Revascularization was not a cost-effective treatment option from a payer/healthcare point of view. Clinical Trial Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01219842.
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4. |
- Djerf, Henrik, et al.
(author)
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Cost-effectiveness of revascularization in patients with intermittent claudication.
- 2018
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In: The British journal of surgery. - : Oxford University Press (OUP). - 1365-2168 .- 0007-1323. ; 105:13, s. 1742-1748
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Journal article (peer-reviewed)abstract
- Revascularization is a treatment option for patients with intermittent claudication. However, there is a lack of evidence to support its long-term benefits and cost-effectiveness. The aim of this study was to compare the cost-effectiveness of revascularization and best medical therapy (BMT) with that of BMT alone.Data were used from the IRONIC (Invasive Revascularization Or Not in Intermittent Claudication) RCT where consecutive patients with mild-to-severe intermittent claudication owing to aortoiliac or femoropopliteal disease were allocated to either BMT alone (including a structured, non-supervised exercise programme) or to revascularization together with BMT. Inpatient and outpatient costs were obtained prospectively over 24 months of follow-up. Mean improvement in quality-adjusted life-years (QALYs) was calculated based on responses to the EuroQol Five Dimensions EQ-5D-3 L™ questionnaire. Cost-effectiveness was assessed as the cost per QALY gained.A total of 158 patients were randomized, 79 to each group. The mean cost per patient in the BMT group was €1901, whereas it was €8280 in the group treated with revascularization in addition to BMT, with a cost difference of €6379 (95 per cent c.i. €4229 to 8728) per patient. Revascularization in addition to BMT resulted in a mean gain in QALYs of 0·16 (95 per cent c.i. 0·06 to 0·24) per patient, giving an incremental cost-effectiveness ratio of €42 881 per QALY.The costs associated with revascularization together with BMT in patients with intermittent claudication were about four times higher than those of BMT alone. The incremental cost-effectiveness ratio of revascularization was within the accepted threshold for public willingness to pay according to the Swedish National Guidelines, but exceeded that of the UK National Institute for Health and Care Excellence guidelines.
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5. |
- Djerf, Henrik, et al.
(author)
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Editor's Choice - Cost Effectiveness of Primary Stenting in the Superficial Femoral Artery for Intermittent Claudication: Two Year Results of a Randomised Multicentre Trial
- 2021
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In: European Journal of Vascular and Endovascular Surgery. - : Elsevier BV. - 1078-5884. ; 62:4, s. 576-582
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Journal article (peer-reviewed)abstract
- Objective: Invasive treatment of intermittent claudication (IC) is commonly performed, despite limited evidence of its cost effectiveness. IC symptoms aremainly caused by atherosclerotic lesions in the superficial femoral artery (SFA), and endovascular treatment is performed frequently. The aimof this studywas to investigate its cost effectiveness vs. noninvasive treatment. Methods: One hundred patients with IC due to lesions in the SFA were randomised to treatment with primary stenting, best medical treatment (BMT) and exercise advice (stent group), or to BMT and exercise advice alone (control group). Patients were recruited at seven hospitals in Sweden. For this analysis of cost effectiveness after 24 months, 84 patients with data on quality adjusted life years (QALY; based on the EuroQol Five Dimensions EQ5D 3L (TM) questionnaire) were analysed. Patient registry and imputed cost data were used for accumulated costs regarding hospitalisation and outpatient visits. Results: The mean cost per patient was (SIC)11 060 in the stent group and (SIC)4 787 in the control group, resulting in a difference of (SIC)6 273 per patient between the groups.The difference in mean QALYs between the groups was 0.26, in favour of the stent group, which resulted in an incremental cost effectiveness ratio (ICER) of (SIC)23 785 per QALY. Conclusion: The costs associated with primary stenting in the SFA for the treatment of IC were higher than for exercise advice and BMT alone. With concurrent improvement in health related quality of life, primary stenting was a cost effective treatment option according to the Swedish national guidelines (ICER < (SIC)50 000 - (SIC)70 000) and approaching the UK's National Institute for Health and Care Excellence threshold for willingness to pay (ICER < 20 pound 000 - 30 pound 000). From a cost effectiveness standpoint, primary stenting of the SFA can, in many countries, be used as an adjunct to exercise training advice, but it must be considered that successful implementation of structured exercise programmes and longer follow up may alter these findings.
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6. |
- Djerf, Henrik
(author)
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Invasive treatment for intermittent claudication - clinical outcomes and cost-effectiveness
- 2020
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Doctoral thesis (other academic/artistic)abstract
- Intermittent claudication (IC) is caused by obstructive arterial lesions and is characterized by effort-induced pain in the lower extremity, limiting walking distance, and reduced health-related quality of life (HRQoL). The prevalence of IC is increasing due to the ageing of the population, and the consequences of the economic effects are a global problem. The walking impairment can be reduced by exercise. Despite the paucity of evidence regarding long-term benefit and cost-effectiveness, invasive revascularization is also often performed. We wanted to investigate whether invasive treatment for IC is safe with regard to procedure-related limb loss, whether it is cost-effective, and whether it has long-term clinical benefit compared to exercise only. The Swedvasc registry was used to identify all revascularizations performed in Sweden for IC between 2008 and 2012. Amputations were captured using the National Patient Registry (Paper I). Cost-effectiveness was analyzed in two prospective randomized trials, the IRONIC trial and a randomized trial investigating stenting of the superficial femoral artery in IC (papers II, III, and IV). The long-term clinical effect was analyzed in the IRONIC trial (paper III). HENRIK DJERF 5 We found a low rate of major amputations during the first year after revascularization for IC: 0.2% (Paper I). A liberal invasive treatment strategy was found to be more expensive than exercise advice only after two years of follow-up. Cost-effectiveness results were within the threshold of the Swedish national guidelines regarding willingness to pay (papers II and IV). Both the clinical benefit and the cost-effectiveness of a liberal invasive treatment strategy that were found after two years of follow-up was lost at five years (paper III). In conclusion, invasive revascularization of patients with IC appears to be safe in terms of limb outcome within the first post-procedural year. A liberal invasive treatment strategy was cost-effective compared to exercise alone after two years of follow-up. No clinical benefit, nor cost-effectiveness compared to exercise remained after five years. Future studies should aim at identifying IC subgroups that benefit the most from revascularization and exercise, respectively, in order to enhance the overall patient benefit from available treatment options.
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7. |
- Djerf, Henrik, et al.
(author)
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Low Risk of Procedure Related Major Amputation Following Revascularisation for Intermittent Claudication: A Population Based Study.
- 2020
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In: European journal of vascular and endovascular surgery : the official journal of the European Society for Vascular Surgery. - : Elsevier BV. - 1532-2165. ; 59:5, s. 817-822
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Journal article (peer-reviewed)abstract
- To investigate the risk of procedure-related major amputation attributable to revascularization for intermittent claudication (IC) in a population-based observational cohort study.All patients who underwent open or endovascular lower limb revascularisation for IC in Sweden between 12 May 2008 and 31 December 2012 were identified from the Swedish National Quality Registry for Vascular Surgery (Swedvasc) and data on above ankle amputations were extracted from the National Patient Registry. Any uncertainty regarding amputation level and laterality was resolved by reviewing medical charts. For the final analysis, complete medical records of all patients with IC, having ipsilateral amputation after the revascularisation procedure, were reviewed. Patients wrongly classified as having IC were excluded. Ipsilateral amputations within one year of the revascularisation were defined as procedure related.Altogether, 5 860 patients revascularised for IC were identified of whom 109 were registered to have undergone a post-operative ipsilateral lower limb amputation during a median follow up of 3.9 years (standard deviation 1.5y). Seventeen were duplicate registrations and 51 were patients with chronic limb threatening ischaemia, misclassified as IC in the registry. One patient had not undergone any revascularisation, one was revascularised for a popliteal artery aneurysm, one was revascularised for acute limb ischaemia, one had a minor amputation only, and one patient was not amputated at all. Twenty-seven were amputated more than one year after the procedure. Thus, the major amputation rate within one year of revascularisation for IC was 0.2% (n=9/5 860).Revascularisation for IC in a contemporary setting confers a low but existing risk of procedure related major amputation within the first post-procedural year.
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8. |
- Djerf, Tove, 1989, et al.
(author)
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Solids back-mixing in the transport zone of circulating fluidized bed boilers
- 2022
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In: Chemical Engineering Journal. - : Elsevier BV. - 1385-8947. ; 428
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Journal article (peer-reviewed)abstract
- This work investigates the back-mixing of solids in the transport zone of large-scale circulating fluidized bed (CFB) boilers, with the aims of identifying and evaluating the governing mechanisms and providing a mathematical description based on a solid theoretical background rather than on purely empirical correlations. In addition, transient Direct Numerical Simulation (DNS) modeling is used to identify the mechanism that drives migration of the solids from the dilute up-flow in the core region to the down-flow at the furnace walls. Previously published concentration and pressure profiles are collated and analyzed through modeling of the steady-state mass balance of the dispersed solids in the transport zone. The study shows that solids back-mixing at the furnace wall layers is limited (hence governed) by the core-to-wall layer mass transfer transport mechanism rather than by the lateral movement of solids within the core region. The latter is shown by the 3-dimensional (3D) mass balance model, and the transient DNS modeling indicates that this is due to a turbophoresis mechanism. We also show that the use of Pe-numbers to describe the lateral solids dispersion is not straightforward but rather depends on the unit scale, and that Pe-numbers < 26 are needed to yield the solids back-mixing rates measured in large-scale CFB boilers. Finally, we propose a mathematical expression for the core-to-wall layer mass transfer coefficient derived from a Sherwood number (Sh)-correlation fitted to measured values of the characteristic decay constant that result from the solids back-mixing. This expression shows better agreement with the large-scale measurements than do the expressions given in the literature.
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