Optically-excited excitonic states in semiconductor superlattices

An efficient method for calculation of the exciton states in type-I superlattices is developed and demonstrated. The model, based on the work of Dignam & Sipe [Phys. Rev. B 43,4097 (1991)], includes bound and quasi-continuous two-well exciton eigenstates as a basis in which to expand the superlattice exciton eigenstates. This basis is used to calculate the excitonic absorption spectra for two different type-I superlattices as a function of the applied static field. The results are found to be in very good agreement with the experimental results of Holfeld et. al [Phys. Rev. Lett. 81, 874 (1998)] for the 67A/17A superlattice and with those of Agullo-Rueda et. al [Phys. Rev. B 41, 1676 (1990)] for the 40A/40 A superlattice. On the basis of these results, this method should be ideal for use in the calculation of nonlinear and coherent effects in optically excited semiconductor superlattices

Ibrutinib for Treating Relapsed or Refractory Mantle Cell Lymphoma: An Evidence Review Group Perspective of a NICE Single Technology Appraisal

As part of its Single Technology Appraisal process, the UK National Institute for Health and Care Excellence (NICE) invited the manufacturer of ibrutinib (Janssen) to submit evidence on the clinical effectiveness and cost effectiveness of ibrutinib for the treatment of relapsed or refractory (R/R) mantle cell lymphoma (MCL). The School of Health and Related Research Technology Assessment Group at the University of Sheffield was commissioned to act as the independent Evidence Review Group (ERG). The ERG produced a critical review of the evidence contained within the company’s submission to NICE. The clinical effectiveness evidence for ibrutinib included one randomised controlled trial comparing ibrutinib and temsirolimus and two single-arm studies. The company’s indirect comparison of ibrutinib versus rituximab plus chemotherapy (R-chemo) produced a hazard ratio (HR) for progression-free survival (PFS) of 0.28. The ERG’s random effects network meta-analysis (NMA) indicated that the treatment effect on PFS was highly uncertain (HR 0.27; 95% credible interval (CrI) 0.06–1.26). The company’s Markov model assessed the cost effectiveness of ibrutinib versus R-chemo for the treatment of R/R MCL from the perspective of the National Health Service (NHS) and Personal Social Services over a lifetime horizon. Based on a re-run of the company’s model by the ERG, the incremental cost-effectiveness ratio (ICER) for ibrutinib versus R-chemo [including the company’s original patient access scheme (PAS)] was expected to be £76,014 per quality-adjusted life-year (QALY) gained. The ERG had several concerns regarding the company’s model structure and the evidence used to inform its parameters. The ERG’s preferred analysis, which used the ERG’s NMA and the observed Kaplan–Meier curve for time to ibrutinib discontinuation and excluded long-term disutilities for R-chemo, produced ICERs of £63,340 per QALY gained for the overall R/R MCL population and of £44,711 per QALY gained for patients with one prior treatment. Following an updated PAS and consideration of evidence from a later data-cut of the RAY trial, the appraisal committee concluded that the most plausible ICER for the one prior treatment subgroup was likely to be lower than the company’s estimate of £49,848 per QALY gained. The company’s ICER for the overall R/R MCL population was higher, at £62,650 per QALY gained. The committee recommended ibrutinib as an option for treating R/R MCL in adults only if they have received only one previous line of therapy and the company provides ibrutinib with the discount agreed in the commercial access agreement with NHS England

The Cost Effectiveness of Lisdexamfetamine Dimesylate for the Treatment of Binge Eating Disorder in the USA

BACKGROUND: Lisdexamfetamine dimesylate (LDX) demonstrated efficacy in terms of reduced binge eating days per week in adults with binge eating disorder (BED) in two randomized clinical trials (RCTs). OBJECTIVE: The objective of this study was to evaluate the cost effectiveness of LDX versus no pharmacotherapy (NPT) in adults with BED from a USA healthcare payer’s perspective. STUDY DESIGN AND METHODS: A decision-analytic Markov cohort model was developed using 1-week cycles and a 52-week time horizon. Markov health states were defined based upon the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition criteria of BED. Model parameter estimates were obtained from RCTs, a survey, and literature. The primary outcome was incremental cost-effectiveness ratio (ICER). The analysis assumed a 12-week course of treatment, based upon RCTs’ treatment duration. One-way deterministic and probabilistic sensitivity analyses were conducted to assess the robustness of the results. RESULTS: Patients on LDX therapy gained 0.006 quality-adjusted life years (QALY) compared to patients on the NPT arm, while the average total cost was US$175 higher for LDX therapy. The estimated ICER for LDX compared with NPT was US$27,618 per QALY, which was shown to be cost effective given a willingness-to-pay threshold of US$50,000. CONCLUSIONS: Treatment of BED with LDX showed increase in QALYs at an acceptable cost and is considered to be cost effective at the commonly used willingness-to-pay threshold in the USA. Based on the available evidence, the current model focused on short-term benefits only. There is a need to generate additional scientific evidence supporting long-term benefits of LDX therapy for BED. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s40261-016-0381-3) contains supplementary material, which is available to authorized users

Therapeutic Options for the Prevention and Treatment of Postoperative Nausea and Vomiting: A Pharmacoeconomic Review

Even with the development of the serotonin 5-HT3 receptor antagonists in recent years, postoperative nausea and vomiting (PONV) remains a significant concern for clinicians and patients. For the selection of an appropriate antiemetic strategy for PONV, economic considerations should be taken into account. A literature search covering the period from September 1996 to August 2005 yielded 16 economic evaluations on antiemetics used for the prevention or treatment of PONV. In these studies, a variety of different antiemetic regimens were evaluated, with different doses and timing of administration, in many different populations, for various types of surgery, and in different settings. In addition, there were many differences in the design of these economic evaluations in terms of the extent of the costs considered and the decision rules used when forming conclusions. Therefore, despite the availability of economic evaluations on antiemetics in PONV, it is difficult to draw clear conclusions with such disparate information. In spite of these limitations, key learning can be drawn from these economic evaluations. From studies where a placebo was used as a comparator, we can conclude that there is clinical benefit in using an antiemetic for the prevention of PONV versus no therapy. The dose of the 5-HT3 receptor antagonist seems more important in determining cost effectiveness than the selection of the agent itself, and less expensive agents such as droperidol, dexamethasone and prochlorperazine may also represent cost-effective alternatives to 5-HT3 receptor antagonists. In an additional six studies where a willingness to pay (WTP) to avoid or reduce the incidence of PONV was estimated, the average WTP amounts varied from $US29 to$US117. Many questions remain unanswered about the cost effectiveness of existing antiemetics and their regimens, and little is known about the impact of new agents, such as the neurokinin-1 receptor antagonists, in the control of PONV.Antiemetics, Cost-effectiveness, Nausea, Surgery, Vomiting

Economic Evaluation of Dexmedetomidine Relative to Midazolam for Sedation in the Intensive Care Unit

ABSTRACT Background: Dexmedetomidine is an α2-receptor agonist administered by continuous infusion in the intensive care unit (ICU) for sedation of critically ill patients who are undergoing mechanical ventilation following intubation. Relative to ICU patients receiving midazolam (α2-aminobutyric acid agonist) for sedation, those receiving dexmedetomidine spent less time on ventilation, had fewer episodes of delirium, and had a lower incidence of tachycardia and hypertension. Objective: To assess the economic impact, in a Canadian context, of dexmedetomidine, relative to midazolam, for sedation in the ICU. Methods: This economic evaluation was based on a cost–consequences analysis, from the perspective of the Canadian health care system. The selected time horizon was an ICU stay (maximum 30 days). Clinical data were obtained from a previously published prospective, randomized, double-blind trial comparing dexmedetomidine and midazolam. This evaluation considered the costs of the medications, mechanical ventilation, and delirium episodes, as well as costs associated with adverse events requiring an intervention. All costs were adjusted to 2010 and are reported in Canadian dollars. Results: The average cost of the medication was higher for dexmedetomidine than midazolam ($1929.57 versus$180.10 per patient), but the average costs associated with mechanical ventilation and management of delirium were lower with dexmedetomidine than with midazolam ($2939 versus$4448 for ventilation; $2127 versus$3012 for delirium). The overall cost per patient was lower with dexmedetomidine than with midazolam ($7022 versus$7680). Deterministic sensitivity analysis confirmed the robustness of the difference. Conclusions: The use of dexmedetomidine was, in most contexts, a more favourable strategy than the use of midazolam, in terms of clinical consequences and economic impact. Dexmedetomidine was less expensive than midazolam and was associated with lower occurrence of delirium and shorter duration of mechanical ventilation.RÉSUMÉ Contexte : La dexmédétomidine est un agoniste des récepteurs alpha-2 adrénergiques qu’on administre par perfusion continue à l’unité de soins intensifs (USI) pour la sédation des patients en phase critique, mis sous ventilation artificielle après intubation. Par rapport aux patients de l’USI qui ont reçu du midazolam (un agoniste de l’acide gammaaminobutyrique) comme sédatif, ceux qui ont reçu de la dexmédétomidine sont restés moins longtemps sous ventilation, ont éprouvé moins d’épisodes de délire et ont connu une incidence plus faible de tachycardie et d’hypertension. Objectif : Comparer les coûts de l’emploi de la dexmédétomidine à ceux du midazolam pour la sédation des patients d’une USI dans un context canadien. Méthodes : Une évaluation économique fondée sur une analyse coûts-conséquences a été menée dans le context du système de soins de santé canadien. La période d’évaluation retenue a été un séjour à l’USI d’un maximum de 30 jours. Les données cliniques ont été tirées des résultats publiés d’un essai prospectif, à répartition aléatoire et à double insu comparant la dexmédétomidine et le midazolam. Les coûts pris en compte dans cette évaluation étaient ceux des médicaments, de la ventilation artificielle, des épisodes de délire de même que ceux associés aux événements indésirables nécessitant une intervention. Tous les coûts ont été convertis en dollars de 2010 et sont présentés en dollars canadiens. Résultats : Le coût moyen des médicaments était plus élevé pour la dexmédétomidine que pour le midazolam (1929,57 $contre 180,10$ par patient), mais les coûts moyens associés à la ventilation artificielle et à la prise en charge du délire étaient moins élevés avec la dexmédétomidine qu’avec le midazolam (2939 $contre 4448$ pour la ventilation; 2127 $contre 3012$ pour le délire). Le coût global par patient était inférieur avec la dexmédétomidine qu’avec le midazolam (7022 $contre 7680$). Une analyse de sensibilité déterministe a confirmé la robustesse de cette différence. Conclusions : L’emploi de la dexmédétomidine était dans la plupart des cas une stratégie préférable à l’emploi du midazolam, pour ce qui est des conséquences cliniques et de la résultante financière. La dexmédétomidine s’est révélée moins chère que le midazolam et a été associée à une fréquence moindre de délire et à une durée moindre de la ventilation artificielle