De Novo Cost-Effectiveness Model Framework for Nonalcoholic Steatohepatitis-Modeling Approach and Validation

BACKGROUND

Nonalcoholic steatohepatitis (NASH) is a chronic liver disease associated with hepatic morbidity and mortality and extra-hepatic comorbidities. Published NASH cost-effectiveness models (CEMs) are heterogeneous and consistently omit comorbid conditions that frequently co-exist alongside NASH. We aimed to develop a de novo CEM framework that incorporates extra-hepatic disease states and outcomes alongside hepatic components to enable future estimation of the cost-effectiveness of NASH interventions.

METHODS

Patient-level simulation and cohort-level Markov models were implemented in the same framework. Model inputs included fibrosis progression; late-stage liver disease outcomes; comorbidity outcomes for cardiovascular disease, type 2 diabetes, and obesity; mortality; health-related quality of life; and direct medical costs. The prototype analysis assessed the cost-effectiveness of obeticholic acid versus standard of care from a US payer perspective over a lifetime horizon with costs and effects discounted at 3% per annum. However, the CEM was designed for easy adaptation to other countries, time horizons, and other considerations. Efficacy and adverse event parameters were obtained from the 18-month interim analysis of the REGENERATE trial. Outputs include total and incremental costs, total life years, and quality-adjusted life years.

RESULTS

In this model, total costs, total life years, and quality-adjusted life years were all higher with obeticholic acid compared with standard of care. Cross-validation of this model with the 2016 and 2020 Institute for Clinical and Economic Review models revealed marked differences, mainly driven by mortality inputs, transition probability estimates, and incorporation of the effect of treatment and comorbidities.

CONCLUSION

This is the first CEM in NASH to incorporate the clinical consequences of several comorbidities. The flexible yet standardized framework permits estimation of the cost-effectiveness of NASH interventions in a variety of settings. The model currently includes several assumptions and will be further developed as more relevant data become available.

Identification of an Optimal COVID-19 Booster Allocation Strategy to Minimize Hospital Bed-Days with a Fixed Healthcare Budget

Healthcare decision-makers face difficult decisions regarding COVID-19 booster selection given limited budgets and the need to maximize healthcare gain. A constrained optimization (CO) model was developed to identify booster allocation strategies that minimize bed-days by varying the proportion of the eligible population receiving different boosters, stratified by age, and given limited healthcare expenditure. Three booster options were included: B₁, costing US $1 per dose, B₂, costing US $2, and no booster (NB), costing US $0. B₁ and B₂ were assumed to be 55%/75% effective against mild/moderate COVID-19, respectively, and 90% effective against severe/critical COVID-19. Healthcare expenditure was limited to US$2.10 per person; the minimum expected expense using B_1, B_2, or NB for all. Brazil was the base-case country. The model demonstrated that B₁ for those aged <70 years and B₂ for those ≥70 years were optimal for minimizing bed-days. Compared with NB, bed-days were reduced by 75%, hospital admissions by 68%, and intensive care unit admissions by 90%. Total costs were reduced by 60% with medical resource use reduced by 81%. This illustrates that the CO model can be used by healthcare decision-makers to implement vaccine booster allocation strategies that provide the best healthcare outcomes in a broad range of contexts.

Health Impact and Cost-effectiveness Assessment for the Introduction of Universal Varicella Vaccination in Switzerland

BACKGROUND

Varicella, caused by the varicella-zoster virus, is a highly contagious infectious disease with substantial health and economic burden to society. Universal varicella vaccination (UVV) is not yet recommended by the Swiss National Immunization Program, which instead recommends catch-up immunization for children, adolescents and adults 11-40 years of age who have no reliable history of varicella or are varicella-zoster virus-IgG seronegative. The objective of this study was to perform an assessment of health impact and cost-effectiveness comparing UVV with current practice and recommendations in Switzerland.

METHODS

A dynamic transmission model for varicella was adapted to Switzerland comparing 2 base-case schedules (no infant vaccination and 10% coverage with infant vaccination) to 3 different UVV schedules using quadrivalent (varicella vaccine combined with measles-mumps-rubella) and standalone varicella vaccines administered at different ages. Modeled UVV coverage rates were based on current measles-mumps-rubella coverage of approximately 95% (first dose) and 90% (second dose). Direct medical costs and societal perspectives were considered, with cost and outcomes discounted and calculated over a 50-year time horizon.

RESULTS

UVV would reduce the number of varicella cases by 88%-90%, hospitalizations by 62%-69% and deaths by 75%-77%. UVV would increase direct medical costs by Swiss Franc (CHF) 39-49 (US $43-54) per capita and costs from a societal perspective by CHF 32-40 (US $35-44). Incremental quality-adjusted life-years per capita increased by 0.0012-0.0014. Incremental cost-effectiveness ratios for the UVV schedules versus the base-case were CHF 31,194-35,403 (US $34,452-39,100) per quality-adjusted life-year from the direct medical cost perspective and CHF 25,245-29,552 (US $27,881-32,638) from the societal perspective.

CONCLUSIONS

UVV appears highly effective and cost-effective when compared with current clinical practice and recommendations in Switzerland from both a direct medical costs perspective and societal perspective.

Estimated cost-effectiveness and burden of disease associated with quadrivalent cell-based and egg-based influenza vaccines in Spain

Influenza is a viral respiratory disease that causes significant clinical and economic burden globally. Quadrivalent influenza vaccine (QIV) is frequently used to protect people who have a high-risk of developing influenza complications due to comorbidities. QIV offers protection against influenza A (A/H1N1 and H3N2) and B (B/Victoria, and B/Yamagata) strains. The European Medicines Agency has recently approved a cell-based QIV (QIVc) in people aged over 9 years old. QIVc has been shown to be more effective at preventing influenza than traditional egg-based QIV (QIVe). In this study, we use a health economic model adapted to Spain to assess the costs and outcomes associated with using QIVc instead of QIVe in people aged 9-64 at high-risk of complications. Observed vaccine coverage of 32% in the 9-17 age group, 17% in those aged 18-59, and 22% for ages 60-64 was used in the analysis. In total, 2.5 million people were vaccinated in the simulations. Using QIVc instead of QIVe was associated with 16,221fewer symptomatic cases, 4,522 fewer primary care visits, 1,015 fewer emergency room visits and 88 fewer hospitalizations. From a societal perspective, QIVc was more effective and less expensive compared to QIVe, leading to a cost-saving of €3.4 million. From a public payer perspective, the incremental cost-effectiveness ratio for QIVc vs QIVe was €12,852 per QALY gained. In conclusion, QIVc offers a cost-effective alternative to QIVe and should be considered as an alternative vaccine to QIVe for people aged 9-64 at high-risk of influenza complications in Spain.

The Cost-Effectiveness of Universal Varicella Vaccination in Italy: A Model-Based Assessment of Vaccination Strategies

Background

In 2017, varicella vaccination became mandatory for all children in Italy, based on a two-dose schedule administered at 12–15 months of age and 5 to 6 years of age. Varicella vaccines are available in different formulations (as a single vaccine or as a combination vaccine together with measles, mumps, and rubella) and are made by multiple manufacturers with different effectiveness profiles. This study calculates the cost-effectiveness of a range of varicella vaccination strategies to identify the optimal strategy for Italy.

Methods

A dynamic transmission cost-effectiveness model was applied in Italy to simulate the long-term (50 years) costs and outcomes associated with different varicella vaccination strategies. Five vaccination strategies were evaluated using the model: two doses of two different combination Measles-Mumps-Rubella-Varicella vaccines (either Vaccine A (MSD) [denoted QQVa] or Vaccine B (GSK) [denoted QQVb]); a first dose of a single Varicella vaccine followed by a second dose of a combination vaccine (either Vaccine C (MSD) followed by Vaccine A [denoted MQVa] or Vaccine D (GSK) followed by Vaccine B [denoted MQVb]); or no vaccine at all (NV). The model was adapted for Italy using publicly available Italian data and expert opinion.

Results

Over the 50-year time-horizon, in the absence of universal varicella vaccination, there would be 34.8 million varicella cases, 142 varicella-infection-related deaths, and €23 billion in societal costs. The cost per capita from a societal perspective ranged from €164.55 to €392.18 with NV being the most expensive and QQVa the least expensive. The most effective strategy was QQVa, which resulted in a 66% decrease in varicella cases and 30% reduction in varicella-related deaths compared to NV strategy. QQVa led to a net saving in societal cost around €13 billion compared to NV as the cost of vaccination was more than offset by the savings that resulted from the reduced burden of illness.

Conclusion

Varicella vaccination has a major impact on reducing varicella incidence, prevalence, and societal costs. This analysis supports the policy for universal varicella vaccination in Italy as the NV strategy was the most expensive and resulted in the poorest outcomes. QQVa offers the greatest benefits at the lowest cost and should be considered as a potential priority strategy for Italian population.

A retrospective real-world study of dapagliflozin versus other oral antidiabetic drugs added to metformin in patients with type 2 diabetes

OBJECTIVES

The efficacy of dapagliflozin as add-on therapy to metformin has been assessed in randomized trials. However, its effectiveness has not been assessed in a US real-world setting.

METHODS

Electronic medical record (EMR) data were used to compare clinical outcomes among patients with type 2 diabetes (T2D) treated with dapagliflozin and metformin with or without other oral antidiabetic drugs (D + M ± OAD), versus metformin with at least 1 other OAD (M + OAD). Adult patients with T2D on these regimens from January 01, 2014, to February 28, 2015, were identified in a US EMR database, with the date of first prescription for dapagliflozin (D + M ± OAD) or other OAD (M + OAD) as the index date. Patients were observed for 12 months before the index date (baseline) and 12 months afterward (ie, follow-up). Patients in the M + OAD group were propensity score matched 1:1 to those in the D + M ± OAD group. Outcomes included change in glycated hemoglobin (A1C) level, weight, and systolic and diastolic blood pressures (SBP/DBP) from baseline to follow-up.

RESULTS

A total of 1093 patients receiving M + OAD were matched to 1093 patients receiving D + M ± OAD. Compared with those given M + OAD, patients given D + M ± OAD had a greater reduction in A1C level (mean, -1.0% vs -0.7%; P <.01), greater weight loss (-1.8 kg vs -0.7 kg, P <.01), and greater change in SBP (-3.6 mm Hg vs -0.1 mm Hg, P <.01) and DBP (-2.0 mm Hg vs -0.6 mm Hg, P <.01) from baseline to follow-up.

CONCLUSIONS

In current US clinical practice, patients receiving D + M ± OAD had greater reductions in important clinical outcomes of T2D-A1C level, weight loss, and blood pressure-versus patients receiving M + OAD. This study supports the use of dapagliflozin as add-on therapy to metformin with or without other OADs for patients with T2D.

Cost-effectiveness of dabigatran etexilate for the prevention of stroke and systemic embolism in UK patients with atrial fibrillation

Objective

To assess the cost-effectiveness of dabigatran etexilate, a new oral anticoagulant, versus warfarin and other alternatives for the prevention of stroke and systemic embolism in UK patients with atrial fibrillation (AF).

Methods

A Markov model estimated the cost-effectiveness of dabigatran etexilate versus warfarin, aspirin or no therapy. Two patient cohorts with AF (starting age of <80 and ≥80 years) were considered separately, in line with the UK labelled indication. Modelled outcomes over a lifetime horizon included clinical events, quality-adjusted life years (QALYs), total costs and incremental cost-effectiveness ratios (ICERs).

Results

Patients treated with dabigatran etexilate experienced fewer ischaemic strokes (3.74 dabigatran etexilate vs 3.97 warfarin) and fewer combined intracranial haemorrhages and haemorrhagic strokes (0.43 dabigatran etexilate vs 0.99 warfarin) per 100 patient-years. Larger differences were observed comparing dabigatran etexilate with aspirin or no therapy. For patients initiating treatment at ages <80 and ≥80 years, the ICERs for dabigatran etexilate were £4831 and £7090/QALY gained versus warfarin with a probability of cost-effectiveness at £20 000/QALY gained of 98% and 63%, respectively. For the patient cohort starting treatment at ages <80 years, the ICER versus aspirin was £3457/QALY gained and dabigatran etexilate was dominant (ie, was less costly and more effective) compared with no therapy. These results were robust in sensitivity analyses.

Conclusions

This economic evaluation suggests that the use of dabigatran etexilate as a first-line treatment for the prevention of stroke and systemic embolism is likely to be cost-effective in eligible UK patients with AF.

Economic analyses comparing tiotropium with ipratropium or salmeterol in UK patients with COPD

AIMS

This study presents a cost-effectiveness and budget impact analysis comparing cost and outcomes for UK patients with COPD treated with either tiotropium, ipratropium or salmeterol.

METHODS

A previously-published COPD cost-effectiveness model was adapted for the UK, then used to estimate the cost-effectiveness of tiotropium compared to salmeterol and ipratropium. Additional epidemiological data were used to estimate the budget impact of switching patients from ipratropium or salmeterol to tiotropium.

RESULTS

In England, the estimated annual cost per patient on tiotropium was pound1350, on salmeterol was pound1404, and on ipratropium was pound1427; in Scotland/Wales/Northern Ireland (S/W/NI) these costs were pound1439, pound1565, and pound1631, respectively. Tiotropium patients experienced better quality-adjusted life-years (QALYs) across all comparisons, and this option was therefore dominant compared to salmeterol and ipratropium. The probability of tiotropium being dominant ranged from 72% to 87% across comparisons. At a willingness to pay threshold of pound20,000 per QALY, tiotropium had at least a 97% chance of being cost-effective. The estimated annual saving per primary care trust (PCT) of switching patients from salmeterol and ipratropium to tiotropium in England was pound230,000 and in S/W/NI was pound160,000.

CONCLUSIONS

Tiotropium is a cost-effective alternative to ipratropium and salmeterol, and switching COPD patients from ipratropium and salmeterol to tiotropium could result in considerable cost savings for PCTs along with improvements in quality-of-life.

Cost-effectiveness analyses of natalizumab (Tysabri) compared with other disease-modifying therapies for people with highly active relapsing-remitting multiple sclerosis in the UK

BACKGROUND

Natalizumab (Tysabri) is a new disease-modifying therapy that has been shown to be clinically effective in patients with relapsing-remitting multiple sclerosis (RRMS) and has been licensed for use in patients with highly active RRMS (HARRMS). These patients are those who experience higher relapse rates and faster disability progression than the general RRMS population.

OBJECTIVES

To estimate the cost effectiveness of natalizumab compared with interferon-beta, glatiramer acetate and best supportive care from various UK cost perspectives.

METHODS

A 30-year Markov model was developed, based on previously published models for multiple sclerosis, to estimate transition between disability states and the probability of relapse within disability states. The model was parameterized with data from the UK Multiple Sclerosis (MS) Survey 2005 and data from the AFFIRM study, a 2-year multicentre, randomized, double-blind, placebo-controlled trial of natalizumab in RRMS patients. Additional data were sourced from the literature. A UK societal cost perspective was used in the base case, with additional cost perspectives considered in the sensitivity analysis. The baseline characteristics for the patient group were taken from the patient population in the AFFIRM study (mean age 36 years, mean time since diagnosis 5 years and a mean Kurtzke Extended Disability Status Scale [EDSS] score of 2.5). The model and its parameterization were designed and developed to support a reimbursement application for natalizumab submitted to the UK National Institute for Health and Clinical Excellence (NICE). Efficacies for natalizumab and glatiramer acetate were taken from clinical trial data, and for interferon-beta from a meta-analysis of clinical trial data. Disutilities from adverse events for each comparator were also included in the model. Outcomes and costs were discounted at 3.5% per anum. Costs for interferon-beta and glatiramer acetate were based on published prices (year 2006 values) under the UK Risk Sharing Scheme, and for natalizumab the UK NHS list price was used. Diagnostic, administration and adverse event costs were also included. The incremental cost-effectiveness ratios (ICERs) were calculated for the base case, and a probabilistic sensitivity analysis was performed to assess the probability of cost effectiveness at different willingness-to-pay thresholds.

RESULTS

The ICER for natalizumab compared with interferon-beta was 2300 pound per QALY. Compared with glatiramer acetate, it was 2000 pound per QALY, and compared with best supportive care it was 8200 pound per QALY. From a health and social care cost perspective, the ICERs were 18,700 pound, 20,400 pound and 25,500 per QALY, respectively. At a willingness-to-pay threshold of 30,000 pound per QALY, the probability of natalizumab being cost effective against any comparator from a societal perspective was >89%.

CONCLUSION

If UK society is willing to pay more than 8200 pound per QALY, or Health and Social Services are willing to pay more than 26,000 pound per QALY, this analysis suggests that natalizumab is likely to be a cost-effective treatment for all patients with HARRMS.

Real-time epidemic forecasting for pandemic influenza

The ongoing worldwide spread of the H5N1 influenza virus in birds has increased concerns of a new human influenza pandemic and a number of surveillance initiatives are planned, or are in place, to monitor the impact of a pandemic in near real-time. Using epidemiological data collected during the early stages of an outbreak, we show how the timing of the maximum prevalence of the pandemic wave, along with its amplitude and duration, might be predicted by fitting a mass-action epidemic model to the surveillance data by standard regression analysis. This method is validated by applying the model to routine data collected in the United Kingdom during the different waves of the previous three pandemics. The success of the method in forecasting historical prevalence suggests that such outbreaks conform reasonably well to the theoretical model, a factor which may be exploited in a future pandemic to update ongoing planning and response.

Thermal pretreatment of the solid fraction of manure: impact on the biogas reactor performance and microbial community

Application of thermal treatment at 100-140 degrees C as a pretreatment method prior to anaerobic digestion of a mixture of cattle and swine manure was investigated. In a batch test, biogasification of manure with thermally pretreated solid fraction proceeded faster and resulted in the increase of methane yield. The performances of two thermophilic continuously stirred tank reactors (CSTR) treating manure with solid fraction pretreated for 40 minutes at 140 degrees C and non-treated manure were compared. The digester fed with the thermally pretreated manure had a higher methane productivity and an improved removal of the volatile solids (VS). The properties of microbial communities of both reactors were analysed. The specific methanogenic activity (SMA) test showed that both biomasses had significant activity towards hydrogen and formate, while the activity with the VFA - acetate, propionate and butyrate - was low. The kinetic parameters of the VFA conversion revealed a reduced affinity of the microbial community from the CSTR fed with thermally pre-treated manure for acetate, propionate and butyrate. The bacterial and archaeal populations identified by t-RLFP analysis of 16S rRNA genes were found to be identical in both systems. However, a change in the abundance of the species present was detected.

Transmission potential of smallpox in contemporary populations

Despite eradication, smallpox still presents a risk to public health whilst laboratory stocks of virus remain. One factor crucial to any assessment of this risk is R0, the average number of secondary cases infected by each primary case. However, recently applied estimates have varied too widely (R0 from 1.5 to >20) to be of practical use, and often appear to disregard contingent factors such as socio-economic conditions and herd immunity. Here we use epidemic modelling to show a more consistent derivation of R0. In isolated pre-twentieth century populations with negligible herd immunity, the numbers of cases initially rose exponentially, with an R0 between 3.5 and 6. Before outbreak controls were applied, smallpox also demonstrated similar levels of transmission in 30 sporadic outbreaks in twentieth century Europe, taking into account pre-existing vaccination levels (about 50%) and the role of hospitals in doubling early transmission. Should smallpox recur, such estimates of transmission potential (R0 from 3.5 to 6) predict a reasonably rapid epidemic rise before the implementation of public health interventions, because little residual herd immunity exists now that vaccination has ceased.

Nucleoli of cultured human lymphocytes. II. Nuceolar fusion and its relation to acrocentric association

Nucleolar fusion and nucleolus formation occurred simultaneously, immediately after mitosis, in cultured human lymphocytes. Evidence is presented that in late telophase and post-telophase, the individual nucleolar organising site includes two components, represented in post-telophase by the nucleolus and its attached process; that fusion can be either directly between the nucleoli or via the processes; and that the latter type of fusion persists into metaphase as acrocentric associations, whilst the former is lost.