State-transition modeling: a report of the ISPOR-SMDM Modeling Good Research Practices Task Force--3

Cost-effectiveness of apixaban versus low molecular weight heparin/vitamin k antagonist for the treatment of venous thromboembolism and the prevention of recurrences

BACKGROUND

Prior analyses beyond clinical trials are yet to evaluate the projected lifetime benefit of apixaban treatment compared to low-molecular-weight heparin (LMWH)/vitamin K antagonist (VKA) for treatment of venous thromboembolism (VTE) and prevention of recurrences. The objective of this study is to assess the cost-effectiveness of initial plus extended treatment with apixaban versus LMWH/VKA for either initial treatment only or initial plus extended treatment.

METHODS

A Markov cohort model was developed to evaluate the lifetime clinical and economic impact of treatment of VTE and prevention of recurrences with apixaban (starting at 10 mg BID for 1 week, then 5 mg BID for 6 months, then 2.5 mg BID for an additional 12 months) versus LMWH/VKA for 6 months and either no further treatment or extended treatment with VKA for an additional 12 months. Clinical event rates to inform the model were taken from the AMPLIFY and AMPLIFY-EXT trials and a network meta-analysis. Background mortality rates, costs, and utilities were obtained from published sources. The analysis was conducted from the perspective of the United Kingdom National Health Service. The evaluated outcomes included the number of events avoided in a 1000-patient cohort, total costs, life-years, quality-adjusted life-years (QALYs), and cost per QALY gained.

RESULTS

Initial plus extended treatment with apixaban was superior to both treatment durations of LMWH/VKA in reducing the number of bleeding events, and was superior to initial LMWH/VKA for 6 months followed by no therapy, in reducing VTE recurrences. Apixaban treatment was cost-effective compared to 6-month treatment with LMWH/VKA at an incremental cost-effectiveness ratio (ICER) of £6692 per QALY. When initial LMWH/VKA was followed by further VKA therapy for an additional 12 months (i.e., total treatment duration of 18 months), apixaban was cost-effective at an ICER of £8528 per QALY gained. Sensitivity analysis suggested these findings were robust over a wide range of inputs and scenarios for the model.

CONCLUSIONS

In the UK, initial plus extended treatment with apixaban for treatment of VTE and prevention of recurrences appears to be economical and a clinically effective alternative to LMWH/VKA, whether used for initial or initial plus extended treatment.

Cost-effectiveness of In-Home Cognitive Behavioral Therapy for low-income depressed mothers participating in early childhood prevention programs

BACKGROUND

To determine the cost-effectiveness of In-Home Cognitive Behavioral Therapy (IH-CBT) for low-income mothers enrolled in a home visiting program.

METHODS

A cost-utility analysis was conducted using results from a clinical trial of IH-CBT and standard of care for depression derived from the literature. A probabilistic, patient-level Markov model was developed to determine Quality Adjusted Life Years (QALYs). Costs were determined using the Medical Expenditure Panel Survey. A three-year time horizon and payer perspective were used. Sensitivity analyses were employed to determine robustness of the model.

RESULTS

IH-CBT was cost-effective relative to standard of care. IH-CBT was expected to be cost-effective at a three-year time horizon 99.5%, 99.7%, and 99.9% of the time for willingness-to-pay thresholds of US$25,000, US$50,000, and US$100,000, respectively. Patterns were upheld at one-year and five-year time horizons. Over the three-year time horizon, mothers receiving IH-CBT were expected to have 345.6 fewer days of depression relative to those receiving standard home visiting and treatment in the community.

CONCLUSIONS

IH-CBT is a more cost-effective treatment for low-income, depressed mothers than current standards of practice. These findings add to the growing literature demonstrating the cost-effectiveness of CBT for depression, and expand it to cover new mothers. From a payer perspective, IH-CBT is a sound option for treatment of depressed, low-income mothers. Limitations include a restricted time horizon and estimating of standard of care costs.

Cost-Effectiveness Analysis of Second-Line Chemotherapy Agents for Advanced Gastric Cancer

STUDY OBJECTIVE

Gastric cancer is the fifth most common malignancy and second leading cause of cancer-related mortality. Chemotherapy options for patients who fail first-line treatment are limited. Thus the objective of this study was to assess the cost-effectiveness of second-line treatment options for patients with advanced or metastatic gastric cancer.

DESIGN

Cost-effectiveness analysis using a Markov model to compare the cost-effectiveness of six possible second-line treatment options for patients with advanced gastric cancer who have failed previous chemotherapy: irinotecan, docetaxel, paclitaxel, ramucirumab, paclitaxel plus ramucirumab, and palliative care.

MEASUREMENTS AND MAIN RESULTS

The model was performed from a third-party payer's perspective to compare lifetime costs and health benefits associated with studied second-line therapies. Costs included only relevant direct medical costs. The model assumed chemotherapy cycle lengths of 30 days and a maximum number of 24 cycles. Systematic review of literature was performed to identify clinical data sources and utility and cost data. Quality-adjusted life years (QALYs) and incremental cost-effectiveness ratios (ICERs) were calculated. The primary outcome measure for this analysis was the ICER between different therapies, where the incremental cost was divided by the number of QALYs saved. The ICER was compared with a willingness-to-pay (WTP) threshold that was set at $50,000/QALY gained, and an exploratory analysis using $160,000/QALY gained was also used. The model's robustness was tested by using 1-way sensitivity analyses and a 10,000 Monte Carlo simulation probabilistic sensitivity analysis (PSA). Irinotecan had the lowest lifetime cost and was associated with a QALY gain of 0.35 year. Docetaxel, ramucirumab alone, and palliative care were dominated strategies. Paclitaxel and the combination of paclitaxel plus ramucirumab led to higher QALYs gained, at an incremental cost of $86,815 and $1,056,125 per QALY gained, respectively. Based on our prespecified WTP threshold, our base case analysis demonstrated that irinotecan alone is the most cost-effective regimen, and both paclitaxel alone and the combination of paclitaxel and ramucirumab were not cost-effective (ICER more than $50,000). Both 1-way sensitivity analyses and PSA demonstrated the model's robustness. PSA illustrated that paclitaxel plus ramucirumab was extremely unlikely to be cost-effective at a WTP threshold less than $400,000/QALY gained.

CONCLUSION

Irinotecan alone appears to be the most cost-effective second-line regimen for patients with gastric cancer. Paclitaxel may be cost-effective if the WTP threshold was set at $160,000/QALY gained.

Cost Effectiveness of Screening Colonoscopy Depends on Adequate Bowel Preparation Rates - A Modeling Study

Background

Inadequate bowel preparation during screening colonoscopy necessitates repeating colonoscopy. Studies suggest inadequate bowel preparation rates of 20–60%. This increases the cost of colonoscopy for our society.

Aim

The aim of this study is to determine the impact of inadequate bowel preparation rate on the cost effectiveness of colonoscopy compared to other screening strategies for colorectal cancer (CRC).

Methods

A microsimulation model of CRC screening strategies for the general population at average risk for CRC. The strategies include fecal immunochemistry test (FIT) every year, colonoscopy every ten years, sigmoidoscopy every five years, or stool DNA test every 3 years. The screening could be performed at private practice offices, outpatient hospitals, and ambulatory surgical centers.

Results

At the current assumed inadequate bowel preparation rate of 25%, the cost of colonoscopy as a screening strategy is above society’s willingness to pay (<$50,000/QALY). Threshold analysis demonstrated that an inadequate bowel preparation rate of 13% or less is necessary before colonoscopy is considered more cost effective than FIT. At inadequate bowel preparation rates of 25%, colonoscopy is still more cost effective compared to sigmoidoscopy and stool DNA test. Sensitivity analysis of all inputs adjusted by ±10% showed incremental cost effectiveness ratio values were influenced most by the specificity, adherence, and sensitivity of FIT and colonoscopy.

Conclusions

Screening colonoscopy is not a cost effective strategy when compared with fecal immunochemical test, as long as the inadequate bowel preparation rate is greater than 13%.

Quantifying the Transition from Active Surveillance to Watchful Waiting Among Men with Very Low-risk Prostate Cancer

BACKGROUND

Active surveillance (AS) is commonly used for men with low-risk prostate cancer (PCa). When life expectancy becomes too short for curative treatment to be beneficial, a change from AS to watchful waiting (WW) follows. Little is known about this change since it is rarely documented in medical records.

OBJECTIVE

To model transition from AS to WW and how this is affected by age and comorbidity among men with very low-risk PCa.

DESIGN, SETTING, AND PARTICIPANTS

National population-based healthcare registers were used for analysis.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Using data on PCa characteristics, age, and comorbidity, a state transition model was created to estimate the probability of changes between predefined treatments to estimate transition from AS to WW.

RESULTS AND LIMITATIONS

Our estimates indicate that 48% of men with very low-risk PCa starting AS eventually changed to WW over a life course. This proportion increased with age at time of AS initiation. Within 10 yr from start of AS, 10% of men aged 55 yr and 50% of men aged 70 yr with no comorbidity at initiation changed to WW. Our prevalence simulation suggests that the number of men on WW who were previously on AS will eventually stabilise after 30 yr. A limitation is the limited information from clinical follow-up visits (eg, repeat biopsies).

CONCLUSIONS

We estimated that changes from AS to WW become common among men with very low-risk PCa who are elderly. This potential change to WW should be discussed with men starting on AS. Moreover, our estimates may help in planning health care resources allocated to men on AS, as the transition to WW is associated with lower demands on outpatient resources.

PATIENT SUMMARY

Changes from active surveillance to watchful waiting will become more common among men with very low-risk prostate cancer. These observations suggest that patients need to be informed about this potential change before they start on active surveillance.

Modeling the Effects of E-cigarettes on Smoking Behavior: Implications for Future Adult Smoking Prevalence

BACKGROUND

Electronic cigarette (e-cigarette) use has increased rapidly in recent years. Given the unknown effects of e-cigarette use on cigarette smoking behaviors, e-cigarette regulation has become the subject of considerable controversy. In the absence of longitudinal data documenting the long-term effects of e-cigarette use on smoking behavior and population smoking outcomes, computational models can guide future empirical research and provide insights into the possible effects of e-cigarette use on smoking prevalence over time.

METHODS

Agent-based model examining hypothetical scenarios of e-cigarette use by smoking status and e-cigarette effects on smoking initiation and smoking cessation.

RESULTS

If e-cigarettes increase individual-level smoking cessation probabilities by 20%, the model estimates a 6% reduction in smoking prevalence by 2060 compared with baseline model (no effects) outcomes. In contrast, e-cigarette use prevalence among never smokers would have to rise dramatically from current estimates, with e-cigarettes increasing smoking initiation by more than 200% relative to baseline model estimates to achieve a corresponding 6% increase in smoking prevalence by 2060.

CONCLUSIONS

Based on current knowledge of the patterns of e-cigarette use by smoking status and the heavy concentration of e-cigarette use among current smokers, the simulated effects of e-cigarettes on smoking cessation generate substantially larger changes to smoking prevalence compared with their effects on smoking initiation.

Public health economic evaluation of different European Union-level policy options aimed at reducing population dietary trans fat intake

BACKGROUND

The adverse relation between dietary trans fatty acid (TFA) intake and coronary artery disease risk is well established. Many countries in the European Union (EU) and worldwide have implemented different policies to reduce the TFA intake of their populations.

OBJECTIVE

The aim of this study was to assess the added value of EU-level action by estimating the cost-effectiveness of 3 possible EU-level policy measures to reduce population dietary TFA intake. This was calculated against a reference situation of not implementing any EU-level policy (i.e., by assuming only national or self-regulatory measures).

DESIGN

We developed a mathematical model to compare different policy options at the EU level: 1) to do nothing beyond the current state (reference situation), 2) to impose mandatory TFA labeling of prepackaged foods, 3) to seek voluntary agreements toward further reducing industrially produced TFA (iTFA) content in foods, and 4) to impose a legislative limit for iTFA content in foods.

RESULTS

The model indicated that to impose an EU-level legal limit or to make voluntary agreements may, over the course of a lifetime (85 y), avoid the loss of 3.73 and 2.19 million disability-adjusted life-years (DALYs), respectively, and save >51 and 23 billion euros when compared with the reference situation. Implementing mandatory TFA labeling can also avoid the loss of 0.98 million DALYs, but this option incurs more costs than it saves compared with the reference option.

CONCLUSIONS

The model indicates that there is added value of an EU-level action, either via a legal limit or through voluntary agreements, with the legal limit option producing the highest additional health benefits. Introducing mandatory TFA labeling for the EU common market may provide some additional health benefits; however, this would likely not be a cost-effective strategy.

Automated imaging technologies for the diagnosis of glaucoma: a comparative diagnostic study for the evaluation of the diagnostic accuracy, performance as triage tests and cost-effectiveness (GATE study)

BACKGROUND

Many glaucoma referrals from the community to hospital eye services are unnecessary. Imaging technologies can potentially be useful to triage this population.

OBJECTIVES

To assess the diagnostic performance and cost-effectiveness of imaging technologies as triage tests for identifying people with glaucoma.

DESIGN

Within-patient comparative diagnostic accuracy study. Markov economic model comparing the cost-effectiveness of a triage test with usual care.

SETTING

Secondary care.

PARTICIPANTS

Adults referred from the community to hospital eye services for possible glaucoma.

INTERVENTIONS

Heidelberg Retinal Tomography (HRT), including two diagnostic algorithms, glaucoma probability score (HRT-GPS) and Moorfields regression analysis (HRT-MRA); scanning laser polarimetry [glaucoma diagnostics (GDx)]; and optical coherence tomography (OCT). The reference standard was clinical examination by a consultant ophthalmologist with glaucoma expertise including visual field testing and intraocular pressure (IOP) measurement.

MAIN OUTCOME MEASURES

(1) Diagnostic performance of imaging, using data from the eye with most severe disease. (2) Composite triage test performance (imaging test, IOP measurement and visual acuity measurement), using data from both eyes, in correctly identifying clinical management decisions, that is 'discharge' or 'do not discharge'. Outcome measures were sensitivity, specificity and incremental cost per quality-adjusted life-year (QALY).

RESULTS

Data from 943 of 955 participants were included in the analysis. The average age was 60.5 years (standard deviation 13.8 years) and 51.1% were females. Glaucoma was diagnosed by the clinician in at least one eye in 16.8% of participants; 37.9% of participants were discharged after the first visit. Regarding diagnosing glaucoma, HRT-MRA had the highest sensitivity [87.0%, 95% confidence interval (CI) 80.2% to 92.1%] but the lowest specificity (63.9%, 95% CI 60.2% to 67.4%) and GDx had the lowest sensitivity (35.1%, 95% CI 27.0% to 43.8%) but the highest specificity (97.2%, 95% CI 95.6% to 98.3%). HRT-GPS had sensitivity of 81.5% (95% CI 73.9% to 87.6%) and specificity of 67.7% (95% CI 64.2% to 71.2%) and OCT had sensitivity of 76.9% (95% CI 69.2% to 83.4%) and specificity of 78.5% (95% CI 75.4% to 81.4%). Regarding triage accuracy, triage using HRT-GPS had the highest sensitivity (86.0%, 95% CI 82.8% to 88.7%) but the lowest specificity (39.1%, 95% CI 34.0% to 44.5%), GDx had the lowest sensitivity (64.7%, 95% CI 60.7% to 68.7%) but the highest specificity (53.6%, 95% CI 48.2% to 58.9%). Introducing a composite triage station into the referral pathway to identify appropriate referrals was cost-effective. All triage strategies resulted in a cost reduction compared with standard care (consultant-led diagnosis) but with an associated reduction in effectiveness. GDx was the least costly and least effective strategy. OCT and HRT-GPS were not cost-effective. Compared with GDx, the cost per QALY gained for HRT-MRA is £22,904. The cost per QALY gained with current practice is £156,985 compared with HRT-MRA. Large savings could be made by implementing HRT-MRA but some benefit to patients will be forgone. The results were sensitive to the triage costs.

CONCLUSIONS

Automated imaging can be effective to aid glaucoma diagnosis among individuals referred from the community to hospital eye services. A model of care using a triage composite test appears to be cost-effective.

FUTURE WORK

There are uncertainties about glaucoma progression under routine care and the cost of providing health care. The acceptability of implementing a triage test needs to be explored.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Methods to construct a step-by-step beginner's guide to decision analytic cost-effectiveness modeling

BACKGROUND

Although guidance on good research practice in health economic modeling is widely available, there is still a need for a simpler instructive resource which could guide a beginner modeler alongside modeling for the first time.

AIM

To develop a beginner's guide to be used as a handheld guide contemporaneous to the model development process.

METHODS

A systematic review of best practice guidelines was used to construct a framework of steps undertaken during the model development process. Focused methods review supplemented this framework. Consensus was obtained among a group of model developers to review and finalize the content of the preliminary beginner's guide. The final beginner's guide was used to develop cost-effectiveness models.

RESULTS

Thirty-two best practice guidelines were data extracted, synthesized, and critically evaluated to identify steps for model development, which formed a framework for the beginner's guide. Within five phases of model development, eight broad submethods were identified and 19 methodological reviews were conducted to develop the content of the draft beginner's guide. Two rounds of consensus agreement were undertaken to reach agreement on the final beginner's guide. To assess fitness for purpose (ease of use and completeness), models were developed independently and by the researcher using the beginner's guide.

CONCLUSION

A combination of systematic review, methods reviews, consensus agreement, and validation was used to construct a step-by-step beginner's guide for developing decision analytical cost-effectiveness models. The final beginner's guide is a step-by-step resource to accompany the model development process from understanding the problem to be modeled, model conceptualization, model implementation, and model checking through to reporting of the model results.

Effective but costly: How to tackle difficult trade-offs in evaluating health improving technologies in liver diseases

In the current context of rising health care costs and decreasing sustainability, it is becoming increasingly common to resort to decision analytical modeling and health economics evaluations. Decision analytic models are analytical tools that help decision makers to select the best choice between alternative health care interventions, taking into consideration the complexity of the disease, the socioeconomic context, and the relevant differences in outcomes. We present a brief overview of the use of decision analytical models in health economic evaluations and their applications in the area of liver diseases. The aim is to provide the reader with the basic elements to evaluate health economic analysis reports and to discuss some limitations of the current approaches, as highlighted by the case of the therapy of chronic hepatitis C. To serve its purpose, health economics evaluations must be able to do justice to medical innovation and the market while protecting patients and society and promoting fair access to treatment and its economic sustainability.

CONCLUSION

New approaches and methods able to include variables such as prevalence of the disease, budget impact, and sustainability into the cost-effectiveness analysis are needed to reach this goal. (Hepatology 2016;64:1331-1342).

Models of care for the delivery of secondary fracture prevention after hip fracture: a health service cost, clinical outcomes and cost-effectiveness study within a region of England

Background

Professional bodies have produced comprehensive guidance about the management of hip fracture. They recommend orthogeriatric services focusing on achieving optimal recovery, and fracture liaison services (FLSs) focusing on secondary fracture prevention. Despite such guidelines being in place, there is significant variation in how services are structured and organised between hospitals.

Objectives

To establish the clinical effectiveness and cost-effectiveness of changes to the delivery of secondary fracture prevention services, and to identify barriers and facilitators to changes.

Design

A service evaluation to identify each hospital’s current models of care and changes in service delivery. A qualitative study to identify barriers and facilitators to change. Health economics analysis to establish NHS costs and cost-effectiveness. A natural experimental study to determine clinical effectiveness of changes to a hospital’s model of care.

Setting

Eleven acute hospitals in a region of England.

Participants

Qualitative study – 43 health professionals working in fracture prevention services in secondary care.

Interventions

Changes made to secondary fracture prevention services at each hospital between 2003 and 2012.

Main outcome measures

The primary outcome is secondary hip fracture. Secondary outcomes include mortality, non-hip fragility fracture and the overall rate of hip fracture.

Data sources

Clinical effectiveness/cost-effectiveness analyses – primary hip fracture patients identified from (1) Hospital Episode Statistics (2003–13,n = 33,152); and (2) Clinical Practice Research Datalink (1999–2013,n = 11,243).

Results

Service evaluation – there was significant variation in the organisation of secondary fracture prevention services, including staffing levels, type of service model (consultant vs. nurse led) and underlying processes. Qualitative – fracture prevention co-ordinators gave multidisciplinary health professionals capacity to work together, but communication with general practitioners was challenging. The intervention was easily integrated into practice but some participants felt that implementation was undermined by under-resourced services. Making business cases for a service was particularly challenging. Natural experiment – the impact of introducing an orthogeriatrician on 30-day and 1-year mortality was hazard ratio (HR) 0.73 [95% confidence interval (CI) 0.65 to 0.82] and HR 0.81 (95% CI 0.75 to 0.87), respectively. Thirty-day and 1-year mortality were likewise reduced following the introduction or expansion of a FLS: HR 0.80 (95% CI 0.71 to 0.91) and HR 0.84 (95% CI 0.77 to 0.93), respectively. There was no significant impact on time to secondary hip fracture. Health economics – the annual cost in the year of hip fracture was estimated at £10,964 (95% CI £10,767 to £11,161) higher than the previous year. The annual cost associated with all incident hip fractures in the UK among those aged ≥ 50 years (n = 79,243) was estimated at £1215M. At a £30,000 per quality-adjusted life-year threshold, the most cost-effective model was introducing an orthogeriatrician.

Conclusion

In hip fracture patients, orthogeriatrician and nurse-led FLS models are associated with reductions in mortality rates and are cost-effective, the orthogeriatrician model being the most cost-effective. There was no evidence for a reduction in second hip fracture. Qualitative data suggest that weaknesses lie in treatment adherence/monitoring, a possible reason for the lack of effectiveness on second hip fracture outcome. The effectiveness on non-hip fracture outcomes remains unanswered.

Future work

Reliable estimates of health state utility values for patients with hip and non-hip fractures are required to reduce uncertainty in health economic models. A clinical trial is needed to assess the clinical effectiveness and cost-effectiveness of a FLS for non-hip fracture patients.

Funding

The National Institute for Health Research (NIHR) Health Services and Delivery Research programme and the NIHR Musculoskeletal Biomedical Research Unit, University of Oxford.

Cost-effectiveness of drug-eluting stents versus bare-metal stents in patients undergoing percutaneous coronary intervention

OBJECTIVE

To determine the cost-effectiveness of drug-eluting stents (DES) compared with bare-metal stents (BMS) in patients requiring a percutaneous coronary intervention in France, using a recent meta-analysis including second-generation DES.

METHODS

A cost-effectiveness analysis was performed in the French National Health Insurance setting. Effectiveness settings were taken from a meta-analysis of 117 762 patient-years with 76 randomised trials. The main effectiveness criterion was major cardiac event-free survival. Effectiveness and costs were modelled over a 5-year horizon using a three-state Markov model. Incremental cost-effectiveness ratios and a cost-effectiveness acceptability curve were calculated for a range of thresholds for willingness to pay per year without major cardiac event gain. Deterministic and probabilistic sensitivity analyses were performed.

RESULTS

Base case results demonstrated that DES are dominant over BMS, with an increase in event-free survival and a cost-reduction of €184, primarily due to a diminution of second revascularisations, and an absence of myocardial infarction and stent thrombosis. These results are robust for uncertainty on one-way deterministic and probabilistic sensitivity analyses. Using a cost-effectiveness threshold of €7000 per major cardiac event-free year gained, DES has a >95% probability of being cost-effective versus BMS.

CONCLUSIONS

Following DES price decrease, new-generation DES development and taking into account recent meta-analyses results, the DES can now be considered cost-effective regardless of selective indication in France, according to European recommendations.

GetReal in mathematical modelling: a review of studies predicting drug effectiveness in the real world

The performance of a drug in a clinical trial setting often does not reflect its effect in daily clinical practice. In this third of three reviews, we examine the applications that have been used in the literature to predict real‐world effectiveness from randomized controlled trial efficacy data. We searched MEDLINE, EMBASE from inception to March 2014, the Cochrane Methodology Register, and websites of key journals and organisations and reference lists. We extracted data on the type of model and predictions, data sources, validation and sensitivity analyses, disease area and software. We identified 12 articles in which four approaches were used: multi‐state models, discrete event simulation models, physiology‐based models and survival and generalized linear models. Studies predicted outcomes over longer time periods in different patient populations, including patients with lower levels of adherence or persistence to treatment or examined doses not tested in trials. Eight studies included individual patient data. Seven examined cardiovascular and metabolic diseases and three neurological conditions. Most studies included sensitivity analyses, but external validation was performed in only three studies. We conclude that mathematical modelling to predict real‐world effectiveness of drug interventions is not widely used at present and not well validated. © 2016 The Authors Research Synthesis Methods Published by John Wiley & Sons Ltd.

Deep Brain Stimulation for Parkinson's Disease with Early Motor Complications: A UK Cost-Effectiveness Analysis

BACKGROUND

Parkinson's disease (PD) is a debilitating illness associated with considerable impairment of quality of life and substantial costs to health care systems. Deep brain stimulation (DBS) is an established surgical treatment option for some patients with advanced PD. The EARLYSTIM trial has recently demonstrated its clinical benefit also in patients with early motor complications. We sought to evaluate the cost-effectiveness of DBS, compared to best medical therapy (BMT), among PD patients with early onset of motor complications, from a United Kingdom (UK) payer perspective.

METHODS

We developed a Markov model to represent the progression of PD as rated using the Unified Parkinson's Disease Rating Scale (UPDRS) over time in patients with early PD. Evidence sources were a systematic review of clinical evidence; data from the EARLYSTIM study; and a UK Clinical Practice Research Datalink (CPRD) dataset including DBS patients. A mapping algorithm was developed to generate utility values based on UPDRS data for each intervention. The cost-effectiveness was expressed as the incremental cost per quality-adjusted life-year (QALY). One-way and probabilistic sensitivity analyses were undertaken to explore the effect of parameter uncertainty.

RESULTS

Over a 15-year time horizon, DBS was predicted to lead to additional mean cost per patient of £26,799 compared with BMT (£73,077/patient versus £46,278/patient) and an additional mean 1.35 QALYs (6.69 QALYs versus 5.35 QALYs), resulting in an incremental cost-effectiveness ratio of £19,887 per QALY gained with a 99% probability of DBS being cost-effective at a threshold of £30,000/QALY. One-way sensitivity analyses suggested that the results were not significantly impacted by plausible changes in the input parameter values.

CONCLUSION

These results indicate that DBS is a cost-effective intervention in PD patients with early motor complications when compared with existing interventions, offering additional health benefits at acceptable incremental cost. This supports the extended use of DBS among patients with early onset of motor complications.

Development of an enhanced health-economic model and cost-effectiveness analysis of tiotropium + olodaterol Respimat® fixed-dose combination for chronic obstructive pulmonary disease patients in Italy

BACKGROUND

The objective of this study was to compare the cost-effectiveness of the fixed-dose combination (FDC) of tiotropium + olodaterol Respimat(®) FDC with tiotropium alone for patients with chronic obstructive pulmonary disease (COPD) in the Italian health care setting using a newly developed patient-level Markov model that reflects the current understanding of the disease.

METHODS

While previously published models have largely been based around a cohort approach using a Markov structure and GOLD stage stratification, an individual-level Markov approach was selected for the new model. Using patient-level data from the twin TOnado trials assessing Tiotropium + olodaterol Respimat(®) FDC versus tiotropium, outcomes were modelled based on the trough forced expiratory volume (tFEV1) of over 1000 patients in each treatment arm, tracked individually at trial visits through the 52-week trial period, and after the trial period it was assumed to decline at a constant rate based on disease stage. Exacerbation risk was estimated based on a random-effects logistic regression analysis of exacerbations in UPLIFT. Mortality by age and disease stage was estimated from an analysis of TIOSPIR trial data. Cost of bronchodilators and other medications, routine management, and costs of treatment for moderate and severe exacerbations for the Italian setting were included. A cost-effectiveness analysis was conducted over a 15-year time horizon from the perspective of the Italian National Health Service.

RESULTS

Aggregating total costs and quality-adjusted life years (QALYs) for each treatment cohort over 15 years and comparing tiotropium + olodaterol Respimat(®) FDC with tiotropium alone, resulted in mean incremental costs per patient of €1167 and an incremental cost-effectiveness ratio (ICER) of €7518 per additional QALY with tiotropium + olodaterol Respimat(®) FDC. The lung function outcomes observed for tiotropium + olodaterol Respimat(®) FDC in TOnado drove the results in terms of slightly higher mean life-years (12.24 versus 12.07) exacerbation-free months (11.36 versus 11.32) per patient and slightly fewer moderate and severe exacerbations per patient-year (0.411 versus 0.415; 0.21 versus 0.24) versus tiotropium. Probabilistic sensitivity analyses showed tiotropium + olodaterol Respimat(®) FDC to be the more cost-effective treatment in 95.2% and 98.4% of 500 simulations at thresholds of €20,000 and €30,000 per QALY respectively.

CONCLUSION

Tiotropium + olodaterol Respimat(®) FDC is a cost-effective bronchodilator in the maintenance treatment of COPD for the Italian health care system.

Cost-Effectiveness Analysis of Using Loss of Heterozygosity to Manage Premalignant Oral Dysplasia in British Columbia, Canada

BACKGROUND

Management of low-grade oral dysplasias (LGDs) is complicated, as only a small percentage of lesions will progress to invasive disease. The current standard of care requires patients to undergo regular monitoring of their lesions, with intervention occurring as a response to meaningful clinical changes. Recent improvements in molecular technologies and understanding of the biology of LGDs may allow clinicians to manage lesions based on their genome-guided risk.

METHODS

We used a decision-analytic Markov model to estimate the cost-effectiveness of risk-stratified care using a genomic assay. In the experimental arm, patients with LGDs were managed according to their risk profile using the assay, with low- and intermediate-risk patients given longer screening intervals and high-risk patients immediately treated with surgery. Patients in the comparator arm had standard care (biannual follow-up appointments at an oral cancer clinic). Incremental costs and outcomes in life-years gained (LYG) and quality-adjusted life-years (QALY) were calculated based on the results in each arm.

RESULTS

The mean cost of assay-guided management was $8,123 (95% confidence interval [CI] $2,973 to $23,062 in 2013 Canadian dollars) less than the cost of standard care. This difference was driven largely by reductions in resource use among people who did not develop cancer. Mean incremental effectiveness was 0.18 LYG (95% CI 0.08 to 0.39) or 0.64 QALY (95% CI 0.46 to 0.89). Sensitivity analysis suggests that these findings are robust to both expected and extreme variation in all parameter values.

CONCLUSION

Use of the assay-guided management strategy costs less and is more effective than standard management of LGDs.

IMPLICATIONS FOR PRACTICE

The findings of this study strongly suggest that the use of a risk-stratification method such as a genomic assay can result in improved quality-adjusted survival outcomes for patients with low-grade oral dysplasia (LGD). The use of such an assay in this study provides "precision medicine," allowing for a change in follow-up frequency or early intervention as compared with current standard care. As genomic technologies become more common in cancer care, it is hoped that such an assay, once validated, will become part of a new model for the standard management of LGDs in similar health systems.

Discretely Integrated Condition Event (DICE) Simulation for Pharmacoeconomics

Several decision-analytic modeling techniques are in use for pharmacoeconomic analyses. Discretely integrated condition event (DICE) simulation is proposed as a unifying approach that has been deliberately designed to meet the modeling requirements in a straightforward transparent way, without forcing assumptions (e.g., only one transition per cycle) or unnecessary complexity. At the core of DICE are conditions that represent aspects that persist over time. They have levels that can change and many may coexist. Events reflect instantaneous occurrences that may modify some conditions or the timing of other events. The conditions are discretely integrated with events by updating their levels at those times. Profiles of determinant values allow for differences among patients in the predictors of the disease course. Any number of valuations (e.g., utility, cost, willingness-to-pay) of conditions and events can be applied concurrently in a single run. A DICE model is conveniently specified in a series of tables that follow a consistent format and the simulation can be implemented fully in MS Excel, facilitating review and validation. DICE incorporates both state-transition (Markov) models and non-resource-constrained discrete event simulation in a single formulation; it can be executed as a cohort or a microsimulation; and deterministically or stochastically.

The Melanoma MAICare Framework: A Microsimulation Model for the Assessment of Individualized Cancer Care

Recently, new but expensive treatments have become available for metastatic melanoma. These improve survival, but in view of the limited funds available, cost-effectiveness needs to be evaluated. Most cancer cost-effectiveness models are based on the observed clinical events such as recurrence- free and overall survival. Times at which events are recorded depend not only on the effectiveness of treatment but also on the timing of examinations and the types of tests performed. Our objective was to construct a microsimulation model framework that describes the melanoma disease process using a description of underlying tumor growth as well as its interaction with diagnostics, treatments, and surveillance. The framework should allow for exploration of the impact of simultaneously altering curative treatment approaches in different phases of the disease as well as altering diagnostics. The developed framework consists of two components, namely, the disease model and the clinical management module. The disease model consists of a tumor level, describing growth and metastasis of the tumor, and a patient level, describing clinically observed states, such as recurrence and death. The clinical management module consists of the care patients receive. This module interacts with the disease process, influencing the rate of transition between tumor growth states at the tumor level and the rate of detecting a recurrence at the patient level. We describe the framework as the required input and the model output. Furthermore, we illustrate model calibration using registry data and data from the literature.

Development of a cost-effectiveness model for optimisation of the screening interval in diabetic retinopathy screening

BACKGROUND

The English NHS Diabetic Eye Screening Programme was established in 2003. Eligible people are invited annually for digital retinal photography screening. Those found to have potentially sight-threatening diabetic retinopathy (STDR) are referred to surveillance clinics or to Hospital Eye Services.

OBJECTIVES

To determine whether personalised screening intervals are cost-effective.

DESIGN

Risk factors were identified in Gloucestershire, UK using survival modelling. A probabilistic decision hidden (unobserved) Markov model with a misgrading matrix was developed. This informed estimation of lifetime costs and quality-adjusted life-years (QALYs) in patients without STDR. Two personalised risk stratification models were employed: two screening episodes (SEs) (low, medium or high risk) or one SE with clinical information (low, medium-low, medium-high or high risk). The risk factor models were validated in other populations.

SETTING

Gloucestershire, Nottinghamshire, South London and East Anglia (all UK).

PARTICIPANTS

People with diabetes in Gloucestershire with risk stratification model validation using data from Nottinghamshire, South London and East Anglia.

MAIN OUTCOME MEASURES

Personalised risk-based algorithm for screening interval; cost-effectiveness of different screening intervals.

RESULTS

Data were obtained in Gloucestershire from 12,790 people with diabetes with known risk factors to derive the risk estimation models, from 15,877 people to inform the uptake of screening and from 17,043 people to inform the health-care resource-usage costs. Two stratification models were developed: one using only results from previous screening events and one using previous screening and some commonly available GP data. Both models were capable of differentiating groups at low and high risk of development of STDR. The rate of progression to STDR was 5 per 1000 person-years (PYs) in the lowest decile of risk and 75 per 1000 PYs in the highest decile. In the absence of personalised risk stratification, the most cost-effective screening interval was to screen all patients every 3 years, with a 46% probability of this being cost-effective at a £30,000 per QALY threshold. Using either risk stratification models, screening patients at low risk every 5 years was the most cost-effective option, with a probability of 99-100% at a £30,000 per QALY threshold. For the medium-risk groups screening every 3 years had a probability of 43-48% while screening high-risk groups every 2 years was cost-effective with a probability of 55-59%.

CONCLUSIONS

The study found that annual screening of all patients for STDR was not cost-effective. Screening this entire cohort every 3 years was most likely to be cost-effective. When personalised intervals are applied, screening those in our low-risk groups every 5 years was found to be cost-effective. Screening high-risk groups every 2 years further improved the cost-effectiveness of the programme. There was considerable uncertainty in the estimated incremental costs and in the incremental QALYs, particularly with regard to implications of an increasing proportion of maculopathy cases receiving intravitreal injection rather than laser treatment. Future work should focus on improving the understanding of risk, validating in further populations and investigating quality issues in imaging and assessment including the potential for automated image grading.

STUDY REGISTRATION

Integrated Research Application System project number 118959.

FUNDING DETAILS

The National Institute for Health Research Health Technology Assessment programme.

Agent-Based Modeling of Chronic Diseases: A Narrative Review and Future Research Directions

The United States is experiencing an epidemic of chronic disease. As the US population ages, health care providers and policy makers urgently need decision models that provide systematic, credible prediction regarding the prevention and treatment of chronic diseases to improve population health management and medical decision-making. Agent-based modeling is a promising systems science approach that can model complex interactions and processes related to chronic health conditions, such as adaptive behaviors, feedback loops, and contextual effects. This article introduces agent-based modeling by providing a narrative review of agent-based models of chronic disease and identifying the characteristics of various chronic health conditions that must be taken into account to build effective clinical- and policy-relevant models. We also identify barriers to adopting agent-based models to study chronic diseases. Finally, we discuss future research directions of agent-based modeling applied to problems related to specific chronic health conditions.

Improving the planning of the GP workforce in Australia: a simulation model incorporating work transitions, health need and service usage

BACKGROUND

In Australia, the approach to health workforce planning has been supply-led and resource-driven rather than need-based. The result has been cycles of shortages and oversupply. These approaches have tended to use age and sex projections as a measure of need or demand for health care. Less attention has been given to more complex aspects of the population, such as the increasing proportion of the ageing population and increasing levels of chronic diseases or changes in the mix of health care providers or their productivity levels. These are difficult measures to get right and so are often avoided. This study aims to develop a simulation model for planning the general practice workforce in South Australia that incorporates work transitions, health need and service usage.

METHODS

A simulation model was developed with two sub-models--a supply sub-model and a need sub-model. The supply sub-model comprised three components--training, supply and productivity--and the need sub-model described population size, health needs, service utilisation rates and productivity. A state transition cohort model is used to estimate the future supply of GPs, accounting for entries and exits from the workforce and changes in location and work status. In estimating the required number of GPs, the model used incidence and prevalence data, combined with age, gender and condition-specific utilisation rates. The model was run under alternative assumptions reflecting potential changes in need and utilisation rates over time.

RESULTS

The supply sub-model estimated the number of full-time equivalent (FTE) GP stock in SA for the period 2004-2011 and was similar to the observed data, although it had a tendency to overestimate the GP stock. The three scenarios presented for the demand sub-model resulted in different outcomes for the estimated required number of GPs. For scenario one, where utilisation rates in 2003 were assumed optimal, the model predicted fewer FTE GPs were required than was observed. In scenario 2, where utilisation rates in 2013 were assumed optimal, the model matched observed data, and in scenario 3, which assumed increasing age- and gender-specific needs over time, the model predicted more FTE GPs were required than was observed.

CONCLUSIONS

This study provides a robust methodology for determining supply and demand for one professional group at a state level. The supply sub-model was fitted to accurately represent workforce behaviours. In terms of demand, the scenario analysis showed variation in the estimations under different assumptions that demonstrates the value of monitoring population-based need over time. In the meantime, expert opinion might identify the most relevant scenario to be used in projecting workforce requirements.

Cost effectiveness and value of information analyses of islet cell transplantation in the management of 'unstable' type 1 diabetes mellitus

BACKGROUND

Islet cell transplantation is a method to stabilize type 1 diabetes patients with hypoglycemia unawareness and unstable blood glucose levels by reducing insulin dependency and protecting against severe hypoglycemia through restoring endogenous insulin secretion. This study analyses the current cost-effectiveness of this technology and estimates the value of further research to reduce uncertainty around cost-effectiveness.

METHODS

We performed a cost-utility analysis using a Markov cohort model with a mean patient age of 49 to simulate costs and health outcomes over a life-time horizon. Our analysis used intensive insulin therapy (IIT) as comparator and took the provincial healthcare provider perspective. Cost and effectiveness data for up to four transplantations per patient came from the University of Alberta hospital. Costs are expressed in 2012 Canadian dollars and effectiveness in quality-adjusted life-years (QALYs) and life years. To characterize the uncertainty around expected outcomes, we carried out a probabilistic sensitivity analysis within the Bayesian decision-analytic framework. We performed a value-of-information analysis to identify priority areas for future research under various scenarios. We applied a structural sensitivity analysis to assess the dependence of outcomes on model characteristics.

RESULTS

Compared to IIT, islet cell transplantation using non-generic (generic) immunosuppression had additional costs of $150,006 ($112,023) per additional QALY, an average gain of 3.3 life years, and a probability of being cost-effective of 0.5 % (28.3 %) at a willingness-to-pay threshold of $100,000 per QALY. At this threshold the non-generic technology has an expected value of perfect information (EVPI) of $260,744 for Alberta. This increases substantially in cost-reduction scenarios. The research areas with the highest partial EVPI are costs, followed by natural history, and effectiveness and safety.

CONCLUSIONS

Current transplantation technology provides substantial improvements in health outcomes over conventional therapy for highly selected patients with 'unstable' type 1 diabetes. However, it is much more costly and so is not cost-effective. The value of further research into the cost-effectiveness is dependent upon treatment costs. Further, we suggest the value of information should not only be derived from current data alone when knowing that this data will most likely change in the future.

Methods for Health Economic Evaluation of Vaccines and Immunization Decision Frameworks: A Consensus Framework from a European Vaccine Economics Community

BACKGROUND

Incremental cost-effectiveness and cost-utility analyses [health economic evaluations (HEEs)] of vaccines are routinely considered in decision making on immunization in various industrialized countries. While guidelines advocating more standardization of such HEEs (mainly for curative drugs) exist, several immunization-specific aspects (e.g. indirect effects or discounting approach) are still a subject of debate within the scientific community.

OBJECTIVE

The objective of this study was to develop a consensus framework for HEEs of vaccines to support the development of national guidelines in Europe.

METHODS

A systematic literature review was conducted to identify prevailing issues related to HEEs of vaccines. Furthermore, European experts in the field of health economics and immunization decision making were nominated and asked to select relevant aspects for discussion. Based on this, a workshop was held with these experts. Aspects on 'mathematical modelling', 'health economics' and 'decision making' were debated in group-work sessions (GWS) to formulate recommendations and/or--if applicable--to state 'pros' and 'contras'.

RESULTS

A total of 13 different aspects were identified for modelling and HEE: model selection, time horizon of models, natural disease history, measures of vaccine-induced protection, duration of vaccine-induced protection, indirect effects apart from herd protection, target population, model calibration and validation, handling uncertainty, discounting, health-related quality of life, cost components, and perspectives. For decision making, there were four aspects regarding the purpose and the integration of HEEs of vaccines in decision making as well as the variation of parameters within uncertainty analyses and the reporting of results from HEEs. For each aspect, background information and an expert consensus were formulated.

CONCLUSIONS

There was consensus that when HEEs are used to prioritize healthcare funding, this should be done in a consistent way across all interventions, including vaccines. However, proper evaluation of vaccines implies using tools that are not commonly used for therapeutic drugs. Due to the complexity of and uncertainties around vaccination, transparency in the documentation of HEEs and during subsequent decision making is essential.

The potential health and economic effect of a Body Mass Index decrease in the overweight and obese population in Belgium

OBJECTIVES

The aim of the study was to examine the health and economic consequences of a Body Mass Index decrease in the Belgian overweight and obese population over a 20-year time period.

STUDY DESIGN

Health economic evaluation study.

METHODS

A Markov decision-analytic model using a societal perspective was applied, projecting the one-year results of a one unit Body Mass Index decrease over a time horizon of 20 years. Scenario analysis was applied evaluating the effects on the results of an alternative modelling assumption. One-way sensitivity analysis and probabilistic sensitivity analysis were performed to assess the effects on the findings of varying key input parameters.

RESULTS

A one unit Body Mass Index decrease resulted in improved health outcomes and cost savings/patient (overweight women: 785€, obese women: 1039€, overweight men: 613€, obese men: 864€). For the total overweight and obese population, a cost saving of 2.8 billion euros was estimated. Considering the economic value of the health impact would result in a total economic benefit of about 15.9 billion euros for the Belgian society over a 20 year time period.

CONCLUSIONS

A one unit Body Mass Index reduction in the overweight and obese population in Belgium was found to be associated with improved health outcomes and cost savings. The evidence of such research can assist regulatory bodies in the allocation of healthcare budgets in a more efficient way.

A method for using real world data in breast cancer modeling

OBJECTIVES

Today, hospitals and other health care-related institutions are accumulating a growing bulk of real world clinical data. Such data offer new possibilities for the generation of disease models for the health economic evaluation. In this article, we propose a new approach to leverage cancer registry data for the development of Markov models. Records of breast cancer patients from a clinical cancer registry were used to construct a real world data driven disease model.

METHODS

We describe a model generation process which maps database structures to disease state definitions based on medical expert knowledge. Software was programmed in Java to automatically derive a model structure and transition probabilities. We illustrate our method with the reconstruction of a published breast cancer reference model derived primarily from clinical study data. In doing so, we exported longitudinal patient data from a clinical cancer registry covering eight years. The patient cohort (n=892) comprised HER2-positive and HER2-negative women treated with or without Trastuzumab.

RESULTS

The models generated with this method for the respective patient cohorts were comparable to the reference model in their structure and treatment effects. However, our computed disease models reflect a more detailed picture of the transition probabilities, especially for disease free survival and recurrence.

CONCLUSIONS

Our work presents an approach to extract Markov models semi-automatically using real world data from a clinical cancer registry. Health care decision makers may benefit from more realistic disease models to improve health care-related planning and actions based on their own data.

Management of localized and advanced prostate cancer in Canada: A lifetime cost and quality-adjusted life-year analysis

BACKGROUND

To the authors' knowledge, the literature to date lacks studies examining lifetime costs and quality-adjusted life-years (QALYs) of prostate cancer (PCa) management strategies that integrate localized and advanced disease. The objective of the current study was to assess lifetime costs and QALYs associated with contemporary PCa management strategies across risk groups by integrating localized and advanced disease.

METHODS

The authors' validated Markov chain Monte Carlo model was used to predict lifetime direct costs and QALYs. The health states modeled were active surveillance, initial treatments (radical prostatectomy or radiotherapy), PCa recurrence, PCa recurrence free, metastatic castration-resistant prostate cancer, and death (cause specific/other causes). Data regarding treatment distribution, state transition probabilities, adverse effects of management options, costs, utilities, and disutilities were derived from the published literature.

RESULTS

The total cost per patient for the overall cohort increased from $18,503 at 5 years to $28,032 and $39,143, respectively, at 10 years and 15 years. Furthermore, the results indicated the influence of risk group on total cost, with the high-risk group accruing the maximum per patient cost followed by the intermediate-risk and low-risk groups. Active surveillance was found to confer the most QALYs (12.5 years) and was the least costly strategy ($18,452) for individuals at low risk. For all risk groups, radical prostatectomy was less costly and conferred modestly more QALYs compared with intensity-modulated radiotherapy modalities.

CONCLUSIONS

Public health care systems in Canada and elsewhere are operating under budget constraints to allocate finite resources. The findings of the current study might inform discussions concerning budget planning to provide health care services.

Cost-Effectiveness of a Statewide Campaign to Promote Aspirin Use for Primary Prevention of Cardiovascular Disease

BACKGROUND

The U.S. Preventive Services Task Force in 2009 recommended increased aspirin use for primary prevention of cardiovascular disease (CVD) in men ages 45 to 79 years and women ages 55 to 79 years for whom benefit outweighs risk. This study estimated the clinical efficacy and cost-effectiveness of a statewide public and health professional awareness campaign to increase regular aspirin use among the target population in Minnesota to reduce first CVD events.

METHODS AND RESULTS

A state-transition Markov model was developed, adopting a payer perspective and lifetime time horizon. The main outcomes of interest were quality-adjusted life years, costs, and the number of CVD events averted among those without a prior CVD history. The model was based on real-world data about campaign effectiveness from representative state-specific aspirin use and event rates, and estimates from the scholarly literature. Implementation of a campaign was predicted to avert 9874 primary myocardial infarctions in men and 1223 primary ischemic strokes in women in the target population. Increased aspirin use was associated with as many as 7222 more major gastrointestinal bleeding episodes. The cost-effectiveness analysis indicated cost-saving results for both the male and female target populations.

CONCLUSIONS

Using current U.S. Preventive Services Task Force recommendations, a state public and health professional awareness campaign would likely provide clinical benefit and be economically attractive. With clinician adjudication of individual benefit and risk, mechanisms can be made available that would facilitate achievement of aspirin's beneficial impact on lowering risk of primary CVD events, with minimization of adverse outcomes.

Cost-effectiveness of minimally invasive sacroiliac joint fusion

BACKGROUND

Sacroiliac joint (SIJ) disorders are common in patients with chronic lower back pain. Minimally invasive surgical options have been shown to be effective for the treatment of chronic SIJ dysfunction.

OBJECTIVE

To determine the cost-effectiveness of minimally invasive SIJ fusion.

METHODS

Data from two prospective, multicenter, clinical trials were used to inform a Markov process cost-utility model to evaluate cumulative 5-year health quality and costs after minimally invasive SIJ fusion using triangular titanium implants or non-surgical treatment. The analysis was performed from a third-party perspective. The model specifically incorporated variation in resource utilization observed in the randomized trial. Multiple one-way and probabilistic sensitivity analyses were performed.

RESULTS

SIJ fusion was associated with a gain of approximately 0.74 quality-adjusted life years (QALYs) at a cost of US$13,313 per QALY gained. In multiple one-way sensitivity analyses all scenarios resulted in an incremental cost-effectiveness ratio (ICER) <$26,000/QALY. Probabilistic analyses showed a high degree of certainty that the maximum ICER for SIJ fusion was less than commonly selected thresholds for acceptability (mean ICER =$13,687, 95% confidence interval $5,162-$28,085). SIJ fusion provided potential cost savings per QALY gained compared to non-surgical treatment after a treatment horizon of greater than 13 years.

CONCLUSION

Compared to traditional non-surgical treatments, SIJ fusion is a cost-effective, and, in the long term, cost-saving strategy for the treatment of SIJ dysfunction due to degenerative sacroiliitis or SIJ disruption.

Dealing with Time in Health Economic Evaluation: Methodological Issues and Recommendations for Practice

Time is an important aspect of health economic evaluation, as the timing and duration of clinical events, healthcare interventions and their consequences all affect estimated costs and effects. These issues should be reflected in the design of health economic models. This article considers three important aspects of time in modelling: (1) which cohorts to simulate and how far into the future to extend the analysis; (2) the simulation of time, including the difference between discrete-time and continuous-time models, cycle lengths, and converting rates and probabilities; and (3) discounting future costs and effects to their present values. We provide a methodological overview of these issues and make recommendations to help inform both the conduct of cost-effectiveness analyses and the interpretation of their results. For choosing which cohorts to simulate and how many, we suggest analysts carefully assess potential reasons for variation in cost effectiveness between cohorts and the feasibility of subgroup-specific recommendations. For the simulation of time, we recommend using short cycles or continuous-time models to avoid biases and the need for half-cycle corrections, and provide advice on the correct conversion of transition probabilities in state transition models. Finally, for discounting, analysts should not only follow current guidance and report how discounting was conducted, especially in the case of differential discounting, but also seek to develop an understanding of its rationale. Our overall recommendations are that analysts explicitly state and justify their modelling choices regarding time and consider how alternative choices may impact on results.

Estimation of the cost-effectiveness of apixaban versus vitamin K antagonists in the management of atrial fibrillation in Argentina

Apixaban, a novel oral anticoagulant which has been approved for the prevention of stroke and systemic embolism in non-valvular atrial fibrillation, reduces both ischemic and haemorrhagic stroke and produces fewer bleedings than vitamin K antagonist warfarin. These clinical results lead to a decrease in health care resource utilization and, therefore, have a positive impact on health economics of atrial fibrillation. The cost-effectiveness of apixaban has been assessed in a variety of clinical settings and countries. However, data from emergent markets, as is the case of Argentina, are still scarce.We performed a cost-effectiveness analysis of apixaban versus warfarin in non-valvular atrial fibrillation (NVAF) in patients suitable for oral anticoagulation in Argentina. A Markov-based model including both costs and effects were used to simulate a cohort of patients with NVAF. Local epidemiological, resource utilization and cost data were used and all inputs were validated by a Delphi Panel of local experts. We adopted the payer's perspective with costs expressed in 2012 US Dollars.The study revealed that apixaban is cost-effective compared with warfarin using a willingness to pay threshold ranging from 1 to 3 per capita Gross Domestic Product (11558 - 34664 USD) with an incremental cost-effectiveness ratio of 786.08 USD per QALY gained. The benefit is primarily a result of the reduction in stroke and bleeding events.The study demonstrates that apixaban is a cost-effective alternative to warfarin in Argentina.

How to model temporal changes in comorbidity for cancer patients using prospective cohort data

BACKGROUND

The presence of comorbid conditions is strongly related to survival and also affects treatment choices in cancer patients. This comorbidity is often quantified by the Charlson Comorbidity Index (CCI) using specific weights (1, 2, 3, or 6) for different comorbidities. It has been shown that the CCI increases at different times and with different sizes, so that traditional time to event analysis is not adequate to assess these temporal changes. Here, we present a method to model temporal changes in CCI in cancer patients using data from PCBaSe Sweden, a nation-wide population-based prospective cohort of men diagnosed with prostate cancer. Our proposed model is based on the assumption that a change in comorbidity, as quantified by the CCI, is an irreversible one-way process, i.e., CCI accumulates over time and cannot decrease.

METHODS

CCI was calculated based on 17 disease categories, which were defined using ICD-codes for discharge diagnoses in the National Patient Register. A state transition model in discrete time steps (i.e., four weeks) was applied to capture all changes in CCI. The transition probabilities were estimated from three modelling steps: 1) Logistic regression model for vital status, 2) Logistic regression model to define any changes in CCI, and 3) Poisson regression model to determine the size of CCI change, with an additional logistic regression model for CCI changes ≥ 6. The four models combined yielded parameter estimates to calculate changes in CCI with their confidence intervals.

RESULTS

These methods were applied to men with low-risk prostate cancer who received active surveillance (AS), radical prostatectomy (RP), or curative radiotherapy (RT) as primary treatment. There were large differences in CCI changes according to treatment.

CONCLUSIONS

Our method to model temporal changes in CCI efficiently captures changes in comorbidity over time with a small number of regression analyses to perform - which would be impossible with tradition time to event analyses. However, our approach involves a simulation step that is not yet included in standard statistical software packages. In our prostate cancer example we showed that there are large differences in development of comorbidities among men receiving different treatments for prostate cancer.

Climate influences on the cost-effectiveness of vector-based interventions against malaria in elimination scenarios

Despite the dependence of mosquito population dynamics on environmental conditions, the associated impact of climate and climate change on present and future malaria remains an area of ongoing debate and uncertainty. Here, we develop a novel integration of mosquito, transmission and economic modelling to assess whether the cost-effectiveness of indoor residual spraying (IRS) and long-lasting insecticidal nets (LLINs) against Plasmodium falciparum transmission by Anopheles gambiae s.s. mosquitoes depends on climatic conditions in low endemicity scenarios. We find that although temperature and rainfall affect the cost-effectiveness of IRS and/or LLIN scale-up, whether this is sufficient to influence policy depends on local endemicity, existing interventions, host immune response to infection and the emergence rate of insecticide resistance. For the scenarios considered, IRS is found to be more cost-effective than LLINs for the same level of scale-up, and both are more cost-effective at lower mean precipitation and higher variability in precipitation and temperature. We also find that the dependence of peak transmission on mean temperature translates into optimal temperatures for vector-based intervention cost-effectiveness. Further cost-effectiveness analysis that accounts for country-specific epidemiological and environmental heterogeneities is required to assess optimal intervention scale-up for elimination and better understand future transmission trends under climate change.

Development of a web-based tool for the assessment of health and economic outcomes of the European Innovation Partnership on Active and Healthy Ageing (EIP on AHA)

BACKGROUND

The European Innovation Partnership on Active and Healthy Ageing (EIP on AHA) is a European Commission led policy initiative to address the challenges of demographic change in Europe. For monitoring the health and economic impact of the social and technological innovations carried out by more than 500 stakeholder's groups ('commitments') participating in the EIP on AHA, a generic and flexible web-based monitoring and assessment tool is currently being developed.

AIM

This paper describes the approach for developing and implementing this web-based tool, its main characteristics and capability to provide specific outcomes that are of value to the developers of an intervention, as well as a series of case studies planned before wider rollout.

METHODS

The tool builds up from a variety of surrogate endpoints commonly used across the diverse set of EIP on AHA commitments in order to estimate health and economic outcomes in terms of incremental changes in quality adjusted life years (QALYs) as well as health and social care utilisation. A highly adaptable Markov model with initially three mutually exclusive health states ('baseline health', 'deteriorated health' and 'death') provides the basis for the tool which draws from an extensive database of epidemiological, economic and effectiveness data; and also allows further customisation through remote data entry enabling more accurate and context specific estimation of intervention impact. Both probabilistic sensitivity analysis and deterministic scenario analysis allow assessing the impact of parameter uncertainty on intervention outcomes. A set of case studies, ranging from the pre-market assessment of early healthcare technologies to the retrospective analysis of established care pathways, will be carried out before public rollout, which is envisaged end 2015.

CONCLUSION

Monitoring the activities carried out within the EIP on AHA requires an approach that is both flexible and consistent in the way health and economic impact is estimated across interventions and commitments. The added value for users of the MAFEIP-tool is its ability to provide an early assessment of the likelihood that interventions in their current design will achieve the anticipated impact, and also to identify what drives interventions' effectiveness or efficiency to guide further design, development or evaluation.

The use of fenestrated and branched endovascular aneurysm repair for juxtarenal and thoracoabdominal aneurysms: a systematic review and cost-effectiveness analysis

BACKGROUND

Patients with large abdominal aortic aneurysms (AAAs) are usually offered reparative treatment given the high mortality risk. There is uncertainty about how to treat juxtarenal AAAs (JRAAAs) or thoracoabdominal aortic aneurysms (TAAAs). Endovascular repair of an abdominal aortic aneurysm (EVAR) is often seen as safer and easier than open surgical repair (OSR). However, endovascular treatment of JRAAAs or TAAAs requires specially manufactured stent grafts, with openings to allow blood to reach branches of the aorta. Commissioners are receiving increasing requests for fenestrated EVAR (fEVAR) and branched EVAR (bEVAR), but it is unclear whether or not the extra cost of fEVAR or bEVAR is justified by advantages for patients.

OBJECTIVE(S)

To assess the clinical effectiveness, safety and cost-effectiveness of fEVAR and bEVAR in comparison with conventional treatment (i.e. no surgery) or OSR for two populations: JRAAAs and TAAAs.

DATA SOURCES

Resources were searched from inception to October 2013, including MEDLINE (OvidSP), EMBASE (OvidSP) and the Cochrane Central Register of Controlled Trials (Wiley) and, additionally, for cost-effectiveness, NHS Economic Evaluation Database (NHS EED; Wiley) and EconLit (EBSCOhost). Conference abstracts were also searched.

REVIEW METHODS

Studies were included based on an intervention of either fEVAR or bEVAR and a comparator of either OSR or no surgery. For clinical effectiveness, observational studies were excluded only if they were not comparative, i.e. explicitly selected on the basis of prognosis.

RESULTS

For clinical effectiveness, searches retrieved 5253 records before deduplication. Owing to overlap between the databases, 1985 duplicate records were removed. Of the remaining 3268 records, based on titles and abstracts, 3244 records were excluded, leaving 24 publications to be ordered. All 24 studies were excluded as none of them satisfied the inclusion criteria. Sixteen studies were excluded on study design, six on intervention and two on comparator. Five out of 16 studies excluded on study design reported a comparison. However, all of the studies acknowledged that they had groups that were not comparable at baseline given that they had selectively assigned younger, fitter patients to OSR. Therefore, these studies were considered 'non-comparative'. For cost-effectiveness, searches identified 104 references before deduplication. Owing to overlap between the databases, 34 duplicate records were removed. Of the remaining 70 records, seven were included for the full assessment based on initial screening. After a full-text review, no studies were included. Because of the lack of clinical effectiveness evidence and difficulty in estimating costs given the rapidly changing and variable technology, a cost-effectiveness analysis (CEA) was not performed. Instead a detailed description of modelling methods was provided.

CONCLUSIONS

Despite a thorough search, no studies could be found that met the inclusion criteria. All studies that compared either fEVAR or bEVAR with either OSR or no surgery explicitly selected patients based on prognosis, i.e. essentially the populations for each comparator were not the same. Despite not being able to conduct a CEA, we have provided detailed methods for the conduct if data becomes available.

FUTURE WORK

We recommend at least one clinical trial to provide an unbiased estimate of effect for fEVAR/bEVAR compared with OSR or no surgery. This trial should also collect data for a CEA.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42013006051.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Optical coherence tomography for the diagnosis, monitoring and guiding of treatment for neovascular age-related macular degeneration: a systematic review and economic evaluation

BACKGROUND

Age-related macular degeneration is the most common cause of sight impairment in the UK. In neovascular age-related macular degeneration (nAMD), vision worsens rapidly (over weeks) due to abnormal blood vessels developing that leak fluid and blood at the macula.

OBJECTIVES

To determine the optimal role of optical coherence tomography (OCT) in diagnosing people newly presenting with suspected nAMD and monitoring those previously diagnosed with the disease.

DATA SOURCES

Databases searched: MEDLINE (1946 to March 2013), MEDLINE In-Process & Other Non-Indexed Citations (March 2013), EMBASE (1988 to March 2013), Biosciences Information Service (1995 to March 2013), Science Citation Index (1995 to March 2013), The Cochrane Library (Issue 2 2013), Database of Abstracts of Reviews of Effects (inception to March 2013), Medion (inception to March 2013), Health Technology Assessment database (inception to March 2013).

REVIEW METHODS

Types of studies: direct/indirect studies reporting diagnostic outcomes.

INDEX TEST

time domain optical coherence tomography (TD-OCT) or spectral domain optical coherence tomography (SD-OCT).

COMPARATORS

clinical evaluation, visual acuity, Amsler grid, colour fundus photographs, infrared reflectance, red-free images/blue reflectance, fundus autofluorescence imaging, indocyanine green angiography, preferential hyperacuity perimetry, microperimetry. Reference standard: fundus fluorescein angiography (FFA). Risk of bias was assessed using quality assessment of diagnostic accuracy studies, version 2. Meta-analysis models were fitted using hierarchical summary receiver operating characteristic curves. A Markov model was developed (65-year-old cohort, nAMD prevalence 70%), with nine strategies for diagnosis and/or monitoring, and cost-utility analysis conducted. NHS and Personal Social Services perspective was adopted. Costs (2011/12 prices) and quality-adjusted life-years (QALYs) were discounted (3.5%). Deterministic and probabilistic sensitivity analyses were performed.

RESULTS

In pooled estimates of diagnostic studies (all TD-OCT), sensitivity and specificity [95% confidence interval (CI)] was 88% (46% to 98%) and 78% (64% to 88%) respectively. For monitoring, the pooled sensitivity and specificity (95% CI) was 85% (72% to 93%) and 48% (30% to 67%) respectively. The FFA for diagnosis and nurse-technician-led monitoring strategy had the lowest cost (£ 39,769; QALYs 10.473) and dominated all others except FFA for diagnosis and ophthalmologist-led monitoring (£ 44,649; QALYs 10.575; incremental cost-effectiveness ratio £ 47,768). The least costly strategy had a 46.4% probability of being cost-effective at £ 30,000 willingness-to-pay threshold.

LIMITATIONS

Very few studies provided sufficient information for inclusion in meta-analyses. Only a few studies reported other tests; for some tests no studies were identified. The modelling was hampered by a lack of data on the diagnostic accuracy of strategies involving several tests.

CONCLUSIONS

Based on a small body of evidence of variable quality, OCT had high sensitivity and moderate specificity for diagnosis, and relatively high sensitivity but low specificity for monitoring. Strategies involving OCT alone for diagnosis and/or monitoring were unlikely to be cost-effective. Further research is required on (i) the performance of SD-OCT compared with FFA, especially for monitoring but also for diagnosis; (ii) the performance of strategies involving combinations/sequences of tests, for diagnosis and monitoring; (iii) the likelihood of active and inactive nAMD becoming inactive or active respectively; and (iv) assessment of treatment-associated utility weights (e.g. decrements), through a preference-based study.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42012001930.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Continuous-Time Semi-Markov Models in Health Economic Decision Making

Continuous-time state transition models may end up having large unwieldy structures when trying to represent all relevant stages of clinical disease processes by means of a standard Markov model. In such situations, a more parsimonious, and therefore easier-to-grasp, model of a patient’s disease progression can often be obtained by assuming that the future state transitions do not depend only on the present state (Markov assumption) but also on the past through time since entry in the present state. Despite that these so-called semi-Markov models are still relatively straightforward to specify and implement, they are not yet routinely applied in health economic evaluation to assess the cost-effectiveness of alternative interventions. To facilitate a better understanding of this type of model among applied health economic analysts, the first part of this article provides a detailed discussion of what the semi-Markov model entails and how such models can be specified in an intuitive way by adopting an approach called vertical modeling. In the second part of the article, we use this approach to construct a semi-Markov model for assessing the long-term cost-effectiveness of 3 disease management programs for heart failure. Compared with a standard Markov model with the same disease states, our proposed semi-Markov model fitted the observed data much better. When subsequently extrapolating beyond the clinical trial period, these relatively large differences in goodness-of-fit translated into almost a doubling in mean total cost and a 60-d decrease in mean survival time when using the Markov model instead of the semi-Markov model. For the disease process considered in our case study, the semi-Markov model thus provided a sensible balance between model parsimoniousness and computational complexity.

Cost-Effectiveness of New Direct-Acting Antivirals to Prevent Post-Liver Transplant Recurrent Hepatitis

Preliminary studies on HCV-cirrhotics listed for transplant suggest that sofosbuvir in combination with ribavirin is very effective in promoting viral clearance and preventing disease recurrence. Unfortunately, the high cost of such treatment (€46 500 per 12 weeks of treatment) makes its cost-effectiveness questionable. A semi-Markov model was developed to assess the cost-effectiveness of sofosbuvir/ribavirin treatment in cirrhotic patients without HCC (HCV-CIRRH) and with HCC (HCV-HCC) listed for transplant. In the base-case analysis, the incremental cost-effectiveness ratio for 24 weeks of sofosbuvir/ribavirin was €44 875 per quality-adjusted life-year gained in HCV-CIRRH and €60 380 in HCV-HCC patients. Both results were above the willingness to pay threshold of €37 000 per quality-adjusted life-year. Our data also show that in order to remain cost-effective (with a 24-week treatment), any novel interferon-free treatment endowed with ideal efficacy should cost less than €67 224 or €95 712 in HCV-cirrhotics with and without HCC, respectively. The results shows that sofosbuvir/ribavirin therapy, given to patients listed for transplant, is not cost-effective at current prices despite being very effective, and new, more effective treatments will have little economic margins to remain cost-effective. New interferon-free combinations have the potential to revolutionize the treatment and prognosis of HCV-positive patients listed for transplant; however, without sustainable prices, this revolution is unlikely to happen.

Systematic narrative review of decision frameworks to select the appropriate modelling approaches for health economic evaluations

Background

In constructing or appraising a health economic model, an early consideration is whether the modelling approach selected is appropriate for the given decision problem. Frameworks and taxonomies that distinguish between modelling approaches can help make this decision more systematic and this study aims to identify and compare the decision frameworks proposed to date on this topic area.

Methods

A systematic review was conducted to identify frameworks from peer-reviewed and grey literature sources. The following databases were searched: OVID Medline and EMBASE; Wiley’s Cochrane Library and Health Economic Evaluation Database; PubMed; and ProQuest.

Results

Eight decision frameworks were identified, each focused on a different set of modelling approaches and employing a different collection of selection criterion. The selection criteria can be categorized as either: (i) structural features (i.e. technical elements that are factual in nature) or (ii) practical considerations (i.e. context-dependent attributes). The most commonly mentioned structural features were population resolution (i.e. aggregate vs. individual) and interactivity (i.e. static vs. dynamic). Furthermore, understanding the needs of the end-users and stakeholders was frequently incorporated as a criterion within these frameworks.

Conclusions

There is presently no universally-accepted framework for selecting an economic modelling approach. Rather, each highlights different criteria that may be of importance when determining whether a modelling approach is appropriate. Further discussion is thus necessary as the modelling approach selected will impact the validity of the underlying economic model and have downstream implications on its efficiency, transparency and relevance to decision-makers.

Electronic supplementary material

The online version of this article (doi:10.1186/s13104-015-1202-0) contains supplementary material, which is available to authorized users.

Simulation modeling of the impact of proposed new simultaneous liver and kidney transplantation policies

BACKGROUND

Increasing use of kidney grafts for simultaneous liver and kidney (SLK) transplants is causing concern about the most effective utilization of scarce kidney graft resources. This study evaluated the impact of implementing the proposed United Network for Organ Sharing SLK transplant policy on outcomes for end-stage liver disease (ESLD) and end-stage renal disease (ESRD) patients awaiting transplant.

METHODS

A Markov model was constructed to simulate a hypothetical cohort of ESLD patients over a 30-year time horizon starting from age 50. The model applies the different criteria being considered in the United Network for Organ Sharing policy and tallies outcomes, including numbers of procedures and life years after liver transplant alone (LTA) or SLK transplant.

RESULTS

When 1-week pretransplant dialysis duration is required, the numbers of SLK transplants and LTAs would be 648 and 9,065, respectively. If the pretransplant dialysis duration is extended to 12 weeks, there would be 240 SLK transplants and 9,426 LTAs. This change results in a decrease of 6,483 life years among SLK transplant recipients and an increase of 4,971 life years among LTA recipients. However, by increasing the dialysis duration to 12 weeks from 1 week, 408 kidney grafts would be released to the kidney waitlist because of the decline in SLK transplants; this yields 796 additional life years gained among ESRD patients.

CONCLUSION

Implementation of the proposed SLK transplant policy could restore access to kidney transplants for patients with ESRD albeit at the detriment of patients with ESLD and renal impairment.

A Systematic Review of Research Guidelines in Decision-Analytic Modeling

BACKGROUND

Decision-analytic modeling (DAM) has been increasingly used to aid decision making in health care. The growing use of modeling in economic evaluations has led to increased scrutiny of the methods used.

OBJECTIVE

The objective of this study was to perform a systematic review to identify and critically assess good practice guidelines, with particular emphasis on contemporary developments.

METHODS

A systematic review of English language articles was undertaken to identify articles presenting guidance for good practice in DAM in the evaluation of health care. The inclusion criteria were articles providing guidance or criteria against which to assess good practice in DAM and studies providing criteria or elements for good practice in some areas of DAM. The review covered the period January 1990 to March 2014 and included the following electronic bibliographic databases: Cochrane Library, Cochrane Methodology Register and Health Technology Assessment, NHS Economic Evaluation Database, MEDLINE, and PubMed (Embase). Additional studies were identified by searching references.

RESULTS

Thirty-three articles were included in this review. A practical five-dimension framework was developed that describe the key elements of good research practice that should be considered and reported to increase the credibility of results obtained from DAM in the evaluation of health care.

CONCLUSIONS

This study is the first to critically review all available guidelines and statements of good practice in DAM since 2006. The development of good practice guidelines is an ongoing process, and important efforts have been made to identify what is good practice and to keep these guidelines up to date.

Cost-utility analysis of percutaneous mitral valve repair in inoperable patients with functional mitral regurgitation in German settings

BACKGROUND

To determine the cost-effectiveness of the percutaneous mitral valve repair (PMVR) using Carillon® Mitral Contour System® (Cardiac Dimensions Inc., Kirkland, WA, USA) in patients with congestive heart failure accompanied by moderate to severe functional mitral regurgitation (FMR) compared to the prolongation of optimal medical treatment (OMT).

METHODS

Cost-utility analysis using a combination of a decision tree and Markov process was performed. The clinical effectiveness was determined based on the results of the Transcatheter Implantation of Carillon Mitral Annuloplasty Device (TITAN) trial. The mean age of the target population was 62 years, 77% of the patients were males, 64% of the patients had severe FMR and all patients had New York Heart Association functional class III. The epidemiological, cost and utility data were derived from the literature. The analysis was performed from the German statutory health insurance perspective over 10-year time horizon.

RESULTS

Over 10 years, the total cost was €36,785 in the PMVR arm and €18,944 in the OMT arm. However, PMVR provided additional benefits to patients with an 1.15 incremental quality-adjusted life years (QALY) and an 1.41 incremental life years. The percutaneous procedure was cost-effective in comparison to OMT with an incremental cost-effectiveness ratio of €15,533/QALY. Results were robust in the deterministic sensitivity analysis. In the probabilistic sensitivity analysis with a willingness-to-pay threshold of €35,000/QALY, PMVR had a 84 % probability of being cost-effective.

CONCLUSIONS

Percutaneous mitral valve repair may be cost-effective in inoperable patients with FMR due to heart failure.

Cost-effectiveness of quantitative pretest probability intended to reduce unnecessary medical radiation exposure in emergency department patients with chest pain and dyspnea

OBJECTIVES

Quantitative pretest probability (qPTP) incorporated into a decision support tool with advice can reduce unnecessary diagnostic testing among patients with symptoms suggestive of acute coronary syndrome (ACS) and pulmonary embolism (PE), reducing 30-day costs without an increase in 90-day adverse outcomes. This study estimates long-term (beyond 90-day) costs and outcomes associated with qPTP. The authors hypothesized that qPTP reduces lifetime costs and improves outcomes in low-risk patients with symptoms suggestive of ACS and PE.

METHODS

This was a cost-effectiveness analysis of a multicenter, randomized controlled trial of adult emergency patients with dyspnea and chest pain, in which a clinician encountering a low-risk patient with symptoms suggestive of ACS or PE conducted either the intervention (qPTP for ACS and PE with advice) or the sham (no qPTP and no advice). Effect of the intervention over a patient's lifetime was assessed using a Markov microsimulation model. Short-term costs and outcomes were from the trial; long-term outcomes and costs were from the literature. Outcomes included lifetime transition to PE, ACS, and intracranial hemorrhage (ICH); mortality from cancer, ICH, PE, ACS, renal failure, and ischemic stroke; quality-adjusted life-years (QALYs); and total medical costs compared between simulated intervention and sham groups.

RESULTS

Markov microsimulation for a 40-year-old patient receiving qPTP found lifetime cost savings of $497 for women and $528 for men, associated with small gains in QALYs (2 and 6 days, respectively) and lower rates of cancer mortality in both sexes, but a reduction in ICH only in males. Sensitivity analysis for patients aged 60 years predicted that qPTP would continue to save costs and also reduce mortality from both ICH and cancer. Use of qPTP significantly reduced the lifetime probability of PE diagnosis, with lower probability of death from PE in both sexes aged 40 to 60 years. However, use of qPTP reduced the rate of ACS diagnosis and death from ACS at age 40, but increased the death rate from ACS at age 60 for both sexes.

CONCLUSIONS

Widespread use of a combined qPTP for both ACS and PE has the potential to decrease costs by reducing diagnostic testing, while improving most long-term outcomes in emergency patients with chest pain and dyspnea.

Mathematical modelling in tobacco control research: protocol for a systematic review

INTRODUCTION

Tobacco control researchers have recently become more interested in systems science methods and mathematical modelling techniques as a means to understand how complex inter-relationships among various factors translate into population-level summaries of tobacco use prevalence and its associated medical and social costs. However, there is currently no resource that provides an overview of how mathematical modelling has been used in tobacco control research. This review will provide a summary of studies that employ modelling techniques to predict tobacco-related outcomes. It will also propose a conceptual framework for grouping existing modelling studies by their objectives.

METHODS AND ANALYSIS

We will conduct a systematic review that is informed by Cochrane procedures, as well as guidelines developed for reviews that are specifically intended to inform policy and programme decision-making. We will search 5 electronic databases to identify studies that use a mathematical model to project a tobacco-related outcome. An online data extraction form will be developed based on the ISPOR-SMDM Modeling Good Research Practices. We will perform a qualitative synthesis of included studies.

ETHICS AND DISSEMINATION

Ethical approval is not required for this study. An initial paper, published in a peer-reviewed journal, will provide an overview of our findings. Subsequent papers will provide greater detail on results within each study objective category and an assessment of the risk of bias of these grouped studies.

Cost-effectiveness of adding bedaquiline to drug regimens for the treatment of multidrug-resistant tuberculosis in the UK

OBJECTIVE

To evaluate the cost-effectiveness of adding bedaquiline to a background regimen (BR) of drugs for multidrug-resistant tuberculosis (MDR-TB) in the United Kingdom (UK).

METHODS

A cohort-based Markov model was developed to estimate the incremental cost-effectiveness ratio of bedaquiline plus BR (BBR) versus BR alone (BR) in the treatment of MDR-TB, over a 10-year time horizon. A National Health Service (NHS) and personal social services perspective was considered. Cost-effectiveness was evaluated in terms of Quality-Adjusted Life Years (QALYs) and Disability-Adjusted Life Years (DALYs). Data were sourced from a phase II, placebo-controlled trial, NHS reference costs, and the literature; the US list price of bedaquiline was used and converted to pounds (£18,800). Costs and effectiveness were discounted at a rate of 3.5% per annum. Probabilistic and deterministic sensitivity analysis was conducted.

RESULTS

The total discounted cost per patient (pp) on BBR was £106,487, compared with £117,922 for BR. The total discounted QALYs pp were 5.16 for BBR and 4.01 for BR. The addition of bedaquiline to a BR resulted in a cost-saving of £11,434 and an additional 1.14 QALYs pp over a 10-year period, and is therefore considered to be the dominant (less costly and more effective) strategy over BR. BBR remained dominant in the majority of sensitivity analyses, with a 81% probability of being dominant versus BR in the probabilistic analysis.

CONCLUSIONS

In the UK, bedaquiline is likely to be cost-effective and cost-saving, compared with the current MDR-TB standard of care under a range of scenarios. Cost-savings over a 10-year period were realized from reductions in length of hospitalization, which offset the bedaquiline drug costs. The cost-benefit conclusions held after several sensitivity analyses, thus validating assumptions made, and suggesting that the results would hold even if the actual price of bedaquiline in the UK were higher than in the US.