Population- versus cohort-based modelling approaches

A systematic review of the modelling and economic evaluation studies assessing regulatory options for e-cigarette use

BACKGROUND

Governments around the world are considering regulating access to nicotine e-cigarettes to prevent uptake among youth however people that smoke tobacco may use them to assist with smoking cessation. The health and cost implications of regulating e-cigarette use among populations are unknown but have been explored in modelling studies. We reviewed health economic evaluation and simulation modelling studies that assessed long-term consequences and interpret their potential usefulness for decision-makers.

METHODS

A systematic review with a narrative synthesis was undertaken. Six databases were searched for modelling studies evaluating population-level e-cigarette control policies or interventions restricting e-cigarette use versus more liberalized use. Studies were required to report the outcomes of life years, quality-adjusted life years (QALYs) and/or healthcare costs. The quality of the studies was assessed using two quality assessment tools.

RESULTS

In total, 15 studies were included with nine for the United States and one each for the United Kingdom, Italy, Australia, Singapore, Canada, and New Zealand. Three studies included cost-utility analyses. Most studies involved health state transition (or Markov) closed cohort models. Many studies had limitations with their model structures, data input quality and transparency, and insufficient analyses handling model uncertainty. Findings were mixed with 11 studies concluding that policies permitting e-cigarette use lead to net benefits and 4 studies concluding net losses in life-years or QALYs and/or healthcare costs.Five studies had industry conflicts of interest.

CONCLUSIONS

While authors did conclude net benefit than net harm in more of the studies so far conducted, the significant limitations that we identified with many of the studies in this review, make it uncertain whether or not countries can expect net population harms or benefits of restrictive versus unrestrictive e-cigarette policies. The generalizability of the findings is limited for decision-makers. In light of the deep uncertainty around the health and economic outcomes of e-cigarettes, simulation modelling methods and uncertainty analyses should be strengthened.

Cost comparison of four venous catheters: Short peripheral catheter, Long peripheral line, Midline, and PICC for peripheral infusion

INTRODUCTION

The use of midline catheters for patients requiring a peripheral IV infusion is sometimes limited by their cost. Although decision trees allow them to be positioned in relation to short peripheral cannulas (SPC), Midlines, and PICCs, their economic impact has not yet been evaluated. A study was conducted to estimate and compare the actual costs of using the three types of catheters for durations of 7, 14, and 21 days.

METHODS

A budget impact analysis compared midlines or mini-midlines/long peripheral cannulas (LPCs) with SPCs and PICCs for typical medical indications excluding indications requiring central line (infusion of irritant or vesicant drugs): treatment of peritonitis over 7 days, cystic fibrosis infection over 14 days, and meningitis over 21 days. A micro-costing study identified resources used during catheter care procedures (consumables, medical/nursing care, examinations, mechanical complications). The cost of remote systemic complications was estimated from the French national cost study. Literature review compared data based on published complication frequencies.

RESULTS

Midline is more economic than the SPC (saving of 39€ over 7 days and 174€ over 14 days), and than the PICC (saving of 102€ over 14 days and 95€ over 21 days).

DISCUSSION

Despite a much higher acquisition cost of the Midline than a SPC, the cost of using a Midline is lower. Although this approach cannot be the only argument for choosing a medical device, it can contribute to it in a tense economic context. The micro-costing has been performed in a center placing PICCline using fluoroscopy for catheter tip positioning. The implantation of a PICC with ECG technique does not require an interventional radiology facility and involves significantly lower logistical and personnel costs. This factor is a limitation in this study. However, even with the use of EGC, the cost difference is in favor of Midline.

Cost-effectiveness analysis of insecticide ban aimed at preventing Parkinson's disease in Central California

BACKGROUND

Our study assessed whether banning specific insecticides to reduce the PD burden in three Central California (CA) counties is cost-effective.

METHOD

We applied a cost-effectiveness analysis using a cohort-based Markov model to estimate the impact and costs of banning seven insecticides that were previously associated with PD in these counties as well as mixture exposures to some of these pesticides. We relied for our estimations on the cohort of 65- and 66-year-olds living in these counties who were unaffected by PD at baseline in 2020 and projected their incidence, costs, and reduction in quality-adjusted-life-years (QALY) loss due to developing PD over a 20-year period. We included a shiny app for modeling different scenarios (https://sherlockli.shinyapps.io/pesticide_pd_economics_part_2/).

RESULTS

According to our scenarios, banning insecticides to reduce the occurrence of PD in three Central CA counties was cost-effective relative to not banning insecticides. In the worst-case scenario of exposure to a single pesticide, methomyl, versus none would result in an estimated 205 (95 % CI: 75, 348) additional PD cases or 12 % (95 % CI: 4 %, 20 %) increase in PD cases over a 20-year period based on residential proximity to pesticide applications. The increase in PD cases due to methomyl would increase health-related costs by $72.0 million (95 % CI: $5.5 million, $187.4 million). Each additional PD patient due to methomyl exposure would incur $109,327 (95 % CI, $5554, $347,757) in costs per QALY loss due to PD. Exposure to methomyl based on workplace proximity to pesticide applications generated similar estimates. The highest PD burden and associated costs would be incurred from exposure to multiple pesticides simultaneously.

CONCLUSION

Our study provides an assessment of the cost-effectiveness of banning specific insecticides to reduce PD burden in terms of health-related QALYs and related costs. This information may help policymakers and stakeholders to make decisions concerning the regulation of pesticides.

Modeling the public health impact of voxelotor in the management of sickle cell disease in France

Sickle cell disease (SCD) is an inherited blood disorder in which sickle hemoglobin (HbS) polymerizes, leading to red blood cell sickling and chronic hemolytic anemia, vaso-occlusive crises, and end-organ damage associated with early mortality. Despite standard of care, patients with SCD still experience complications and early mortality, highlighting remaining unmet treatment needs. Voxelotor is a first-in-class HbS polymerization inhibitor approved by the US Food and Drug Administration as a treatment for SCD and by the European Medicines Agency for hemolytic anemia due to SCD. In clinical studies, voxelotor has been shown to increase hemoglobin (Hb) and decrease hemolytic markers in patients with SCD. The objective of this study was to estimate the impact of voxelotor on the burden of SCD in France using a modeling approach, accounting for its anticipated adoption and diffusion over the next 5 years. We designed a sequential multi-cohort model to project and compare the cumulative incidence of SCD complications over a 20-year time horizon in a world with and without voxelotor. A distribution of patients was simulated across various levels of Hb response based on the phase 3 HOPE trial results, and relative risk reduction was adjusted using published meta-analysis results that projected risk reduction due to a 1 g/dL increase in Hb. In 6100 modeled patients with SCD treated with voxelotor, the model projected the number of deaths to decrease by 39.4%, with an increase of 1.8% in life-years gained. The model also projected life expectancy to increase by 15.8%, and incident cases of stroke, pulmonary hypertension, and chronic kidney disease to decrease by 19.8%, 24.5%, and 25.1%, respectively. The model suggests that improving Hb using a treatment such as voxelotor may have a positive public health impact by reducing the burden of SCD for patients and the healthcare system.

The long-term impact and value of curative therapy for HIV: a modelling analysis

INTRODUCTION

Curative therapies (CTx) to achieve durable remission of HIV disease without the need for antiretroviral therapy (ART) are currently being explored. Our objective was to model the long-term health and cost outcomes of HIV in various countries, the impact of future CTx on those outcomes and the country-specific value-based prices (VBPs) of CTx.

METHODS

We developed a decision-analytic model to estimate the future health economic impacts of a hypothetical CTx for HIV in countries with pre-existing access to ART (CTx+ART), compared to ART alone. We modelled populations in seven low-and-middle-income countries and five high-income countries, accounting for localized ART and other HIV-related costs, and calibrating variables for HIV epidemiology and ART uptake to reproduce historical HIV outcomes before projecting future outcomes to year 2100. Health was quantified using disability-adjusted life-years (DALYs). Base case, pessimistic and optimistic scenarios were modelled for CTx+ART and ART alone. Based on long-term outcomes and each country's estimated health opportunity cost, we calculated the country-specific VBP of CTx.

RESULTS

The introduction of a hypothetical CTx lowered HIV prevalence and prevented future infections over time, which increased life-years, reduced the number of individuals on ART, reduced AIDS-related deaths, and ultimately led to fewer DALYs versus ART-alone. Our base case estimates for the VBP of CTx ranged from $5400 (Kenya) up to $812,300 (United States). Within each country, the VBP was driven to be greater primarily by lower ART coverage, lower HIV incidence and prevalence, and higher CTx cure probability. The VBP estimates were found to be greater in countries where HIV prevalence was higher, ART coverage was lower and the health opportunity cost was greater.

CONCLUSIONS

Our results quantify the VBP for future curative CTx that may apply in different countries and under different circumstances. With greater CTx cure probability, durability and scale up, CTx commands a higher VBP, while improvements in ART coverage may mitigate its value. Our framework can be utilized for estimating this cost given a wide range of scenarios related to the attributes of a given CTx as well as various parameters of the HIV epidemic within a given country.

Predicting the long-term effects of electronic cigarette use on population health: a systematic review of modelling studies

OBJECTIVE

To systematically review and synthesise the findings of modelling studies on the population impacts of e-cigarette use and to identify potential gaps requiring future investigation.

DATA SOURCE AND STUDY SELECTION

Four databases were searched for modelling studies of e-cigarette use on population health published between 2010 and 2023. A total of 32 studies were included.

DATA EXTRACTION

Data on study characteristics, model attributes and estimates of population impacts including health outcomes and smoking prevalence were extracted from each article. The findings were synthesised narratively.

DATA SYNTHESIS

The introduction of e-cigarettes was predicted to lead to decreased smoking-related mortality, increased quality-adjusted life-years and reduced health system costs in 29 studies. Seventeen studies predicted a lower prevalence of cigarette smoking. Models that predicted negative population impacts assumed very high e-cigarette initiation rates among non-smokers and that e-cigarette use would discourage smoking cessation by a large margin. The majority of the studies were based on US population data and few studies included factors other than smoking status, such as jurisdictional tobacco control policies or social influence.

CONCLUSIONS

A population increase in e-cigarette use may result in lower smoking prevalence and reduced burden of disease in the long run, especially if their use can be restricted to assisting smoking cessation. Given the assumption-dependent nature of modelling outcomes, future modelling studies should consider incorporating different policy options in their projection exercises, using shorter time horizons and expanding their modelling to low-income and middle-income countries where smoking rates remain relatively high.

The Economic Value of Rotavirus Vaccination When Optimally Implemented in a High-Income Country

Rotavirus vaccination was introduced in high-income countries starting in 2006, with no recommendation for optimal implementation. Economic evaluations were presented before launch projecting potential impacts. Few economic reassessments have been reported following reimbursement. This study compares the short- to long-term economic value of rotavirus vaccination between pre-launch predictions and real-world evidence collected over 15 years, proposing recommendations for optimal vaccine launch. A cost-impact analysis compared rotavirus hospitalisation data after the introduction of vaccination between pre-launch modelled projections and observed data collected in the RotaBIS study in Belgium. A best model fit of the observed data was used to simulate launch scenarios to identify the optimal strategy. Data from other countries in Europe were used to confirm the potential optimal launch assessment. The Belgian analysis in the short term (first 8 years) indicated a more favourable impact for the observed data than predicted pre-launch model results. The long-term assessment (15 years) showed bigger economic disparities in favour of the model-predicted scenario. A simulated optimal vaccine launch, initiating the vaccination at least 6 months prior the next seasonal disease peak with an immediate very high vaccine coverage, indicated important additional potential gains, which would make vaccination very cost impactful. Finland and the UK are on such a route leading to long-term vaccination success, whereas Spain and Belgium have difficulties in achieving optimum vaccine benefits. An optimal launch of rotavirus vaccination may generate substantial economic gains over time. For high-income countries that are considering implementing rotavirus vaccination, achieving an optimal launch is a critical factor for long-term economic success.

Impact of Expanding Eligibility Criteria for Cochlear Implantation - Dynamic Modeling Study

OBJECTIVES

Eligibility criteria for cochlear implantation (CI) are shifting due to technological and surgical improvements. The aim of this study was to explore the impact of further expanding unilateral CI criteria in those with severe hearing loss (HL) (61-80 dBHL) in terms of number of CI recipients, costs, quality of life, and cost-effectiveness.

METHODS

A dynamic population-based Markov model was constructed mimicking the Dutch population in three age categories over a period of 20 years. Health states included severe HL (61-80 dBHL), profound HL (>81 dBHL), CI recipients, and no-CI recipients. Model parameters were based on published literature, (national) databases, expert opinion, and model calibration.

RESULTS

If persons with severe HL would qualify and opt for CI similar to those with profound HL now, this would lead to a 6-7 times increase of new CI recipients and an associated increase in costs (€550 million) and QALYs (54.000) over a 20-year period (incremental cost utility ratio: 10.771 euros/QALY [2.5-97.5 percentiles: 1.252-23.171]). One-way-sensitivity analysis indicated that model outcomes were most sensitive to regaining employment, utility associated with having a CI, and costs of surgery and testing.

CONCLUSION

Our findings suggest that expanding eligibility for CI to persons with severe HL could be a cost-effective use of resources. Clearly, however, it would require a significant increase in diagnostic, operative, and rehabilitative capacity. Our quantitative estimates can serve as a basis for a wider societal deliberation on the question whether such an increase can and should be pursued.

LEVEL OF EVIDENCE

NA Laryngoscope, 133:924-932, 2023.

Cost-Effectiveness, Burden of Disease and Budget Impact of Inclisiran: Dynamic Cohort Modelling of a Real-World Population with Cardiovascular Disease

OBJECTIVE

We aimed to estimate the cost-effectiveness, burden of disease and budget impact of inclisiran added to standard-of-care lipid-lowering therapy in the real-world secondary cardiovascular prevention population in Switzerland.

METHODS

An open-cohort Markov model captured event risks by sex, age and low-density lipoprotein cholesterol based on epidemiological and real-world data. Low-density lipoprotein cholesterol reduction with add-on inclisiran was based on trial results and translated to meta-analysis-based relative risks of cardiovascular events. Unit costs for 2018 were based on publicly available sources, adopting a Swiss healthcare system perspective. Price assumptions of Swiss francs (CHF) 500 and CHF 3,000 per dose of inclisiran were evaluated, combined with uptake assumptions for burden of disease and budget impact. The assessment of cost-effectiveness used a discount rate of 3% per year. We performed deterministic and probabilistic sensitivity analyses, and extensive scenario analyses.

RESULTS

Patients treated with inclisiran gained a 0.291 qualityadjusted life-year at an incremental cost per QALY gained of CHF 21,107/228,040 (life-long time horizon, discount rate 3%) under the lower/higher price. Inclisiran prevented 1025 cardiovascular deaths, 3425 acute coronary syndrome episodes, and 1961 strokes in 48,823 patients ever treated during 10 years; the 5-year budget impact was CHF 49.3/573.4 million under the lower/higher price. Estimates were sensitive to calibration targets and treatment eligibility; burden of disease/budget impact results also to uptake. Limitations included uncertainties about model assumptions and the size and characteristics of the population modelled.

CONCLUSIONS

Inclisiran may be cost-effective at a willingness to pay of CHF 30,000 if priced at CHF 500; a threshold upwards of CHF 250,000 will be required if priced at CHF 3000. Inclisiran could enable important reductions in cardiovascular burden particularly under broader eligibility with a budget impact range from moderate to high depending on price.

Cost and health impact analysis of herpes zoster vaccination in Norway

BACKGROUND

A decision analytic model was developed to estimate the cost-effectiveness of a national vaccination program against herpes zoster in Norway.

METHODS

The model analyzed six vaccination scenarios that included the live-attenuated zoster vaccine under different target ages of vaccination (60, 65, and 70 years) compared with no vaccination. A catch-up program implemented in the first year of the vaccination was included in three of the scenarios. The model followed the population of Norway over a 40-year time horizon to estimate costs and outcomes associated with vaccination. Immunization costs, costs related to herpes zoster (both healthcare sector and non-healthcare sector), the quality of life gains due to avoided cases of herpes zoster, and quality-of-life losses due to vaccine-related adverse events were estimated.

RESULTS AND CONCLUSIONS

A national vaccination program would result in reduction of the number of herpes zoster cases and decreased burden of illness. Vaccinating adults at 65 years of age with catch-up up to 70 years in the first year of the program was the most cost-effective strategy with the incremental cost per quality-adjusted life-year gained at NOK (Norwegian Krone) 245,459 from the societal perspective and NOK 248,637 from the health care system perspective.

Economic Analysis of Vaccination Programs: An ISPOR Good Practices for Outcomes Research Task Force Report

This report provides recommendations for budget holders and decision makers in high-, middle, and low-income countries requiring economic analyses of new vaccination programs to allocate scarce resources given budget constraints. ISPOR's Economic Evaluation of Vaccines Designed to Prevent Infectious Disease: Good Practices Task Force wrote guidelines for three analytic methods and solicited comments on them from external reviewers. Cost-effectiveness analyses use decision-analytic models to estimate cumulative changes in resource use, costs, and changes in quality- or disability-adjusted life-years attributable to changes in disease outcomes. Constrained optimization modeling uses a mathematical objective function to be optimized (e.g. disease cases avoided) for a target population for a set of interventions including vaccination programs within established constraints. Fiscal health modeling estimates changes in net present value of government revenues and expenditures attributable to changes in disease outcomes. The task force recommends that those designing economic analyses for new vaccination programs take into account the decision maker's policy objectives and country-specific decision context when estimating: uptake rate in the target population; vaccination program's impact on disease cases in the population over time using a dynamic transmission epidemiologic model; vaccination program implementation and operating costs; and the changes in costs and health outcomes of the target disease(s). The three approaches to economic analysis are complementary and can be used alone or together to estimate a vaccination program's economic value for national, regional, or subregional decision makers in high-, middle-, and low-income countries.

Smoking Cessation: A Comparison of Two Model Structures

BACKGROUND

Most economic evaluations of smoking cessation interventions have used cohort state-transition models. Discrete event simulations (DESs) have been proposed as a superior approach.

OBJECTIVE

We developed a state-transition model and a DES using the discretely integrated condition event (DICE) framework and compared the cost-effectiveness results. We performed scenario analysis using the DES to explore the impact of alternative assumptions.

METHODS

The models estimated the costs and quality-adjusted life years (QALYs) for the intervention and comparator from the perspective of the UK National Health Service and Personal Social Services over a lifetime horizon. The models considered five comorbidities: chronic obstructive pulmonary disease, myocardial infarction, coronary heart disease, stroke and lung cancer. The state-transition model used prevalence data, and the DES used incidence. The costs and utility inputs were the same between two models and consistent with those used in previous analyses for the National Institute for Health and Care Excellence.

RESULTS

In the state-transition model, the intervention produced an additional 0.16 QALYs at a cost of £540, leading to an incremental cost-effectiveness ratio (ICER) of £3438. The comparable DES scenario produced an ICER of £5577. The ICER for the DES increased to £18,354 when long-term relapse was included.

CONCLUSIONS

The model structures themselves did not influence smoking cessation cost-effectiveness results, but long-term assumptions did. When there is variation in long-term predictions between interventions, economic models need a structure that can reflect this.

Is adding maternal vaccination to prevent whooping cough cost-effective in Australia?

Pertussis or whooping cough, a highly infectious respiratory infection, causes significant morbidity and mortality in infants. In adolescents and adults, pertussis presents with atypical symptoms often resulting in under-diagnosis and under-reporting, increasing the risk of transmission to more vulnerable groups. Maternal vaccination against pertussis protects mothers and newborns. This evaluation assessed the cost-effectiveness of adding maternal dTpa (reduced antigen diphtheria, Tetanus, acellular pertussis) vaccination to the 2016 nationally-funded pertussis program (DTPa [Diphtheria, Tetanus, acellular Pertussis] at 2, 4, 6, 18 months, 4 years and dTpa at 12–13 years) in Australia.

A static cross-sectional population model was developed using a one-year period at steady-state. The model considered the total Australian population, stratified by age. Vaccine effectiveness against pertussis infection was assumed to be 92% in mothers and 91% in newborns, based on observational and case-control studies. The model included conservative assumptions around unreported cases.

With 70% coverage, adding maternal vaccination to the existing pertussis program would prevent 8,847 pertussis cases, 422 outpatient cases, 146 hospitalizations and 0.54 deaths per year at the population level. With a 5% discount rate, 138.5 quality-adjusted life-years (QALYs) would be gained at an extra cost of AUS$ 4.44 million and an incremental cost-effectiveness ratio of AUS$ 32,065 per QALY gained. Sensitivity and scenario analyses demonstrated that outcomes were most sensitive to assumptions around vaccine effectiveness, duration of protection in mothers, and disutility of unreported cases.

In conclusion, dTpa vaccination in the third trimester of pregnancy is likely to be cost-effective from a healthcare payer perspective in Australia.

Estimating the cost-effectiveness of a sequential pneumococcal vaccination program for adults in Germany

Introduction

In Germany, a 23-valent polysaccharide pneumococcal vaccine (PPSV23) is recommended for elderly (60+) and patients 16+ with chronic diseases not associated with immune suppression. For all other patients at risk, sequential immunization with a 13-valent pneumococcal conjugate vaccine (PCV13) first, followed by PPSV23 is recommended. Repeated vaccination with PPSV23 is recommended every 6 years after individual assessment by the physician. This was adopted into the vaccination directive with binding reimbursement and funding. However, additional voluntary services allow statutory health insurances to differentiate from each other. Aim of this study is to estimate the cost-effectiveness of voluntary service scenarios compared to the strategy in place to support informed decision making.

Methods

A microsimulation framework with Markov-type process of a population susceptible to pneumococcal disease over a lifetime horizon was developed to compare effectiveness and cost-effectiveness of different vaccination strategies. We simulated 1,000 iterations for seven scenarios. Assumptions were derived from published literature and probabilistic sensitivity analysis was run to show the robustness of the model.

Results

Our study indicates that all voluntary service strategies could prevent further clinical cases compared to the existing policy. Depending on the scenario, 48–142 invasive pneumococcal disease (IPD), 24,000–45,000 hospitalized all-cause nonbacteremic pneumonia (NBP), 15,000–45,000 outpatient NBP cases, and 4,000–8,000 deaths could be avoided on average. This refers to potential savings of €115 Mio. - €187 Mio. for medical and non-medical costs. Additional costs per patient for the payer are €2.48 to €7.13 and for the society €2.20 to €6.85. The ICER per LYG ranged from €3,662 to €23,061 (payer) and €3,258 to €29,617 (societal). All but one scenario was cost-effective in ≥60% of the generated 1,000 simulations.

Conclusion

Compared to the vaccination strategy in place, the different hypothetical scenarios can be considered cost-effective and suitable as additional voluntary services.

Optimising the introduction of multiple childhood vaccines in Japan: A model proposing the introduction sequence achieving the highest health gains

BACKGROUND

Many countries struggle with the prioritisation of introducing new vaccines because of budget limitations and lack of focus on public health goals. A model has been developed that defines how specific health goals can be optimised through immunisation within vaccination budget constraints.

METHODS

Japan, as a country example, could introduce 4 new pediatric vaccines targeting influenza, rotavirus, pneumococcal disease and mumps with known burden of disease, vaccine efficacies and maximum achievable coverages. Operating under budget constraints, the Portfolio-model for the Management of Vaccines (PMV) identifies the optimal vaccine ranking and combination for achieving the maximum QALY gain over a period of 10 calendar years in children <5 years old. This vaccine strategy, of interest and helpful for a healthcare decision maker, is compared with an unranked vaccine selection process.

RESULTS

Results indicate that the maximum QALY gain with a fixed annual vaccination budget of 500 billion Japanese Yen over a 10-year period is 72,288 QALYs using the optimal sequence of vaccine introduction (mumps [1st], followed by influenza [2nd], rotavirus [3rd], and pneumococcal [4th]). With exactly the same budget but without vaccine ranking, the total QALY gain can be 20% lower.

CONCLUSION

The PMV model could be a helpful tool for decision makers in those environments with limited budget where vaccines have to be selected for trying to optimise specific health goals.

3. How comprehensive can we be in the economic assessment of vaccines?

In two previous papers we argued on current vaccines economic assessment not fully comprehensive when using the incremental cost-utility analysis normally applied for treatments. Many differences exist between vaccines and drug treatments making vaccines economic evaluation more cumbersome. Four challenges overwhelmingly present in vaccines assessment are less important for treatments: requirements for population, societal perspectives, budget impact evaluation, and time focused objectives (control or elimination). Based on this, economic analysis of vaccines may need to be presented to many different stakeholders with various evaluation preferences, in addition to the current stakeholders involved for drugs treatment assessment. Then, we may need a tool making the inventory of the different vaccines health economic assessment programmes more comprehensive. The cauliflower value toolbox has been developed with that aim, and its use is illustrated here with rotavirus vaccine. Given the broader perspectives for vaccine assessment, it provides better value and cost evaluations. Cost-benefit analysis may be the preferred economic assessment method when considering substitution from treatment to active medical prevention. Other economic evaluation methods can be selected (i.e. optimisation modelling, return on investment) when project prioritisation is the main focus considered and when stakeholders would like to influence the development of the healthcare programme.

Ecological validity of cost-effectiveness models of universal HPV vaccination: A systematic literature review

BACKGROUND

The protective (herd) effect of the selective vaccination of pubertal girls against human papillomavirus (HPV) implies a high probability that one of the two partners involved in intercourse is immunised, hence preventing the other from this sexually transmitted infection. The dynamic transmission models used to inform immunisation policy should include consideration of sexual behaviours and population mixing in order to demonstrate an ecological validity, whereby the scenarios modelled remain faithful to the real-life social and cultural context. The primary aim of this review is to test the ecological validity of the universal HPV vaccination cost-effectiveness modelling available in the published literature.

METHODS

The research protocol related to this systematic review has been registered in the International Prospective Register of Systematic Reviews (PROSPERO: CRD42016034145). Eight published economic evaluations were reviewed.

RESULTS

None of the studies showed due consideration of the complexities of human sexual behaviour and the impact this may have on the transmission of HPV.

DISCUSSION

Our findings indicate that all the included models might be affected by a different degree of ecological bias, which implies an inability to reflect the natural demographic and behavioural trends in their outcomes and, consequently, to accurately inform public healthcare policy. In particular, ecological bias have the effect to over-estimate the preference-based outcomes of selective immunisation. A relatively small (15-20%) over-estimation of quality-adjusted life years (QALYs) gained with selective immunisation programmes could induce a significant error in the estimate of cost-effectiveness of universal immunisation, by inflating its incremental cost effectiveness ratio (ICER) beyond the acceptability threshold. The results modelled here demonstrate the limitations of the cost-effectiveness studies for HPV vaccination, and highlight the concern that public healthcare policy might have been built upon incomplete studies.

The Sustained Rotavirus Vaccination Impact on Nosocomial Infection, Duration of Hospital Stay, and Age: The RotaBIS Study (2005-2012)

Introduction

The benefits of rotavirus (RV) vaccination in developed countries have focused on reductions in mortality, hospitalization and medical visits, and herd protection. We investigated other aspects related to RV-induced nosocomial infection, duration of hospital stay, age shift, and sustained vaccine impact (VI) over time.

Method

RotaBIS (Rotavirus Belgian Impact Study; ClinicalTrials.gov identifier, NCT01563146) annually collects retrospective data on hospitalization linked to RV testing in children up to 5 years old from 11 pediatric wards located all over Belgium. Data from 2005 to 2012 have been split in pre- (2005–2006) and post-vaccination (2007–2012) period. Information was collected on age, gender, RV test result, nosocomial infection caused by RV and duration of hospital stay.

Results

Over the 6-year period after the introduction of the RV vaccine, an 85% reduction in nosocomial infections was observed (221 in 2005 to 33 in 2012, p < 0.001). A significant reduction of almost 2 days in average duration of hospital stay per event was observed overall (7.62 days in 2005 to 5.77 days in 2012, p < 0.001). The difference is mainly explained by the higher reduction in number of nosocomial infections. A pronounced age shift (+24%, p < 0.01) of RV nosocomial infection to infants ≤2 months old was observed, increasing with length of post-vaccination period. VI was maintained over the follow-up (±79% VI per birth cohort). A decrease was seen depending on age, 85% (95% CI 76–91%) in the youngest to 63% (95% CI 22–92%) in the oldest age group.

Conclusion

The higher reduction in nosocomial infection may affect the overall average duration of hospital stay for RV infection. No change in VI by birth cohort, but a reduction by age group was observed. These findings could be important for decision-makers considering the introduction of universal mass RV vaccination programs.

Trial registration

ClinicalTrials.gov identifier, NCT01563146.

Funding

GlaxoSmithKline Biologicals SA (Rixensart, Belgium).

Economic evaluation of the breast cancer screening programme in the Basque Country: retrospective cost-effectiveness and budget impact analysis

Background

Breast cancer screening in the Basque Country has shown 20 % reduction of the number of BC deaths and an acceptable overdiagnosis level (4 % of screen detected BC). The aim of this study was to evaluate the breast cancer early detection programme in the Basque Country in terms of retrospective cost-effectiveness and budget impact from 1996 to 2011.

Methods

A discrete event simulation model was built to reproduce the natural history of breast cancer (BC). We estimated for lifetime follow-up the total cost of BC (screening, diagnosis and treatment), as well as quality-adjusted life years (QALY), for women invited to participate in the evaluated programme during the 15-year period in the actual screening scenario and in a hypothetical unscreened scenario. An incremental cost-effectiveness ratio was calculated with the use of aggregated costs. Besides, annual costs were considered for budget impact analysis. Both population level and single-cohort analysis were performed. A probabilistic sensitivity analysis was applied to assess the impact of parameters uncertainty.

Results

The actual screening programme involved a cost of 1,127 million euros and provided 6.7 million QALYs over the lifetime of the target population, resulting in a gain of 8,666 QALYs for an additional cost of 36.4 million euros, compared with the unscreened scenario. Thus, the incremental cost-effectiveness ratio was 4,214€/QALY. All the model runs in the probabilistic sensitivity analysis resulted in an incremental cost-effectiveness ratio lower than 10,000€/QALY. The screening programme involved an increase of the annual budget of the Basque Health Service by 5.2 million euros from year 2000 onwards.

Conclusions

The BC screening programme in the Basque Country proved to be cost-effective during the evaluated period and determined an affordable budget impact. These results confirm the epidemiological benefits related to the centralised screening system and support the continuation of the programme.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2386-y) contains supplementary material, which is available to authorized users.

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.

Medium- to Long-Term Impact of Rotavirus Vaccination on Hospital Care in Belgium: A 7-Year Follow-Up of the Rotavirus Belgium Impact Study (RotaBIS)

Introduction

Rotavirus (RV) vaccination was introduced in Belgium in 2006. With the high uptake it had (>85%), a sharp decline in hospitalizations was observed during the first years after vaccine introduction. The objective of this study was to investigate whether this decline was maintained and to simulate projections.

Methods

The Rotavirus Belgium Impact Study allowed an analysis of the RV vaccine impact amongst children in 11 hospitals in Belgium over a 9-year period (2005–2013) with 2 years pre- and 7 years post-vaccine introduction. Results were compared by year and by subsequent birth cohort aging up to 5 years. The two different analysis methods helped dismantling the different (direct and indirect) effects of vaccine protection to simulate future hospitalization trends.

Results

During the whole observation period, 40,552 RV detection tests were performed of which 5832 were positive (14.4%). After RV vaccine introduction, a significant reduction in number of tests performed (−38%) was combined with a dramatic drop in numbers of positive tests (−76.6%). The decreases were spectacular during the first two years of vaccine introduction; after that period, the decrease flattened. Cross-sectional comparison with cohort data showed that the initial drop was heavily influenced by the herd effect of the vaccine. Cohort analysis demonstrated a low rate of residual disease over time, suggesting another infection source other than the child population.

Conclusion

The residual disease will be maintained in the community when a same vaccination strategy is continued over time, starting vaccination of children only at 6 weeks’ time.

Funding

GlaxoSmithKline Biologicals SA.

Trial registration

ClinicalTrials.gov identifier, NCT01563146.

Electronic supplementary material

The online version of this article (doi:10.1007/s40121-015-0099-1) contains supplementary material, which is available to authorized users.

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.

Public health impact and cost-effectiveness of dairy products supplemented with vitamin D in prevention of osteoporotic fractures

Background

Dietary sources of calcium and vitamin D are recommended as a first-line strategy in prevention of osteoporosis-related fractures but their public health and economic impact has never been studied.

Methods

We designed a population-based model to forecast the potential health outcomes and medical effectiveness of the daily administration of dairy supplements containing 800 IU of vitamin D and 1 g of calcium in cohorts of subjects, from both genders, aged 50, 60, 70 and 80 years. Annual costs of dairy products were tested at €150, €250 and €350.

Results

In total, the daily intake of vitamin-D rich dairy products reduces by 30,376 and 16,105 events the number of osteoporotic fractures in women and men respectively and permits to gain 6605 and 6144 life-years, in women and men respectively. This intervention is cost-effective from 70 years on in the general population and from 60 years on in patients at increased risk of osteoporotic fractures.

Conclusion

The recommendation to use dairy products as the preferred source of calcium and vitamin D in aging males and females is supported by public health and health economic analyses.

Electronic supplementary material

The online version of this article (doi:10.1186/s13690-015-0099-3) contains supplementary material, which is available to authorized users.

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.

Economic evaluations with agent-based modelling: an introduction

Agent-based modelling (ABM) is a relatively new technique, which overcomes some of the limitations of other methods commonly used for economic evaluations. These limitations include linearity, homogeneity and stationarity. Agents in ABMs are autonomous entities, who interact with each other and with the environment. ABMs provide an inductive or 'bottom-up' approach, i.e. individual-level behaviours define system-level components. ABMs have a unique property to capture emergence phenomena that otherwise cannot be predicted by the combination of individual-level interactions. In this tutorial, we discuss the basic concepts and important features of ABMs. We present a case study of an application of a simple ABM to evaluate the cost effectiveness of screening of an infectious disease. We also provide our model, which was developed using an open-source software program, NetLogo. We discuss software, resources, challenges and future research opportunities of ABMs for economic evaluations.

Cost-effectiveness of natalizumab in multiple sclerosis: an updated systematic review

As natalizumab (Tysabri; Elan Pharmaceuticals, Inc., Dublin, Ireland) and other disease-modifying drugs are entering the market for multiple sclerosis, the treatment repertoire is expanding beyond the established first-line treatments. This is creating new opportunities but also increasing the uncertainty in the appropriate management of this condition with its considerable societal burden. As a result, economic evaluations are increasingly influential in healthcare decision making. Seven evaluations that included natalizumab have been published to date. They largely report favorable results for this treatment compared with other drugs. However, the models used to reach these conclusions have been subjected to significant debate, owing to limited data availability as well as the methodological complexities and uncertainties in the pharmacoeconomics of multiple sclerosis. This review critically discusses the available evidence based on the cost-effectiveness of natalizumab and uses the data to explain more general issues in the evaluation of similar drugs. The review also suggests how shortcomings in current studies may potentially be addressed in the future.

Economic evaluation of vaccines: specificities and future challenges illustrated by recent European examples

This study reviews the current challenges in the economic evaluation of vaccines with a focus on European countries. In particular, the type of clinical evidence generally available, the impact of discounting for time preference and the use of modeling to derive valid cost-effectiveness assessments are considered. First, the characteristics of evidence for vaccines are discussed, as well as potential difficulties faced when using evidence-based medicine applied to curative drugs to interpret vaccine evidence. Then, discounting is considered and specific examples illustrating issues with different types of discounting are described, taking HPV as the example. Finally, the need for sometimes complex dynamic models for vaccines is explored, and specific types of models are reviewed, keeping into consideration the adage "complex when needed, straightforward if allowed."

Budget impact analysis of first-line treatment with pazopanib for advanced renal cell carcinoma in Spain

Background

Due to economic constraints, cancer therapies are under close scrutiny by clinicians, pharmacists and payers alike. There is no published pharmacoeconomic evidence guiding the choice of first-line therapy for advanced renal cell carcinoma (RCC) in the Spanish setting. We aimed to develop a model describing the natural history of RCC that can be used in healthcare decision-making. We particularly analyzed the budget impact associated with the introduction of pazopanib compared to sunitinib under the Spanish National Healthcare System (NHS) perspective.

Methods

We developed a Markov model to estimate the future number of cases of advanced RCC (patients with favorable or intermediate risk) resulting either from initial diagnosis or disease progression after surgery. The model parameters were obtained from the literature. We assumed that patients would receive either pazopanib or sunitinib as first-line therapy until disease progression. Pharmacological costs and costs associated with the management of adverse events (AE) were considered. A univariate sensitivity analysis was undertaken in order to test the robustness of the results.

Results

The model predicted an adult RCC prevalence of 7.5/100,000 (1-year), 20.7/100,000 (3-year) and 32.5/100,000 (5-year). These figures are very close to GLOBOCAN reported RCC prevalence estimates of 7.6/100,000, 20.2/100,000 and 31.1/100,000, respectively. The model predicts 1,591 advanced RCC patients with favorable or intermediate risk in Spain in 2013. Annual per patient pharmacological costs were €32,365 and €39,232 with pazopanib and sunitinib, respectively. Annual costs associated with the management of AE were €662 and €974, respectively. Overall annual per patient costs were €7,179 (18%) lower with pazopanib compared to sunitinib. For every point increase in the percentage of patients treated with pazopanib, the NHS would save €67,236. If all the 1,591 patients predicted were treated with pazopanib, the NHS would save €6,723,622 in 2013. Results were robust according to the sensitivity analysis.

Conclusions

We developed a model that accurately reproduces the natural history of RCC and can be thus used in healthcare decision-making. When applied to the Spanish case, the introduction of pazopanib results in savings for the NHS, as a consequence of both reduced pharmacological costs and lower costs associated with the management of AE compared to sunitinib.

Economics of vaccines revisited

Performing a total health economic analysis of a vaccine newly introduced into the market today is a challenge when using the conventional cost-effectiveness analysis we normally apply on pharmaceutical products. There are many reasons for that, such as: the uncertainty in the total benefit (direct and indirect) to be measured in a population when using a cohort model; (1) appropriate rules about discounting the long-term impact of vaccines are absent jeopardizing therefore their value at the initial investment; (2) the presence of opposite contexts when introducing the vaccine in developed vs. the developing world with high benefits, low initial health care investment for the latter vs. marginal benefit and high cost for the former; with a corresponding paradox for the vaccine becoming very cost-effective in low income countries but rather medium in middle low to high middle income countries; (3) and the type of trial assessment for the newer vaccines is now often performed with immunogenicity reaction instead of clinical endpoints which still leaves questions on their real impact and their head-to-head comparison. (4.)