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1.
J Glob Health ; 12: 04043, 2022 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-35796158

RESUMO

Background: Hepatitis B virus (HBV) infection is a leading public health problem in China. COVID-19 pandemic has interrupted the delivery of health care interventions worldwide, including HBV infection control. Methods: In this study, we used a Markov model to quantify the costs and population health impact of HBV treatment in China for the following scenarios: 1) current practice with only 17% of treatment eligible HBV infected adults receiving antiviral treatment; 2) reaching the World Health Organization (WHO) treatment target of 80% by 2030 with a steady increase in treatment rate beginning in 2022; and 3) the effect of a 1-5-year delay in meeting the 2030 WHO treatment target. A one-way as well as a probabilistic sensitivity analysis were conducted. Results: Without increasing antiviral treatment for treatment eligible HBV infected adults, the life-time health care costs for the estimated 89.2 million adults living with HBV in China is US$1305 billion and 10.8 million (12%) will die from HBV-related liver disease. Increasing treatment to achieve the WHO 80% target by 2030 would save US$472 billion and prevent 3.3 million HBV-related deaths. We estimated that a 1-year delay beyond 2030 in reaching the WHO 80% treatment target would likely lead to US$55 billion increase in future health care costs, and an additional 334 000 future deaths from HBV-related liver disease or cancer. Conclusions: Reaching the WHO 2030 with minimal delays would have an immense health and economic benefit. Implementing a national treatment program for HBV in China should be a key priority for policymakers.


Assuntos
COVID-19 , Hepatite B , Antivirais/uso terapêutico , China/epidemiologia , Hepatite B/tratamento farmacológico , Hepatite B/epidemiologia , Humanos , Pandemias
2.
Sex Transm Dis ; 49(7): 517-525, 2022 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-35312661

RESUMO

BACKGROUND: The estimated number of people living with hepatitis B virus (HBV) infection acquired through sexual transmission was 103,000 in 2018, with an estimated incidence of 8300 new cases per year. Although hepatitis B (HepB) vaccination is recommended by the Advisory Committee for Immunization Practices for persons seeking evaluation and treatment for sexually transmitted infections (STIs), prevaccination testing is not yet recommended. Screening may link persons with chronic hepatitis B to care and reduce unnecessary vaccination. METHODS: We used a Markov model to calculate the health impact and cost-effectiveness of 1-time HBV testing combined with the first dose of the HepB vaccine for adults seeking care for STI. We ran a lifetime, societal perspective analysis for a hypothetical population of 100,000 aged 18 to 69 years. The disease progression estimates were taken from recent cohort studies and meta-analyses. In the United States, an intervention that costs less than $100,000 per quality-adjusted life-year (QALY) is generally considered cost-effective. The strategies that were compared were as follows: (1) vaccination without HBV screening, (2) vaccination and hepatitis B surface antigen (HBsAg) screening, (3) vaccination and screening with HBsAg and anti-HBs, and (4) vaccination and screening with HBsAg, anti-HBs, and anti-HBc. Data were obtained from Centers for Medicare & Medicaid services reimbursement, the Centers for Disease Control and Prevention vaccine price list, and additional cost-effectiveness literature. RESULTS: Compared with current recommendations, the addition of 1-time HBV testing is cost-saving and would prevent an additional 138 cases of cirrhosis, 47 cases of decompensated cirrhosis, 90 cases of hepatocellular carcinoma, 33 liver transplants, and 163 HBV-related deaths, and gain 2185 QALYs, per 100,000 adults screened. Screening with the 3-test panel would save $41.6 to $42.7 million per 100,000 adults tested compared with $41.5 to $42.5 million for the 2-test panel and $40.2 to $40.3 million for HBsAg alone. CONCLUSIONS: One-time HBV prevaccination testing in addition to HepB vaccination for unvaccinated adults seeking care for STI would save lives and prevent new infections and unnecessary vaccination, and is cost-saving.


Assuntos
Hepatite B , Infecções Sexualmente Transmissíveis , Adulto , Idoso , Análise Custo-Benefício , Hepatite B/diagnóstico , Hepatite B/epidemiologia , Hepatite B/prevenção & controle , Antígenos de Superfície da Hepatite B , Vacinas contra Hepatite B , Vírus da Hepatite B , Humanos , Cirrose Hepática , Medicare , Infecções Sexualmente Transmissíveis/diagnóstico , Infecções Sexualmente Transmissíveis/epidemiologia , Infecções Sexualmente Transmissíveis/prevenção & controle , Estados Unidos/epidemiologia , Vacinação
3.
Clin Infect Dis ; 74(2): 210-217, 2022 01 29.
Artigo em Inglês | MEDLINE | ID: mdl-33956937

RESUMO

BACKGROUND: An estimated 862 000 to 2.4 million people have chronic hepatitis B infection (CHB). Hepatitis B screening is recommended for pregnant women and populations with increased CHB risk. However, diagnosis rates remain low, with only 33% of people with CHB aware of their infection. This study aimed to assess the cost-effectiveness of universal adult screening for CHB. METHODS: We used a Markov model to calculate the costs, population health impact, and cost-effectiveness of 1-time universal screening and CHB monitoring and treatment compared with current practice. Sensitivity analysis was performed on model parameters to identify thresholds for cost-saving or cost-effectiveness based on a willingness to pay of $50 000/quality-adjusted life-year. The analysis assumed testing would be performed during routine healthcare visits and that generic tenofovir or entecavir would be dispensed for treatment. Testing costs were based on Medicare reimbursement rates. RESULTS: At an estimated 0.24% prevalence of undiagnosed CHB, universal hepatitis B surface antigen (HBsAg) screening in adults aged 18-69 years is cost-saving compared with current practice if antiviral treatment drug costs remain below $894/year. Compared with current practice, universal screening would avert an additional 7.4 cases of compensated cirrhosis, 3.3 cases of decompensated cirrhosis, 5.5 cases of hepatocellular carcinoma, 1.9 liver transplants, and 10.3 hepatitis B virus-related deaths at a saving of $263 000/100 000 adults screened. CONCLUSIONS: Universal HBsAg screening of adults in the US general population for CHB is cost-effective and likely cost-saving compared with current CHB screening recommendations.


Assuntos
Hepatite B Crônica , Neoplasias Hepáticas , Adolescente , Adulto , Idoso , Antivirais/uso terapêutico , Análise Custo-Benefício , Feminino , Hepatite B Crônica/diagnóstico , Hepatite B Crônica/tratamento farmacológico , Hepatite B Crônica/epidemiologia , Humanos , Medicare , Pessoa de Meia-Idade , Gravidez , Anos de Vida Ajustados por Qualidade de Vida , Estados Unidos/epidemiologia , Adulto Jovem
4.
Liver Int ; 42(1): 16-25, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34328697

RESUMO

BACKGROUND & AIMS: We aim to capture the economic impact of a potential cure for chronic hepatitis B infection (CHB) in three countries (USA, China and Australia) with different health systems and epidemics to estimate the threshold drug prices below which a CHB cure would be cost-saving and/or highly cost-effective. METHODS: We simulated patients' hepatitis B progression, under three scenarios: current long-term suppressive antiviral therapy, functional cure defined as sustained undetectable HBsAg and HBV DNA, and partial cure defined as sustained undetectable HBV DNA only after a finite, 48-week treatment. RESULTS: Compared with current long-term antiviral therapy, a 30% effective functional cure among patients with and without cirrhosis in the USA, China and Australia would yield 17.50, 17.32 and 20.42 QALYs per patient, and 20.61, 20.42 and 20.62 QALYs per patient respectively. In financial terms, for CHB patients with and without cirrhosis, this would be cost-saving at a one-time treatment cost under US$11 944 and US$6694, respectively, in the USA, US$1744 and US$1001 in China, and US$12 063 and US$10 983 in Australia. CONCLUSION: We show that in purely economic terms, a CHB cure will be highly cost-effective even if effective in only 30% of treated patients. The threshold price for cure is largely determined by the current antiviral drug costs, since it will replace a daily antiviral pill that is inexpensive and effective, although not curative. The likely need for combination therapies to achieve cure will also present cost challenges. While cost-effectiveness is important, it cannot be the only consideration, as cure will provide many benefits in addition to reduced liver disease and HCC, including eliminating the need for a long-term daily pill and reducing stigma often associated with chronic viral infection.


Assuntos
Carcinoma Hepatocelular , Hepatite B Crônica , Hepatite B , Neoplasias Hepáticas , Antivirais , Austrália , Carcinoma Hepatocelular/tratamento farmacológico , China/epidemiologia , Análise Custo-Benefício , Hepatite B/tratamento farmacológico , Hepatite B Crônica/tratamento farmacológico , Humanos , Neoplasias Hepáticas/tratamento farmacológico
5.
Value Health ; 23(12): 1552-1560, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33248510

RESUMO

OBJECTIVES: Testing and treatment for hepatitis B virus (HBV) and hepatitis C virus (HCV) infection are highly effective, high-impact interventions. This article aims to estimate the cost-effectiveness of scaling up these interventions by scenarios, regions, and income groups. METHODS: We modeled costs and impacts of hepatitis elimination in 67 low- and middle-income countries from 2016 to 2030. Costs included testing and treatment commodities, healthcare consultations, and future savings from cirrhosis and hepatocellular carcinomas averted. We modeled disease progression to estimate disability-adjusted life-years (DALYs) averted. We estimated incremental cost-effectiveness ratios (ICERs) by regions and World Bank income groups, according to 3 scenarios: flatline (status quo), progress (testing/treatment according to World Health Organization guidelines), and ambitious (elimination). RESULTS: Compared with no action, current levels of testing and treatment had an ICER of $807/DALY for HBV and -$62/DALY (cost-saving) for HCV. Scaling up to progress scenario, both interventions had ICERs less than the average gross domestic product/capita of countries (HBV: $532/DALY; HCV: $613/DALY). Scaling up from flatline to elimination led to higher ICERs across countries (HBV: $927/DALY; HCV: $2528/DALY, respectively) that remained lower than the average gross domestic product/capita. Sensitivity analysis indicated discount rates and commodity costs were main factors driving results. CONCLUSIONS: Scaling up testing and treatment for HBV and HCV infection as per World Health Organization guidelines is a cost-effective intervention. Elimination leads to a much larger impact though ICERs are higher. Price reduction strategies are needed to achieve elimination given the substantial budget impact at current commodity prices.


Assuntos
Hepatite B/economia , Hepatite C/economia , Antivirais/economia , Antivirais/uso terapêutico , Redução de Custos/economia , Redução de Custos/estatística & dados numéricos , Análise Custo-Benefício , Países em Desenvolvimento/economia , Países em Desenvolvimento/estatística & dados numéricos , Erradicação de Doenças/economia , Erradicação de Doenças/métodos , Hepatite B/diagnóstico , Hepatite B/tratamento farmacológico , Hepatite B/prevenção & controle , Hepatite C/diagnóstico , Hepatite C/tratamento farmacológico , Hepatite C/prevenção & controle , Humanos , Renda/estatística & dados numéricos , Anos de Vida Ajustados por Qualidade de Vida
6.
Curr Opin HIV AIDS ; 15(3): 208-212, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32209813

RESUMO

PURPOSE OF REVIEW: The cure for hepatitis C virus infection has raised hope for a potential hepatitis B virus (HBV) cure, but the high price tag has led to serious questions about the affordability, and thus to access for all. This review discusses cost-effectiveness models, affordability, and access to a potential new cure for chronic HBV infection. RECENT FINDINGS: A cure does not yet exist for HBV, but the antiviral treatments that are currently available help slow down the progression of disease. There is limited research in the area of cost-effectiveness and economic analysis comparing a potential cure. Our preliminary findings from modeling and economic threshold analysis show that cure could be potentially cost-effective or cost-saving. Governments can possibly use the results of economic models for price negotiations. SUMMARY: The highest burden of the HBV infection is in low and middle-income countries. Given that the cost of current treatment has dropped dramatically in recent years as the first line treatments have come off patent, the price for a HBV cure needs to be reasonable and affordable to all people.


Assuntos
Infecções por HIV , Hepatite B Crônica , Hepatite B , Antivirais/uso terapêutico , Infecções por HIV/tratamento farmacológico , Hepatite B/tratamento farmacológico , Vírus da Hepatite B , Humanos
8.
Lancet Glob Health ; 7(9): e1180-e1188, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31353061

RESUMO

BACKGROUND: The World Health Assembly calls for elimination of viral hepatitis as a public health threat by 2030 (ie, -90% incidence and -65% mortality). However, WHO's 2017 cost projections to achieve health-related Sustainable Development Goals did not include the resources needed for hepatitis testing and treatment. We aimed to estimate the incremental commodity cost of adding scaled up interventions for testing and treatment of hepatitis to WHO's investment scenarios. METHODS: We added modelled costs for implementing WHO recommended hepatitis testing and treatment to the 2017 WHO cost projections. We quantified additional requirements for diagnostic tests, medicines, health workers' time, and programme support across 67 low-income and middle-income countries, from 2016-30. A progress scenario scaled up interventions and a more ambitious scenario was modelled to reach elimination by 2030. We used 2018 best available prices of diagnostics and generic medicines. We estimated total costs and the additional investment needed over the projection of the 2016 baseline cost. FINDINGS: The 67 countries considered included 230 million people living with hepatitis B virus (HBV) and 52 million people living with hepatitis C virus (HCV; 90% and 73% of the world's total, respectively). Under the progress scenario, 3250 million people (2400 million for HBV and 850 million for HCV) would be tested and 58·2 million people (24·1 million for HBV and 34·1 million for HCV) would be treated (total additional cost US$ 27·1 billion). Under the ambitious scenario, 11 631 million people (5502 million for HBV and 6129 million for HCV) would be tested and 93·8 million people (32·2 million for HBV and 61·6 million for HCV) would be treated (total additional cost $58·7 billion), averting 4·5 million premature deaths and leading to a gain of 51·5 million healthy life-years by 2030. However, if affordable HCV medicines remained inaccessible in 13 countries where medicine patents are protected, the additional cost of the ambitious scenario would increase to $118 billion. Hepatitis elimination would account for a 1·5% increase to the WHO ambitious health-care strengthening scenario costs, avert an additional 4·6% premature deaths, and add an additional 9·6% healthy life-years from 2016-30. INTERPRETATION: Access to affordable medicines in all countries will be key to reach hepatitis elimination. This study suggests that elimination is feasible in the context of universal health coverage. It points to commodities as key determinants for the overall price tag and to options for cost reduction strategies. FUNDING: WHO, United States Centers for Disease Control and Prevention, Unitaid.


Assuntos
Erradicação de Doenças , Saúde Global , Recursos em Saúde , Hepatite C/prevenção & controle , Avaliação das Necessidades , Cobertura Universal do Seguro de Saúde , Antivirais/economia , Antivirais/uso terapêutico , Países em Desenvolvimento , Previsões , Custos de Cuidados de Saúde/tendências , Hepatite C/epidemiologia , Humanos , Programas de Rastreamento/economia , Desenvolvimento Sustentável , Organização Mundial da Saúde
9.
Health Aff (Millwood) ; 37(7): 1033-1040, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29985701

RESUMO

The National Academies of Sciences, Engineering, and Medicine have concluded that eliminating the public health problem of chronic hepatitis B is feasible. We examined the economic and public health impact of reaching the World Health Organization targets of having 90 percent of chronic hepatitis B cases diagnosed and 80 percent being treated by 2030 in the United States with an annual incremental increase in screening and treatment rates. To reach the targets by 2030 would require screening approximately 14.5 million adults in at-risk populations to diagnose an estimated 870,000 undiagnosed cases and would result in substantial health gains: an increase of 16.5 million quality-adjusted life-years (QALYs), and reductions in liver-related deaths of 37 percent and in cases of compensated cirrhosis of 24 percent, decompensated liver cirrhosis of 51 percent, and liver cancer of 35 percent. Achieving the targets by 2030 would be highly cost-effective at $103 per QALY and would be cost-saving if the antiviral drug price were no more than $114 per month. Achieving them by 2025 would be cost-saving and would reduce liver-related deaths by 47 percent.


Assuntos
Análise Custo-Benefício , Vacinas contra Hepatite B/uso terapêutico , Hepatite B Crônica , Vacinação em Massa , Saúde da População , Anos de Vida Ajustados por Qualidade de Vida , Vacinas contra Hepatite B/economia , Vírus da Hepatite B/isolamento & purificação , Hepatite B Crônica/diagnóstico , Hepatite B Crônica/tratamento farmacológico , Humanos , Programas de Imunização/economia , Programas de Rastreamento , Vacinação em Massa/economia , Vacinação em Massa/métodos , Estados Unidos
10.
PLoS One ; 10(11): e0139876, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26536626

RESUMO

Chronic liver disease and liver cancer associated with chronic hepatitis B (CHB) are leading causes of death among adults in China. Although newborn hepatitis B immunization has successfully reduced the prevalence of CHB in children, about 100 million Chinese adults remain chronically infected. If left unmanaged, 15-25% will die from liver cancer or liver cirrhosis. Antiviral treatment is not necessary for all patients with CHB, but when it is indicated, good response to treatment would prevent disease progression and reduce disease mortality and morbidity, and costly complications. The aim of this study is to analyze the cost-effectiveness of generic and brand antiviral drugs for CHB treatment in China, and assessing various thresholds at which a highly potent, low resistance antiviral drug would be cost-saving and/or cost-effective to introduce in a national treatment program. We developed a Markov simulation model of disease progression using effectiveness and cost data from the medical literature. We measured life-time costs, quality adjusted life years (QALYs), incremental cost-effectiveness ratios (ICERs), and clinical outcomes. The no treatment strategy incurred the highest health care costs ($12,932-$25,293) per patient, and the worst health outcomes, compared to the antiviral treatment strategies. Monotherapy with either entecavir or tenofovir yielded the most QALYs (14.10-19.02) for both HBeAg-positive and negative patients, with or without cirrhosis. Threshold analysis showed entercavir or tenofovir treatment would be cost saving if the drug price is $32-75 (195-460 RMB) per month, highly cost-effective at $62-110 (379-670 RMB) per month and cost-effective at $63-120 (384-734 RMB) per month. This study can support policy decisions regarding the implementation of a national health program for chronic hepatitis B treatment in China at the population level.


Assuntos
Análise Custo-Benefício , Hepatite B Crônica/economia , Programas Nacionais de Saúde , Antivirais/uso terapêutico , China , Medicamentos Genéricos/uso terapêutico , Guanina/análogos & derivados , Guanina/uso terapêutico , Antígenos E da Hepatite B/sangue , Hepatite B Crônica/tratamento farmacológico , Humanos , Cadeias de Markov , Anos de Vida Ajustados por Qualidade de Vida , Tenofovir/uso terapêutico
11.
Biotechnol Adv ; 33(1): 178-190, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25450190

RESUMO

The control of hepatitis B virus (HBV) infection is a challenging task, specifically in developing countries there is limited access to diagnostics and antiviral treatment mainly due to high costs and insufficient healthcare infrastructure. Although the current diagnostic technologies can reliably detect HBV, they are relatively laborious, impractical and require expensive resources that are not suitable for resource-limited settings. Advances in micro/nanotechnology are pioneering the development of new generation methodologies in diagnosis and screening of HBV. Owing to combination of nanomaterials (metal/inorganic nanoparticles, carbon nanotubes, etc.) with microfabrication technologies, utilization of miniaturized sensors detecting HBV and other viruses from ultra-low volume of blood, serum and plasma is realized. The state-of-the-art microfluidic devices with integrated nanotechnologies potentially allow for inexpensive HBV screening at low cost. This review aims to highlight recent advances in nanotechnology and microfabrication processes that are employed for developing point-of-care (POC) HBV assays.


Assuntos
Hepatite B/terapia , Microtecnologia/métodos , Nanotecnologia/métodos , Materiais Biocompatíveis/química , Países em Desenvolvimento/economia , Hepatite B/diagnóstico , Hepatite B/economia , Vírus da Hepatite B/crescimento & desenvolvimento , Vírus da Hepatite B/isolamento & purificação , Humanos , Dispositivos Lab-On-A-Chip , Nanotecnologia/economia , Prevalência , Saúde Pública/economia
12.
Hepatology ; 60(1): 46-55, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24990105

RESUMO

UNLABELLED: Inactive chronic hepatitis B (CHB) carriers make up the largest group of hepatitis B virus-infected patients, and China bears the largest total CHB burden of any country. We therefore assessed the population health impact and cost-effectiveness of a strategy of lifelong monitoring for inactive CHB and treatment of eligible patients in Shanghai, China. We used a computer simulation model to project health outcomes among a population cohort of CHB based on age-specific prevalence of hepatitis B surface antigen (HBsAg), hepatitis B e antigen (HBeAg), and cirrhosis. Using a Markov model we simulated patients' progression through a discrete series of health states, and compared current practice to a monitor and treat (M&T) strategy. We measured lifetime costs and quality-adjusted life years (QALYs) (both discounted at 3% per year), incremental cost-effectiveness ratios (ICERs), and clinical outcomes such as development of hepatocellular carcinoma (HCC). We estimated that there are 1.5 million CHB-infected persons in Shanghai. The M&T strategy costs US$20,730 per patient and yields a discounted QALY of 15.45, which represents incremental costs and health benefits of US$275 and 0.10 QALYs compared to current practice, and an ICER of US$2,996 per QALY gained. In the base case, we estimated that the M&T strategy will reduce HCC and CHB-related mortality by only around 1%. If variables such as adherence to monitoring and treatment could be substantially improved the M&T strategy could reduce HCC by 70% and CHB-related mortality by 83%. CONCLUSION: Lifelong monitoring of inactive CHB carriers is cost-effective in Shanghai according to typical benchmarks for value for money, but achieving substantial population-level health gains depends on identifying more CHB-infected cases in the population, and increasing rates of treatment, monitoring, and treatment adherence.


Assuntos
Antivirais/uso terapêutico , Carcinoma Hepatocelular , Hepatite B Crônica , Neoplasias Hepáticas , Monitorização Imunológica/economia , Inativação de Vírus , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Hepatocelular/economia , Carcinoma Hepatocelular/mortalidade , Carcinoma Hepatocelular/virologia , Criança , Pré-Escolar , China/epidemiologia , Análise Custo-Benefício , Custos de Cuidados de Saúde , Hepatite B Crônica/tratamento farmacológico , Hepatite B Crônica/economia , Hepatite B Crônica/mortalidade , Humanos , Lactente , Recém-Nascido , Neoplasias Hepáticas/economia , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/virologia , Cadeias de Markov , Pessoa de Meia-Idade , Prevalência , Anos de Vida Ajustados por Qualidade de Vida , Adulto Jovem
13.
Best Pract Res Clin Gastroenterol ; 27(6): 973-85, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24182615

RESUMO

With the availability of effective antiviral therapies for chronic viral hepatitis B and C, cost-effectiveness studies have been performed to assess the outcomes and costs of these therapies to support health policy. It is now accepted that treatment of active CHB is cost-effective versus no treatment, although there are a variety of options. And with the new developments around CHC treatment and diagnostic tools it is of interest to both the clinician and policy makers to know both the costs and effects of these choices. The purpose of this article is to provide the reader with an insight into the recent treatment developments and cost-effectiveness issues related to chronic hepatitis B and C treatment, and an overview of recent cost-effectiveness studies evolving around HBV and HCV therapy.


Assuntos
Antivirais/economia , Hepatite B Crônica/tratamento farmacológico , Hepatite B Crônica/economia , Hepatite C Crônica/tratamento farmacológico , Hepatite C Crônica/economia , Antivirais/uso terapêutico , Análise Custo-Benefício , Economia Médica , Custos de Cuidados de Saúde , Humanos , Anos de Vida Ajustados por Qualidade de Vida
14.
Med Decis Making ; 33(6): 767-79, 2013 08.
Artigo em Inglês | MEDLINE | ID: mdl-23715464

RESUMO

Markov models are a simple and powerful tool for analyzing the health and economic effects of health care interventions. These models are usually evaluated in discrete time using cohort analysis. The use of discrete time assumes that changes in health states occur only at the end of a cycle period. Discrete-time Markov models only approximate the process of disease progression, as clinical events typically occur in continuous time. The approximation can yield biased cost-effectiveness estimates for Markov models with long cycle periods and if no half-cycle correction is made. The purpose of this article is to present an overview of methods for evaluating Markov models in continuous time. These methods use mathematical results from stochastic process theory and control theory. The methods are illustrated using an applied example on the cost-effectiveness of antiviral therapy for chronic hepatitis B. The main result is a mathematical solution for the expected time spent in each state in a continuous-time Markov model. It is shown how this solution can account for age-dependent transition rates and discounting of costs and health effects, and how the concept of tunnel states can be used to account for transition rates that depend on the time spent in a state. The applied example shows that the continuous-time model yields more accurate results than the discrete-time model but does not require much computation time and is easily implemented. In conclusion, continuous-time Markov models are a feasible alternative to cohort analysis and can offer several theoretical and practical advantages.


Assuntos
Cadeias de Markov , Modelos Teóricos
15.
Pediatrics ; 131(4): e1135-43, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23530168

RESUMO

OBJECTIVE: To compare the cost-effectiveness of hepatitis B virus (HBV) control strategies combining universal vaccination with hepatitis B immunoglobulin (HBIG) treatment for neonates of carrier mothers. METHODS: Drawing on Taiwan's experience, we developed a decision-analytic model to estimate the clinical and economic outcomes for 4 strategies: (1) strategy V-universal vaccination; (2) strategy S-V plus screening for hepatitis B surface antigen (HBsAg) and HBIG treatment for HBsAg-positive mothers' neonates; (3) strategy E-V plus screening for hepatitis B e-antigen (HBeAg), HBIG for HBeAg-positive mothers' neonates; (4) strategy S&E-V plus screening for HBsAg then HBeAg, HBIG for all HBeAg-positive, and some HBeAg-negative/HBsAg-positive mothers' neonates. RESULTS: Strategy S averted the most infections, followed by S&E, E, and V. In most cases, the more effective strategies were also more costly. The willingness-to-pay (WTP) above which strategy S was cost-effective rose as carrier rate declined and was <$4000 per infection averted for carrier rates >5%. The WTP below which strategy V was optimal also increased as carrier rate declined, from $1400 at 30% carrier rate to $3100 at 5% carrier rate. Strategies involving E were optimal for an intermediate range of WTP that narrowed as carrier rate declined. CONCLUSIONS: HBIG treatment for neonates of HBsAg carrier mothers is likely to be a cost-effective addition to universal vaccination, particularly in settings with adequate health care infrastructure. Targeting HBIG to neonates of higher risk HBeAg-positive mothers may be preferred where WTP is moderate. However, in very resource-limited settings, universal vaccination alone is optimal.


Assuntos
Vacinas contra Hepatite B/economia , Hepatite B/prevenção & controle , Imunoglobulinas/economia , Fatores Imunológicos/economia , Transmissão Vertical de Doenças Infecciosas/prevenção & controle , Vacinação em Massa/economia , Complicações Infecciosas na Gravidez/diagnóstico , Biomarcadores/sangue , Portador Sadio/sangue , Portador Sadio/diagnóstico , Análise Custo-Benefício , Técnicas de Apoio para a Decisão , Árvores de Decisões , Países em Desenvolvimento , Feminino , Hepatite B/diagnóstico , Hepatite B/economia , Hepatite B/transmissão , Antígenos de Superfície da Hepatite B/sangue , Vacinas contra Hepatite B/administração & dosagem , Antígenos E da Hepatite B/sangue , Humanos , Imunoglobulinas/administração & dosagem , Fatores Imunológicos/administração & dosagem , Recém-Nascido , Transmissão Vertical de Doenças Infecciosas/economia , Programas de Rastreamento/economia , Programas de Rastreamento/métodos , Vacinação em Massa/métodos , Modelos Econômicos , Gravidez , Complicações Infecciosas na Gravidez/sangue , Taiwan
16.
Eur J Health Econ ; 13(5): 663-76, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22815098

RESUMO

BACKGROUND/AIMS: Chronic hepatitis B (CHB) infection is a serious public health problem due to its potential liver disease sequelae and highly expensive medical costs such as the need for liver transplantation. The aim of this study was to quantify the burden of active CHB in terms of mortality and morbidity, the eligibility of antiviral treatment and to assess various treatment scenarios and possible salvage combinations for cost-effectiveness. METHODS: A population cohort from a large data base of chronic hepatitis B patients was constructed and stratified according to 10-year age groups, the prevalence of HBsAg, HBV DNA level, ALT level, HBeAg status and the presence of cirrhosis. An age-specific Markov model for disease progression and cost-effectiveness analysis was constructed and calibrated for the specific population setting. RESULTS: Of about 3.2 million estimated HBsAg carriers, 25% are eligible for treatment. If the active cohort remains untreated, 31% will die due to liver related complications. Within a 20-year period, 11% will have developed decompensated cirrhosis, 12% liver cancer and 6% will need liver transplantation. Quality adjusted life years (QALYs) for the no treatment scenario ranged from 9.3 to 14.0. For scenarios with antiviral treatment, QALYs ranged from 9.9 to 14.5 for lamivudine, 13.0-17.5 for salvage therapy, and 16.6-19.0 for the third generation drugs entecavir and tenofovir. CONCLUSION: In a country with considerable amount of active CHB patients, monotherapy with a highly potent third generation drug has the most health-gain, and is cost-effective in both HBeAg-positive and negative in all stages of liver disease.


Assuntos
Antivirais/economia , Hepatite B Crônica/economia , Renda/estatística & dados numéricos , Adolescente , Adulto , Idoso , Antivirais/uso terapêutico , Criança , Pré-Escolar , Estudos de Coortes , Análise Custo-Benefício , Progressão da Doença , Feminino , Hepatite B Crônica/tratamento farmacológico , Hepatite B Crônica/epidemiologia , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Prevalência , Anos de Vida Ajustados por Qualidade de Vida , Sensibilidade e Especificidade , Turquia/epidemiologia , Adulto Jovem
17.
Gastroenterology ; 138(2): 522-30, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19879275

RESUMO

BACKGROUND & AIMS: Persons with chronic hepatitis B virus (HBV) infection are at risk of developing cirrhosis and hepatocellular carcinoma. Early detection of chronic HBV infection through screening and treatment of eligible patients has the potential to prevent these sequelae. We assessed the cost-effectiveness in The Netherlands of systematically screening migrants from countries that have high and intermediate HBV infection levels. METHODS: Epidemiologic data of the expected numbers of patients with active chronic HBV infection in the target population and information about the costs of a screening program were used in a Markov model and used to determine costs and quality-adjusted life years (QALY) for patients who were and were not treated. RESULTS: Compared with the status quo, a 1-time screen for HBV infection can reduce mortality of liver-related diseases by 10%. Using base case estimates, the incremental cost-effectiveness ratio (ICER) of screening, compared with not screening, is euros (euro) 8966 per QALY gained. The ICER ranged from euro7936 to euro11,705 based on univariate sensitivity analysis, varying parameter values of HBV prevalence, participation rate, success in referral, and treatment compliance. Using multivariate sensitivity analysis for treatment effectiveness, the ICER ranged from euro7222 to euro15,694; for disease progression, it ranged from euro5568 to euro60,418. CONCLUSIONS: Early detection and treatment of people with HBV infection can have a large impact on liver-related health outcomes. Systematic screening for chronic HBV infection among migrants is likely to be cost-effective, even using low estimates for HBV prevalence, participation, referral, and treatment compliance.


Assuntos
Antivirais/uso terapêutico , Hepatite B Crônica/diagnóstico , Hepatite B Crônica/tratamento farmacológico , Programas de Rastreamento/economia , Migrantes , Adolescente , Adulto , Idoso , Estudos de Coortes , Análise Custo-Benefício , Feminino , Hepatite B Crônica/epidemiologia , Humanos , Masculino , Cadeias de Markov , Pessoa de Meia-Idade , Análise Multivariada , Países Baixos/epidemiologia , Prevalência , Anos de Vida Ajustados por Qualidade de Vida , Adulto Jovem
18.
Hepatology ; 50(3): 743-51, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19585616

RESUMO

UNLABELLED: The potential impact of long-term antiviral therapy on the burden of chronic hepatitis B has hardly been documented. The aim of this study was to estimate the effects of prolonged antiviral therapy and antiviral resistance on the mortality and morbidity of active chronic hepatitis B patients. A population cohort of chronic hepatitis B patients in the Netherlands was constructed and stratified according to 10-year age groups, prevalence of hepatitis B surface antigen, hepatitis B virus DNA level, alanine aminotransferase level, hepatitis B e antigen status, and presence of cirrhosis. A Markov model was created to mathematically simulate the cohort's progression through a finite series of health states. The analysis was performed on the basis of four scenarios: natural history, long-term therapy with a high-resistance profile drug without or with salvage, and therapy with a low-resistance profile drug. It has been estimated that there were 64,000 people (0.4%) suffering from chronic hepatitis B infection in the Netherlands in 2005, with 6521 (10%) of them having high viremia and elevated alanine aminotransferase levels. Within a 20-year period, 1725 (26%) of the 6521 patients in the active chronic hepatitis B cohort will die because of liver-related causes. Of the 5685 without cirrhosis at entry, 1671 (29%) will develop cirrhosis. Of those 836 with cirrhosis at entry, 619 (74%) will die within a 20-year period. If this active chronic hepatitis B cohort is fully detected and treated, mortality related to liver disease can be reduced by 80% if a low-resistance profile drug is chosen from the start. The effect is due to both the reduction in complications of cirrhosis and the prevention of the development of cirrhosis. CONCLUSION: Long-term antiviral therapy with a strategy that minimizes or controls resistance will have a major preventive effect on liver-related mortality and morbidity.


Assuntos
Antivirais/uso terapêutico , Hepatite B Crônica/tratamento farmacológico , Nucleosídeos/uso terapêutico , Adolescente , Adulto , Idoso , Estudos de Coortes , Farmacorresistência Viral/efeitos dos fármacos , Antígenos E da Hepatite B/análise , Hepatite B Crônica/epidemiologia , Hepatite B Crônica/mortalidade , Humanos , Cirrose Hepática/epidemiologia , Hepatopatias , Cadeias de Markov , Pessoa de Meia-Idade , Sensibilidade e Especificidade
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