Cost-effectiveness of testing for hypercoagulability and effects on treatment strategies in patients with deep vein thrombosis

A Comparison of the Content and Consistency of Methodological Quality and Transferability Checklists for Reviewing Model-Based Economic Evaluations

OBJECTIVES

The aim of this study was to examine whether and how the content of six checklists (Caro, Consensus on Health Economic Criteria [CHEC]-Extended, European Network of Health Economic Databases [EURONHEED], National Institute for Health and Care Excellence [NICE], Philips, Welte) affect the consistency in findings on methodological quality and transferability, using 10 model-based economic evaluations of genetic-guided pharmacotherapy for venous thromboembolism.

METHODS

Each checklist was categorised by domain (structure, data, consistency, etc.) and type of assessment (presence vs. appropriateness) and was applied to each study by two independent reviewers who agreed on ratings via consensus, and discussion with a third reviewer when necessary. Methodological quality scores and rankings were examined using Spearman correlation tests, with subgroup analyses for domains and types of assessment. We compared overall ratings of transferability qualitatively, including how content may affect what is considered 'transferable'.

RESULTS

The checklists had similar proportions of items judging presence and appropriateness, but varying proportions of items across domains. For methodological quality, ranking consistencies were the highest between CHEC-Extended-Philips, Philips-NICE and NICE-Caro, with similar consistencies for domains and type of assessment. For transferability, NICE and Caro identified the same study, which scored high on EURONHEED, as transferable to the UK, while Welte, which considered methodological quality, identified none as transferable.

CONCLUSIONS

We found that the choice of checklist can affect findings on study quality and decisions about whether study results are transferable, indicating that different checklists may shortlist different sets of studies in formulating policy recommendations, leading to different policy decisions. Our systematic approach for evaluating the content of methodological quality and transferability checklists of economic evaluations can be extended to other checklists.

Genetic-guided pharmacotherapy for venous thromboembolism: a systematic and critical review of economic evaluations

Despite the known contributions of genes, genetic-guided pharmacotherapy has not been routinely implemented for venous thromboembolism (VTE). To examine evidence on cost-effectiveness of genetic-guided pharmacotherapy for VTE, we searched six databases, websites of four HTA agencies and citations, with independent double-reviewers in screening, data extraction, and quality rating. The ten eligible studies, all model-based, examined heterogeneous interventions and comparators. Findings varied widely; testing was cost-saving in two base-cases, cost-effective in four, not cost-effective in three, dominated in one. Of 22 model variables that changed decisions about cost-effectiveness, effectiveness/relative effectiveness of the intervention was the most frequent, albeit of poor quality. Studies consistently lacked details on the provision of interventions and comparators as well as on model development and validation. Besides improving the reporting of interventions, comparators, and methodological details, future economic evaluations should examine strategies recommended in guidelines and testing key model variables for decision uncertainty, to advise clinical implementations.

Clinical Phenotype of a First Unprovoked Acute Pulmonary Embolism Associated with Antiphospholipid Antibody Syndrome

BACKGROUND

Antiphospholipid antibody syndrome (APS), an important cause of acquired thrombophilia, is diagnosed when vascular thrombosis or pregnancy morbidity occurs with persistently positive antiphospholipid antibodies (aPL). APS is a risk factor for unprovoked recurrence of pulmonary embolism (PE). Performing laboratory testing for aPL after a first unprovoked acute PE is controversial. We investigated if a specific phenotype existed in patients with unprovoked with acute PE, suggesting the need to evaluate them for APS.

METHODS

We retrospectively reviewed patients with PE and APS (n=24) and those with unprovoked PE with aPL negative (n=44), evaluated 2006-2016 at the Asan Medical Center. We compared patient demographics, clinical manifestations, laboratory findings, and radiological findings between the groups.

RESULTS

On multivariate logistic regression analysis, two models of independent risk factors for APS-PE were suggested. Model I included hemoptysis (odds ratio [OR], 12.897; 95% confidence interval [CI], 1.025-162.343), low PE severity index (OR, 0.948; 95% CI, 0.917-0.979), and activated partial thromboplastin time (aPTT; OR, 1.166; 95% CI, 1.040-1.307). Model II included age (OR, 0.930; 95% CI, 0.893-0.969) and aPTT (OR, 1.104; 95% CI, 1.000-1.217).

CONCLUSION

We conclude that patients with first unprovoked PE with hemoptysis and are age <40; have a low pulmonary embolism severity index, especially in risk class I-II; and/or prolonged aPTT (above 75th percentile of the reference interval), should be suspected of having APS, and undergo laboratory testing for aPL.

Economic evaluation of using a genetic test to direct breast cancer chemoprevention in white women with a previous breast biopsy

BACKGROUND

Tamoxifen therapy reduces the risk of breast cancer but increases the risk of serious adverse events including endometrial cancer and thromboembolic events.

OBJECTIVES

The cost effectiveness of using a commercially available breast cancer risk assessment test (BREVAGen™) to inform the decision of which women should undergo chemoprevention by tamoxifen was modeled in a simulated population of women who had undergone biopsies but had no diagnosis of cancer.

METHODS

A continuous time, discrete event, mathematical model was used to simulate a population of white women aged 40-69 years, who were at elevated risk for breast cancer because of a history of benign breast biopsy. Women were assessed for clinical risk of breast cancer using the Gail model and for genetic risk using a panel of seven common single nucleotide polymorphisms. We evaluated the cost effectiveness of using genetic risk together with clinical risk, instead of clinical risk alone, to determine eligibility for 5 years of tamoxifen therapy. In addition to breast cancer, the simulation included health states of endometrial cancer, pulmonary embolism, deep-vein thrombosis, stroke, and cataract. Estimates of costs in 2012 US dollars were based on Medicare reimbursement rates reported in the literature and utilities for modeled health states were calculated as an average of utilities reported in the literature. A 50-year time horizon was used to observe lifetime effects including survival benefits.

RESULTS

For those women at intermediate risk of developing breast cancer (1.2-1.66 % 5-year risk), the incremental cost-effectiveness ratio for the combined genetic and clinical risk assessment strategy over the clinical risk assessment-only strategy was US$47,000, US$44,000, and US$65,000 per quality-adjusted life-year gained, for women aged 40-49, 50-59, and 60-69 years, respectively (assuming a price of US$945 for genetic testing). Results were sensitive to assumptions about patient adherence, utility of life while taking tamoxifen, and cost of genetic testing.

CONCLUSIONS

From the US payer's perspective, the combined genetic and clinical risk assessment strategy may be a moderately cost-effective alternative to using clinical risk alone to guide chemoprevention recommendations for women at intermediate risk of developing breast cancer.

Prevalência de marcadores de trombofilia em pacientes portadores da síndrome de May-Thurner e trombose de veia ilíaca comum esquerda

CONTEXTO: A relação entre trombose venosa profunda e trombofilia tem sido pouco estudada em indivíduos portadores de compressão da veia ilíaca comum esquerda, conhecida clinicamente como síndrome de May-Thurner. OBJETIVO: Avaliar a prevalência de marcadores de trombofilia nos pacientes portadores de síndrome de May-Thurner e trombose de veia ilíaca comum esquerda. MÉTODOS: Entre março de 1999 e dezembro de 2008, 20 pacientes com síndrome de May-Thurner e trombose de veia ilíaca comum esquerda foram avaliados retrospectivamente quanto à presença de marcadores de trombofilia. RESULTADOS: Foi detectada a associação entre síndrome de May-Thurner e marcadores de trombofilia em 8 pacientes (40%). CONCLUSÃO: A presença de marcadores de trombofilia em pacientes com trombose de veia ilíaca comum esquerda e síndrome de May-Thurner é frequente, porém não difere da prevalência encontrada em pacientes portadores de trombose venosa profunda sem a síndrome associada.

Testing for Inherited Thrombophilias in Arterial Stroke

Background and Purpose— Despite a paucity of evidence supporting a true association of ischemic stroke and the inherited thrombophilias, it is common practice for many neurologists to order these tests as part of the work-up of ischemic stroke, especially in young patients. Treatment with oral anticoagulation is often used in patients with positive results for the inherited thrombophilias.

Methods— We reviewed the literature focusing on case-control studies of the 5 most commonly inherited disorders of coagulation: protein C deficiency, protein S deficiency, antithrombin deficiency, and the factor V Leiden and prothrombin gene mutations in patients with stroke. We also analyzed the available data on stroke patients with inherited thrombophilia and patent foramen ovale.

Results— Multiple case-control studies have not convincingly shown an association of the inherited thrombophilias with ischemic stroke, even in young patients and patients with patent foramen ovale.

Conclusion— If there is an association between the inherited thrombophilias and arterial stroke, then it is a weak one, likely enhanced by other prothrombotic risk factors. The consequences of ordering these tests and attributing causality to an arterial event can result in significant costs to the health care system and pose a potential risk to patients, because this may lead to inappropriate use of long-term oral anticoagulants, exposing patients to harm without a clearly defined benefit.

Management of the antiphospholipid syndrome

Antiphospholipid syndrome (APS) is characterized by recurrent venous or arterial thromboses, fetal losses and thrombocytopenia in the presence of antiphospholipid antibodies, namely lupus anticoagulant, anticardiolipin antibodies or antibodies directed to various proteins, mainly β2 glycoprotein I, or all three. There is consensus in treating patients with APS and first venous thrombosis with oral anticoagulation to a target international normalized ratio (INR) of 2.0-3.0. A recent systematic review recommended a target INR of >3.0 in those patients with APS and arterial thrombosis. The approach in women with obstetric manifestations of APS is based on the use of aspirin plus heparin. The best treatment for patients with the catastrophic variant of the APS is a combination of anticoagulation, corticosteroids, and plasma exchange or intravenous immunoglobulins.

Cost effectiveness of pharmacogenomics: a critical and systematic review

The use of pharmacogenetic testing in clinical practice is limited thus far. A potential barrier to the widespread implementation of pharmacogenetic testing is the lack of evidence on whether testing provides good value for money. The objective of this review was to provide a systematic and critical review of economic evaluations of pharmacogenetic testing. A literature search using publically available databases was performed for articles published up to October 2009. To be included, studies had to meet the definition of being a pharmacogenomic study (defined as use of information on human genetic variation to target drug therapy) and an economic evaluation (defined as an evaluation of both costs and clinical outcomes). Articles that met these criteria were subsequently reviewed and graded using the Quality of Health Economic Studies (QHES) instrument. Lastly, the evidence for biomarker validity and utility were qualitatively assessed using expert opinion. A total of 34 articles were identified using our defined criteria. The most common disease category was thromboembolic-related diseases (26%), while the most common biomarkers were thiopurine methyltransferase and cytochrome P450 2C9 (18% each). Almost all studies were published after 2004 (91%). Two types of studies were identified: cost-effectiveness studies and cost-utility studies, with roughly half of the overall studies being cost-utility studies (53%) and a majority of these published within the last 3 years. The average quality score was 77 (range 29-99). Of the biomarkers reviewed, it was estimated that most had demonstrated clinical validity, but only two had demonstrated clinical utility. Despite a recent increase in the number of economic evaluations of pharmacogenetic applications, further studies examining the clinical validity and utility of these biomarkers are needed to support cost-effectiveness assessments.

Using thrombophilia testing to determine anticoagulation duration in pediatric thrombosis is not cost-effective

OBJECTIVE

To address the cost-effectiveness of thrombophilia testing and treatment strategies among children with a first episode of thrombosis.

STUDY DESIGN

A 2-year Markov model was developed to evaluate the cost-utility of 3 strategies: (1) no testing, anticoagulate for 3 months, (2) no testing, anticoagulate for 6 months, and (3) testing, anticoagulate 3 or 6 months, based on results. We performed a literature search to estimate clinical probabilities and obtained quality-of-life and cost data from published sources.

RESULTS

Total costs per patient were $7900 for no test, treat for 3 months; $8900 for test, treat based on results; and $12,100 for no test, treat for 6 months. Three months of treatment without testing was the least expensive strategy and also the most effective (1.74 quality-adjusted life-years) by 0.01 to 0.03 quality-adjusted life-years. Cost-utility ratios were sensitive to variation in hospitalization and medication costs, but 3 months, no testing, always remained the preferred choice.

CONCLUSIONS

Universal thrombophilia testing after a first episode of thrombosis is not cost-effective when used solely to determine anticoagulation duration. Therefore, a full panel of thrombophilia studies does not need to be an automatic response at the time of any deep venous thrombosis diagnoses.

Massive Pulmonary Embolism Associated With Factor V Leiden, Prothrombin, and Methylenetetrahydrofolate Reductase Gene Mutations in a Young Patient on Oral Contraceptive Pills: A Case Report

Factor V Leiden (Factor V G1691A), prothrombin gene mutation G20210A, and homozygous C677T mutation in the methylenetetrahydrofolate reductase (MTHFR) gene are known to predispose venous thromboembolism (VTE). We present herein a rare case of a young woman heterozygous for these mutations and taking oral contraceptive pills for less than 2 months, diagnosed to have massive deep venous thrombosis and bilateral pulmonary embolism. The patient was managed for 10 days in the hospital and discharged home on oral anticoagulants. This case suggests that screening for these factors in people with family history of thrombosis and in relatives of patients with these mutations is highly recommended to prevent fatal consequences. In addition, a new guideline for treatment and prophylaxis with anticoagulant for these patients and others who are at risk of developing VTE (American College of Chest Physicians [ACCP] guidelines-Chest 2008) has been published recently. Our recommendation is to promote for the internationally published algorithms through their application, where necessary, to prevent any future thrombotic morbidity or mortality incidents.

Should patients with venous thromboembolism be screened for thrombophilia?

In the mid-19th century, Virchow identified hypercoagulability as part of the triad leading to venous thrombosis, but the specific causes of hypercoagulability remained a mystery for another century. The first specific cause to be identified was antithrombin III deficiency. Many other causes of thrombophilia, both genetic and acquired, have been discovered since then. The 2 most common genetic causes of thrombophilia are the Leiden mutation of factor V and the G20210A mutation of prothrombin. The most common acquired cause is antiphospholipid syndrome. These factors increase the relative risk of an initial episode of venous thromboembolism (VTE) by a factor of 2 to 10, but the actual risk remains relatively modest. Therefore, thrombophilia screening to prevent initial episodes of VTE is not indicated, except possibly in women with a family history of idiopathic VTE who are considering oral contraceptive therapy. Some physicians screen for thrombophilia to aid decision making concerning the duration of anticoagulant therapy. However, several studies have demonstrated that, with the exception of antiphospholipid syndrome, thrombophilia does not significantly increase the risk of recurrent VTE. On the other hand, idiopathic VTE significantly increases the risk of recurrence in patients with or without thrombophilia.

Pancreatic-stent placement for prevention of post-ERCP pancreatitis: a cost-effectiveness analysis

BACKGROUND

Controlled trials support pancreatic-stent placement as an effective intervention for the prevention of post-ERCP acute pancreatitis in high-risk patients.

OBJECTIVE

To perform a decision analysis to evaluate the most cost-effective strategy for preventing post-ERCP pancreatitis.

DESIGN

Cost-effectiveness analysis.

SETTING

Patients undergoing ERCP.

INTERVENTIONS

Three competing strategies were evaluated in a decision analysis model from a third-party-payer perspective in hypothetical patients undergoing ERCP. In strategy I, none of the patients had pancreatic-stent placement. Strategy II had only those patients identified to be at high risk for post-ERCP, and, in strategy III, all patients underwent prophylactic stent placement. Probabilities of developing post-ERCP pancreatitis and the risk reduction by placement of a pancreatic stent were obtained from published information. Cost estimates were obtained from Medicare reimbursement rates.

MAIN OUTCOME MEASUREMENTS

Incremental cost-effectiveness ratio (ICER) of different strategies.

RESULTS

Strategy I was the least-expensive strategy but yielded the least number of life years. Strategy II yielded the highest number of years of life, with an ICER of $11,766 per year of life saved, and strategy III was dominated by strategy II.

LIMITATIONS

Indirect costs and pharmacologic prophylaxis were not considered in this analysis.

CONCLUSIONS

Pancreatic-stent placement for the prevention of post-ERCP pancreatitis in high-risk patients is a cost-effective strategy.

Economic analyses of human genetics services: a systematic review

PURPOSE

The study's purpose was to conduct a structured review of economic analyses of genetic services. These will be increasingly valuable tools for assessing the clinical and economic outcomes of new medical technologies.

METHODS

We searched for economic studies published between January 1990 and August 2004 from a variety of publicly available databases. Articles were first reviewed to determine whether they were original studies, and second to determine whether they were formal cost-effectiveness analyses by established criteria. Articles meeting these criteria were graded using a validated rating scale.

RESULTS

Of 149 articles, 63 met established criteria for cost-effectiveness analyses. The majority (87%) were published since 1996. The majority of studies considered adult (31) or prenatal (25) conditions with the remainder considering preconception or pediatric conditions. More than half used life years gained or an ad hoc measure of outcome (e.g., cases detected). Twenty-five percent measured outcome as quality-adjusted life years. The disease areas most considered were cancer (21%) and aneuploidies (18%). The average quality ranking was 87 of 100 possible (range 48-100). Common shortcomings included lack of statement of perspective, lack of discussion of potential bias, and lack of disclosure of funding sources.

CONCLUSIONS

Relatively few economic evaluations are available for genetic services, and most are clustered in specific disease areas. Overall quality was high, but varied widely. Most shortcomings that would improve study quality are easy to address. To improve the relevance of these studies, researchers need to incorporate measures of outcome that are familiar to decision makers, including quality-adjusted life years.

Genomic medicine and thrombotic risk: Who, when, how and why?

Major advances in Human Genome research could significantly change the clinical medical practice, providing new possibilities for both diagnosing and treating common pathologies. Many genetic tests are now commercially available for predicting future risk of common disorders. However, genetic testing has potential benefits but also limitations for the patients, and it should not be used to 'screen' the general population. Diagnostic assays for a predisposition of both venous and arterial thrombosis are among the most requested genetic tests in molecular diagnostics laboratories. However, there is considerable uncertainty as to how this information should be utilized in patient management. Both the medical community and the patients need to obtain accurate information concerning the appropriate use of genetic testing. The purpose of this article is to discuss the usefulness and the practical applications of thrombotic genetic testing in order to define which patients should be tested for both venous and arterial thrombotic risk as well as to have an acceptable cost/benefit ratio and to prevent patients' anxiety.

Cost-effectiveness of screening for deep vein thrombosis by ultrasound at admission to stroke rehabilitation

OBJECTIVE

This project was a cost-effectiveness analysis of the practice of routine Doppler ultrasound screening for deep vein thrombosis (DVT) in patients with ischemic stroke at the time of admission to rehabilitation.

DESIGN

A decision-analysis model was created to compare 2 approaches for detecting DVT in a stroke population: (1) screening all patients with acute ischemic stroke at admission to stroke rehabilitation for DVT by Doppler ultrasound with subsequent treatment; or (2) clinical surveillance for signs of DVT and treatment after confirmation by Doppler ultrasound. The prevalence of DVT, risk of complication from DVT, and risk of complication from treatment were obtained from published reports. Costs are in 2004 dollars and the effectiveness was measured in quality-adjusted life-years (QALYs) gained. We conducted these analyses from a societal perspective.

SETTING

Inpatient stroke rehabilitation unit.

PARTICIPANTS

Not applicable.

INTERVENTION

Screening all patients with acute ischemic stroke at admission to stroke rehabilitation for DVT by Doppler ultrasound with subsequent treatment.

MAIN OUTCOME MEASURE

Cost in 2004 dollars per QALY gained by screening all patients with acute ischemic stroke at admission to stroke rehabilitation for DVT by Doppler ultrasound with subsequent treatment.

RESULTS

The expected utility of screening patients with ischemic stroke for DVT by Doppler ultrasound on admission to rehabilitation is 1.875 QALYs and that of not screening is 1.872 QALYs. The expected gain is .0026 QALYs (23 h). Obtaining this increase in quality-adjusted life incurs additional cost of 168 dollars per stroke patient and a marginal cost-effectiveness of 67,200 dollars for each QALY gained.

CONCLUSIONS

This study estimates that the cost-effectiveness ratio is considerably higher than that reported in other rehabilitation conditions and higher than the commonly stated level for an intervention to be considered cost-effective. The difference from previous reports primarily relates to the shorter life expectancy following stroke, the prevalence of occult DVT at admission, rate of complications of anticoagulation, and the estimates of the screening's test characteristics used in our study. Further study of these areas is likely to contribute to improving our understanding of the most appropriate care of these patients.

Screening for thrombophilia in high-risk situations: a meta-analysis and cost-effectiveness analysis

Laboratory testing for the identification of heritable thrombophilia in high-risk patient groups have become common practice; however, indiscriminate testing of all patients is unjustified. The objective of this study was to evaluate the cost-effectiveness of universal and selective history-based thrombophilia screening relative to no screening, from the perspective of the UK National Health Service, in women prior to prescribing combined oral contraceptives and hormone replacement therapy, women during pregnancy and patients prior to major orthopaedic surgery. A decision analysis model was developed, and data from meta-analysis, the literature and two Delphi studies were incorporated in the model. Incremental cost-effectiveness ratios (ICERs) for screening compared with no screening was calculated for each patient group. Of all the patient groups evaluated, universal screening of women prior to prescribing hormone replacement therapy was the most cost-effective (ICER 6824 pounds). In contrast, universal screening of women prior to prescribing combined oral contraceptives was the least cost-effective strategy (ICER 202,402 pounds). Selective thrombophilia screening based on previous personal and/or family history of venous thromboembolism was more cost-effective than universal screening in all the patient groups evaluated.

Cost-effectiveness of low-molecular-weight heparin for treatment of pulmonary embolism

BACKGROUND

Low-molecular-weight heparin (LMWH) appears to be safe and effective for treating pulmonary embolism (PE), but its cost-effectiveness has not been assessed.

METHODS

We built a Markov state-transition model to evaluate the medical and economic outcomes of a 6-day course with fixed-dose LMWH or adjusted-dose unfractionated heparin (UFH) in a hypothetical cohort of 60-year-old patients with acute submassive PE. Probabilities for clinical outcomes were obtained from a meta-analysis of clinical trials. Cost estimates were derived from Medicare reimbursement data and other sources. The base-case analysis used an inpatient setting, whereas secondary analyses examined early discharge and outpatient treatment with LMWH. Using a societal perspective, strategies were compared based on lifetime costs, quality-adjusted life-years (QALYs), and the incremental cost-effectiveness ratio.

RESULTS

Inpatient treatment costs were higher for LMWH treatment than for UFH (dollar 13,001 vs dollar 12,780), but LMWH yielded a greater number of QALYs than did UFH (7.677 QALYs vs 7.493 QALYs). The incremental costs of dollar 221 and the corresponding incremental effectiveness of 0.184 QALYs resulted in an incremental cost-effectiveness ratio of dollar 1,209/QALY. Our results were highly robust in sensitivity analyses. LMWH became cost-saving if the daily pharmacy costs for LMWH were < dollar 51, if > or = 8% of patients were eligible for early discharge, or if > or = 5% of patients could be treated entirely as outpatients.

CONCLUSION

For inpatient treatment of PE, the use of LMWH is cost-effective compared to UFH. Early discharge or outpatient treatment in suitable patients with PE would lead to substantial cost savings.

Acute cytomegalovirus infection complicated by venous thrombosis: a case report

BACKGROUND

CMV-induced vasculopathy and thrombosis have been reported, but they are rare conditions usually encountered in immunocompromised patients. However more and more complications of CMV infections are recognized in immunocompetent patients.

CASE PRESENTATION

We present a case report of a previously healthy adult with cytomegalovirus infection that was complicated by tibiopopliteal deep venous thrombosis and in whom Factor V Leiden heterozygous mutation was found.

CONCLUSION

This new case report emphasizes the involvement of cytomegalovirus in induction of vascular thrombosis in patients with predisposing risk factors for thrombosis. It is necessary to screen for CMV infection in patients with spontaneous thrombosis and an history of fever.

Oral anticoagulation strategies after a first idiopathic venous thromboembolic event

PURPOSE

The optimal duration and intensity of warfarin therapy after a first idiopathic venous thromboembolic event are uncertain. We used decision analysis to evaluate clinical and economic outcomes of different anticoagulation strategies with warfarin.

METHODS

We built a Markov model to assess 6 strategies to treat 40- to 80-year-old men and women after their first idiopathic venous thromboembolic event: 3-month, 6-month, 12-month, 24-month, and unlimited-duration conventional-intensity anticoagulation (International Normalized Ratio, 2-3) and unlimited-duration low-intensity anticoagulation (International Normalized Ratio, 1.5-2). The model incorporated age- and sex-specific clinical parameters, utilities, and costs. Using a societal perspective, we compared strategies based on quality-adjusted life-years (QALYs), lifetime costs, and incremental cost-effectiveness ratios.

RESULTS

In our baseline analysis, incremental cost-effectiveness ratios were lower in younger patients and in men, reflecting the higher bleeding risk at older ages, and the lower risk of recurrence among women. Based on a willingness-to-pay of <$50000/QALY, the 24-month strategy was most cost-effective in 40-year-old men ($48805/QALY), while the 6-month strategy was preferred in 40-year-old women ($35977/QALY) and 60-year-old men ($29878/QALY). In patients aged >/=80 years, 3-month anticoagulation was less costly and more effective than other strategies. Cost-effectiveness results were influenced by the risks associated with recurrent venous thromboembolism, the major bleeding risk of conventional-intensity anticoagulation and the disutility of taking warfarin.

CONCLUSION

Longer initial conventional-intensity anticoagulation is cost-effective in younger patients while 3 months of anticoagulation is preferred in elderly patients. Patient age, sex, clinical factors, and patient preferences should be incorporated into medical decision making when selecting an appropriate anticoagulation strategy.

A systematic review of cost-effectiveness analyses of pharmacogenomic interventions

Cost-effectiveness analysis is a widely used tool to assess the value of healthcare interventions. Our objective was to conduct a systematic review of the literature on the cost effectiveness of pharmacogenomic interventions. We found 11 studies that met our inclusion criteria. The most commonly examined disease was deep vein thrombosis (n = 4), followed by cancer (n = 3) and viral infections (n = 3); the most frequently examined mutation was factor V Leiden (n = 5); and the majority of the mutations examined were inherited mutations (n = 7), although several studies looked at acquired (tumor or viral) mutations (n = 4). The majority of the studies reported a favorable cost-effectiveness ratio for the pharmacogenomic-based strategy (n = 7), while two studies reported that the pharmacogenomic-based strategy was not cost effective and two were equivocal. We conclude that there have been few evaluations of the economic costs and benefits of pharmacogenomic interventions and they have covered a limited number of conditions. Further analyses that can be used to guide the use of pharmacogenomics in clinical practice and in developing health policies are urgently needed.