The psychological impact of testing for thrombophilia: a systematic review

Laboratory Evaluation of Thrombophilia

Venous thromboembolism (VTE) occurs typically in the veins of the lower extremities and/or as pulmonary embolism. There is a myriad of causes of VTE ranging from provoked causes (e.g., surgery, cancer) to unprovoked causes (e.g., inherited abnormalities) or multiple factors that combine to initiate the cause. Thrombophilia is a complex, multi-factorial disease that may result in VTE. The mechanism(s) and causes of thrombophilia are complex and not completely understood. In healthcare today, only some answers about the pathophysiology, diagnosis, and prevention of thrombophilia have been elucidated. The laboratory analysis for thrombophilia is not consistently applied, and has changed over time, but remains varied by providers and laboratories as well. Both groups must establish harmonized guidelines for patient selection and appropriate conditions for analysis of inherited and acquired risk factors. This chapter discusses the pathophysiology of thrombophilia, and evidence-based medicine guidelines discuss the optimum laboratory testing algorithms and protocols for selection and analyzing VTE patients to ensure a cost-effective use of limited resources.

Prenatal electrocardiogram testing and postpartum depression: A population-based cohort study

Background

Cardiovascular symptoms in pregnancy may be a clue to psychological distress. We examined whether electrocardiogram testing in pregnant women is associated with an increased risk of subsequent postpartum depression.

Methods

We conducted a population-based cohort study of pregnant women who delivered in Ontario, Canada comparing women who received a prenatal ECG to women who did not.

Results

In total, 3,238,218 women gave birth during the 25-year study period of whom 157,352 (5%) received an electrocardiogram during prenatal care. Receiving an electrocardiogram test was associated with a one-third relative increase in the odds of postpartum depression (odds ratio 1.34; 95% confidence interval 1.29-1.39, p < 0.001).

Conclusion

The association between prenatal electrocardiogram testing and postpartum depression suggests a possible link of organic disease with mental illness, and emphasizes that cardiovascular symptoms may be a clinical clue to the presence of an underlying mood disorder.

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.

Venous Thromboembolism: Genetics and Thrombophilias

Venous thromboembolism (VTE) is a major cause of morbidity and mortality throughout the world. Up to one half of patients who present with VTE will have an underlying thrombophilic defect. This knowledge has led to a widespread practice of testing for such defects in patients who develop VTE. However, identifying a hereditary thrombophilia by itself does not necessarily change outcomes or dictate therapy. Furthermore, family history of VTE by itself can increase an asymptomatic person's VTE risk several-fold, independent of detecting a known inherited thrombophilia. In this article, we will describe the current validated hereditary thrombophilias including their history, prevalence, and association with VTE. With a focus on evaluating both risks and benefits of testing, we will also explore the controversies of why, who, and when to test as well as discuss contemporary societal guidelines. Lastly, we will share how these tests have been integrated into clinical practice and how to best utilize them in the future.

Serological Parameters and Vascular Investigation for a Better Assessment in DVT during Pregnancy-A Systematic Review

Pregnancy and the postpartum period represent a condition characterized by a thrombotic predisposition. The majority of pregnant women do not face acute or severe thrombotic events. In general, mild inconveniences such as leg swelling or moderately painful thrombotic events (phlebitis) are encountered. However, when pregnancy is associated with inherited or acquired deficits that affect homeostasis, the risk of acute or even life-threatening events can increase significantly. The major consequence is the loss of the fetus or the venous thromboembolism that endangers the mother's life. Venous thromboembolism is caused by deep vein thrombosis, therefore timely detection and especially the assessment of the extent of the thrombotic event are crucial. In this paper we have summarized the most important paraclinical investigations. The study emphasizes the importance of selecting the methods of investigation. The right choice allows establishing a correct diagnosis and individualizing the treatment.

Pulmonary embolism: update on management and controversies

Pulmonary embolism is a common and potentially fatal cardiovascular disorder that must be promptly diagnosed and treated. The diagnosis, risk assessment, and management of pulmonary embolism have evolved with a better understanding of efficient use of diagnostic and therapeutic options. The use of either clinical probability adjusted or age adjusted D-dimer interpretation has led to a reduction in diagnostic imaging to exclude pulmonary embolism. Direct oral anticoagulation therapies are safe, effective, and convenient treatments for most patients with acute venous thromboembolism, with a lower risk of bleeding than vitamin K antagonists. These oral therapeutic options have opened up opportunities for safe outpatient management of pulmonary embolism in selected patients. Recent clinical trials exploring the use of systemic thrombolysis in intermediate to high risk pulmonary embolism suggest that this therapy should be reserved for patients with evidence of hemodynamic compromise. The role of low dose systemic or catheter directed thrombolysis in other patient subgroups is uncertain. After a diagnosis of pulmonary embolism, all patients should be assessed for risk of recurrent venous thromboembolism to guide duration of anticoagulation. Patients with a venous thromboembolism associated with a strong, transient, provoking risk factor can safely discontinue anticoagulation after three months of treatment. Patients with an ongoing strong risk factor, such as cancer, or unprovoked events are at increased risk of recurrent events and should be considered for extended treatment. The use of a risk prediction score can help to identify patients with unprovoked venous thromboembolism who can benefit from extended duration therapy. Despite major advances in the management of pulmonary embolism, up to half of patients report chronic functional limitations. Such patients should be screened for chronic thromboembolic pulmonary hypertension, but only a small proportion will have this as the explanation of their symptoms. In the remaining patients, future studies are needed to understand the pathophysiology and explore interventions to improve quality of life.

Heritable thrombophilia test utilization and cost savings following guideline-based restrictions: An interrupted time series analysis

OBJECTIVE

Existing guidelines provide indications for appropriate heritable thrombophilia (HT) testing but testing practices often do not conform to these guidelines. The Canadian province of Newfoundland and Labrador (NL) implemented a new 'hard-stop' guideline-based approach to HT testing whereby tests ordered outside specific guidelines were rejected. The objective of this study was to evaluate the effectiveness of this intervention and the associated cost savings.

METHODS

Using data on number of HT tests ordered and performed in NL between December 1, 2014 and February 28, 2018, we conducted interrupted time series analyses to analyze changes in number of HT tests ordered and performed following the intervention. Cost savings were estimated by comparing cost of tests actually performed after enforcement of guidelines with the cost of counterfactual number of tests that would have been performed without guidelines.

RESULTS

Guideline-based restrictions on HT testing were associated with a 86-98% decline in the number of tests performed (p < 0.05). Contrary to previous softer, educational approaches to restricting HT testing, number of Protein C and Factor V Leiden/Prothrombin G20210A tests ordered also declined post-guideline implementation (p < 0.05). Annual cost savings associated with reductions in tests performed were estimated to be $205,154 for NL from a societal perspective. We estimated that if this model was expanded across Canada, annual cost savings could be as large as $14.2 million from a societal perspective.

CONCLUSIONS

A 'hard-stop' guideline-based approach to restricting HT testing is associated with significant reductions in HT testing and meaningful cost savings.

Thrombosis in children: Which test to whom, when and how much necessary?

Pediatric thrombosis is multifactorial, and usually risk factors either congenital or acquired are present. After 2000, systematic reviews and meta-analysis on pediatric venous thromboembolic disease and inherited thrombophilia revealed elevated thrombotic risks in these children. In this review, we discuss thrombosis and new literature in various pediatric patient groups and the usefulness of thrombophilia testing.

Patient experience and utility of genetic information: a cross-sectional study among patients tested for cancer susceptibility and thrombophilia

We evaluated whether genetic tests with evidence of clinical and personal utility (i.e. APC and BRCA1/2 tests) are associated with higher satisfaction and a more positive perception of care experience than those with undefined utility (i.e. tests for thrombophilia). A cross-sectional survey was performed through telephone interviews to patients tested for deleterious variants in APC or BRCA1/2 genes, or for inherited thrombophilia (FV Leiden and/or FIIG20210A) during a 5-year period (2008-2012). Three aspects of patient experience were assessed: effective communication through pre- and post-test genetic counselling; collaboration between caregivers on the management of patient care; and impact of genetic testing on quality of life. Overall 237 patients had telephone interviews. Multivariate logistic regression analyses showed that patients tested for APC or BRCA1/2 variants were more likely to be satisfied with both pre- and post-test counselling than those tested for inherited thrombophilia (APC vs. thrombophilia, p = 0.039 and 0.005; BRCA1/2 vs. thrombophilia, p = 0.030 and <0.001). Patients tested for APC were more likely to report an improvement in quality of life than those for thrombophilia (OR = 2.97, 95%CI 1.14, 7.72; p = 0.025). A positive association was observed between patients who underwent BRCA1/2 testing, and self-perceived improvement in quality of life (OR = 1.41, 95%CI 0.74, 2.69; p = 0.294). Tests of undefined clinical and personal utility are associated with a lower degree of patient satisfaction with genetic counselling and no clear opinions on changes in quality of life compared with those with well-defined utility.

Parents' attitudes toward genetic testing of children for health conditions: A systematic review

This review assessed parents' attitudes toward childhood genetic testing for health conditions, with a focus on perceived advantages and disadvantages. We also evaluated the factors that influence parents' attitudes toward childhood genetic testing. We searched Medline, Medline In-Process, EMBASE, PsycINFO, Social Work Abstracts and CINAHL. We screened 945 abstracts and identified 21 studies representing the views of 3934 parents. Parents reported largely positive attitudes toward childhood genetic testing across different genetic tests with varying medical utility. Parents perceived a range of advantages and disadvantages of childhood genetic testing. Childhood genetic testing was viewed by most as beneficial. Parents' education level, genetic status, sex and sociodemographic status were associated with reported attitudes. This yielded some conflicting findings, indicating the need for further research. Genetic counseling remains essential to support this population in making well-informed decisions. Targeted interventions tailored to specific families with different sociodemographic characteristics may be useful. Further research on the long-term impact of childhood genetic testing on families is warranted.

Inherited Thrombophilia in Pediatric Venous Thromboembolic Disease: Why and Who to Test

Venous thromboembolic disease in childhood is a multifactorial disease. Risk factors include acquired clinical risk factors such as a central venous catheter and underlying disease and inherited thrombophilia. Inherited thrombophilia is defined as a genetically determined tendency to develop venous thromboembolism. In contrast to adults, acquired clinical risk factors play a larger role than inherited thrombophilia in the development of thrombotic disease in children. The contributing role of inherited thrombophilia is not clear in many pediatric thrombotic events, especially catheter-related thrombosis. Furthermore, identification of inherited thrombophilia will not often influence acute management of the thrombotic event as well as the duration of anticoagulation. In some patients, however, detection of inherited thrombophilia may lead to identification of other family members who can be counseled for their thrombotic risk. This article discusses the potential arguments for testing of inherited thrombophilia, including factor V Leiden mutation, prothrombin mutation, and deficiencies of antithrombin, protein C, or protein S and suggests some patient groups in childhood, which may be tested.

Inherited thrombophilia: a double-edged sword

Inherited thrombophilia is a blood coagulation disorder that increases the risk for venous thromboembolism (VTE). During the last decades, the practice of testing has evolved from testing selected populations, leading to high perceived risks, to broad testing for various conditions that included VTE, arterial thrombosis, and pregnancy complications. Because results of such tests usually do not guide treatment decisions, not testing patients with VTE for inherited thrombophilia is on the "Choosing Wisely" list endorsed by multiple specialty societies, including ASH. Inherited thrombophilia can be regarded a double-edged sword, as despite the rationale not to test, it is still being performed frequently. Another way of seeing inherited thrombophilia as a double-edged sword lies in its 2-sided association with reproduction, both in men and in women. Current areas of research are whether women with inherited thrombophilia and pregnancy complications benefit from anticoagulant therapy with regard to improving the chance of a successful pregnancy. Potential effects of inherited thrombophilia, most notably factor V Leiden, on improved embryo implantation in women and sperm counts in men are intriguing, but are currently poorly understood.

Guidance for the evaluation and treatment of hereditary and acquired thrombophilia

Thrombophilias are hereditary and/or acquired conditions that predispose patients to thrombosis. Testing for thrombophilia is commonly performed in patients with venous thrombosis and their relatives; however such testing usually does not provide information that impacts management and may result in harm. This manuscript, initiated by the Anticoagulation Forum, provides clinical guidance for thrombophilia testing in five clinical situations: following 1) provoked venous thromboembolism, 2) unprovoked venous thromboembolism; 3) in relatives of patients with thrombosis, 4) in female relatives of patients with thrombosis considering estrogen use; and 5) in female relatives of patients with thrombosis who are considering pregnancy. Additionally, guidance is provided regarding the timing of thrombophilia testing. The role of thrombophilia testing in arterial thrombosis and for evaluation of recurrent pregnancy loss is not addressed. Statements are based on existing guidelines and consensus expert opinion where guidelines are lacking. We recommend that thrombophilia testing not be performed in most situations. When performed, it should be used in a highly selective manner, and only in circumstances where the information obtained will influence a decision important to the patient, and outweigh the potential risks of testing. Testing should not be performed during acute thrombosis or during the initial (3-month) period of anticoagulation.

A Qualitative Study to Appraise Patients and Family Members Perceptions, Knowledge, and Attitudes towards Venous Thromboembolism Risk

Objective

This study aimed to examine perception, knowledge and concerns developed by patients and their family as regards venous thromboembolism (VTE) risk.

Methods

We conducted a qualitative study. Participants were: (1) patients with unprovoked VTE with either factor V Leiden mutation or G20210A prothrombin gene mutation or not; and (2) their first-degree relatives. Interviews took place mostly at Brest University Hospital. Participants produced narratives of the patient’s illness, stressing their perception of the disorder, its mechanisms, etiology, circumstances and risk factors. Interviews were audiotaped and transcribed verbatim. On an ongoing basis, central themes were identified and data from narratives were categorized by these themes.

Results

A total of ten patients and 25 first-degree relatives were interviewed. Analyses of patient’s narratives suggested 4 main themes: (1) concerns about initial symptoms and suspicion of VTE. The longer the duration of the initial phase, the more likely anxiety took place and persisted after diagnosis; (2) underestimation of potential life-threatening episode once being managed in emergency; (3) possible biographical disruption with inability to cope with the event; and (4) secondary prevention attitudes motivated by remains of the episode and favoring general prevention attitudes. Analyses of the first-degree relatives narratives suggested 3 main themes: (1) common interpretation of the VTE episode shared within the family; (2) diverse and sometimes confusing interpretation of the genetic status; and, (3) interpretation of clinical signs linked to VTE transmission within the family.

Conclusions

Construction of the risk of VTE is based on patient’s initial experience and shared within the family. Collection of narratives illustrates the gap between these perceptions and current medical knowledge. These results support the need to collect the perceptions of the VTE episode and its consequences, as a prerequisite to any health education process.

[Importance of thrombophilia screening]

Thrombophilia testing denotes a test battery for inherited or acquired features associated with a tendency for clot formation. Currently, it is being used in a frequency and to an extent which is not supported by evidence. In order to protect patients from unnecessary worry and stigmatization, but also for reasons of cost effectiveness, thrombophilia testing should be reduced to a very small number of medically justifiable indications which are outlined in this review.Those indications include the following: secondary prevention of venous thromboembolism in patients from a thrombophilic family, i.e., with two or more first degree relatives with venous thromboembolism (VTE), or patients with suspected antiphospholipid syndrome; women prior to oral contraception or planning to become pregnant if they had no prior VTE but have one or more first-degree relatives with VTE-provided they are willing to follow the consequences of positive test results; women with recurrent miscarriage. The inappropriate indications are discussed as well.The test panel for inherited thrombophilias includes deficiencies of antithrombin, protein C and protein S, factor V Leiden and prothrombin 20210 mutation. Patients with suspicion of antiphospholipid syndrome have to be tested for lupus anticoagulans, anti-cardiolipin antibodies, and anti-β2-glycoprotein I-antibodies. It is important to do the blood sampling at an appropriate point in time.

Preventing thrombophilia-related complications of pregnancy: an update

Approximately half of all pregnancy-related venous thromboembolic events are associated with thrombophilia. Although the most compelling data for a link between thrombophilia and other adverse pregnancy outcomes derive from women with antiphospholipid antibodies, some studies also suggest an association between these pregnancy complications and hereditary thrombophilias. Management of thrombophilia often involves anticoagulant therapy; however, use of these agents during pregnancy is challenging. There is a paucity of high-quality studies and consequently, recommendations are based largely on extrapolation from data in nonpregnant women, in addition to observational studies and a few small randomized studies. This article will review the impact of the thrombophilias on pregnancy and its outcome, evidence for therapies aimed at the prevention of thrombophilia-related pregnancy complications, and the most recent recommendations contained in the 9th Edition of the American College of Chest Physicians Evidence-Based Clinical Practice Guidelines.

The influence of medical testing on patients' health: an overview from the gynecologists' perspective

Background

A medical tests may influence the health of patients by guiding clinical decisions, such as treatment in case of a positive test result. However, a medical test can influence the health of patients through other mechanisms as well, like giving reassurance. To make a clinical recommendation about a medical test, we should be aware of the full range of effects of that test on patients. This requires an understanding of the range of effects that medical testing can have on patients. This study evaluates the mechanisms through which medical testing can influence patients’ health, other than the effect on clinical management, from a gynecologist’s perspective.

Methods

A qualitative study in which explorative focus groups were conducted with gynecologists, gynecological residents and gynecological M.D. researchers (n = 43). Discussions were transcribed verbatim. Transcriptions were coded inductively and analyzed by three researchers.

Results

All participants contributed various clinical examples in which medical testing had influenced patients’ health. Clinical examples illustrated that testing, in itself or in interaction with contextual factors, may provoke a wide range of effects on patients. Our data showed that testing can influence the doctor’s perceptions of the patients’ appraisal of their illness, their perceived control, or the doctor-patient relationship. This may lead to changes in psychological, behavioral, and/or medical outcomes, both favorably or unfavorably. The data were used to construct a conceptual framework of effects of medical testing on patients.

Conclusions

Besides supporting clinical decision making, medical testing may have favorable or unfavorable effects on patients’ health though several mechanisms.

Prevalence of thrombophilia according to age at the first manifestation of venous thromboembolism: results from the MAISTHRO registry

Thrombophilia is a well-established risk factor for a venous thromboembolic event (VTE), and it has been proposed that hereditary thrombophilia may substantially contribute to the development of VTE in young patients. We aimed to analyse the prevalence of thrombophilia with special regard to the age of VTE manifestation. The study cohort consisted of 1490 patients (58% females) with a median age 43 years at the time of their first VTE. At least one thrombophilic disorder was identified in 50·1% of patients. The probability of detecting a hereditary thrombophilia declined significantly with advancing age (from 49·3% in patients aged 20 years and younger to 21·9% in patients over the age of 70 years; P < 0·001). This may be primarily attributed to the decreasing frequencies of the F5 R506Q (factor V Leiden) mutation and deficiencies of protein C or protein S with older age at the time of the initial VTE event. Moreover, thrombophilia was more prevalent in unprovoked compared with risk-associated VTE (57·7% vs. 47·7%; P = 0·001). The decline in the prevalence of hereditary thrombophilia with older ages supports the use of a selected thrombophilia screening strategy dependent on age and the presence or absence of additional VTE risk factors.

To be or not to be: the patient's view of thrombophilia testing

INTRODUCTION

The literature on the psychological effects of thrombophilia testing is unclear. Little is known about the complex world of significance subjects construct around the test.

OBJECTIVE

The study explored the peculiar network of implicit meanings that may be linked to the experience of being tested.

MATERIALS AND METHODS

The research was designed according to Interpretative Phenomenological Analysis (IPA). 19 patients were interviewed. Integral verbatim reports of the interviews were analyzed through an inductive process aimed at gaining a holistic understanding of the narratives.

RESULTS

Two main issues were identified, each with sub-issues: (1) the clinical problem: (1.1) unhealthy blood and (1.2) the family issue; (2) the test: (2.1) knowing for the sake of knowing; (2.2) knowing for the sake of doing; (2.3) not knowing.

CONCLUSIONS

The thrombophilia test is part of a larger network of meanings, where information about the test and its results seem to be lost.

PRACTICE IMPLICATION

The study suggests the importance of paying greater attention to the process of doctor-patient communication at the time of the test. The theme of being informed is important for patients, yet often they are not able to understand or retain the information they receive, increasing the risk of misunderstandings.

Pregnancy-associated venous thromboembolism: prevention and treatment

Pregnancy is associated with an increased risk of venous thromboembolism (VTE) and this condition remains an important cause of maternal morbidity and mortality. The use of anticoagulant therapy for treatment and prophylaxis of VTE during pregnancy is challenging because of the potential for fetal, as well as maternal, complications. Although evidence-based recommendations for the use of anticoagulants have been published, given the paucity of available data, guidelines are based largely upon observational studies and from data in nonpregnant patients. This article reviews the available literature and provides guidance for the management and prevention of VTE during pregnancy.

Is Thrombophilia Testing Useful?

Thrombophilia is found in many patients presenting with venous thromboembolism (VTE). However, whether the results of such tests help in the clinical management of such patients has not been determined. Thrombophilia testing in asymptomatic relatives may be useful in families with antithrombin, protein C, or protein S deficiency or homozygosity for factor V Leiden, but is limited to women who intend to become pregnant or who would like to use oral contraceptives. Careful counseling with knowledge of absolute risks helps patients in making an informed decision in which their own preferences can be taken into account. Observational studies show that patients who have had VTE and have thrombophilia are at most at a slightly increased risk for recurrence. In an observational study, the risk of recurrent VTE in patients who had been tested for inherited thrombophilia was not lower than in patients who had not been tested. In the absence of trials comparing routine and prolonged anticoagulant treatment in patients testing positive for thrombophilia, testing for such defects to prolong anticoagulant therapy cannot be justified. Diagnosing antiphospholipid syndrome (APS) in women with recurrent miscarriage usually leads to treatment with aspirin and low-molecular-weight heparin (LMWH), although the evidence to support this treatment is limited. Because testing for thrombophilia serves a limited purpose, this test should not be performed on a routine basis.

Evidence-based approach to thrombophilia testing

Thrombophilia can be identified in about half of all patients presenting with VTE. Testing has increased tremendously for various indications, but whether the results of such tests help in the clinical management of patients has not been settled. I use evidence from observational studies to conclude that testing for hereditary thrombophilia generally does not alter the clinical management of patients with VTE, with occasional exceptions for women at fertile age. Because testing for thrombophilia only serves limited purpose this should not be performed on a routine basis.

Role of investigating thrombophilic disorders in young stroke

Our knowledge about various inherited and acquired causes of thrombophilic disorders has increased significantly during the past decade. Technology for various diagnostic tests for these rare disorders has matched the rapid advances in our understanding about the thrombophilic disorders. Inherited thrombophilic disorders predispose young patients for various venous or arterial thrombotic and thromboembolic episodes. Our understanding has also improved about various gene-gene and gene-environment interactions and their impact on the resultant heterogenous clinical manifestations. We describe various thrombophilic disorders, their diagnostic tests, pathogenic potential in isolation or with other concurrent inherited/acquired defects and possible therapeutic and prophylactic strategies. Better understanding, optimal diagnostic and screening protocols are expected to improve the diagnostic yield and help to reduce morbidity, disability, and mortality in relatively younger patients harbouring these inherited and acquired thrombophilic disorders.

Thrombophilia screening--at the right time, for the right patient, with a good reason

Thrombophilia can be identified in about half of all patients presenting with venous thromboembolism (VTE). Thrombophilia screening for various indications has increased tremendously, but whether the results of such tests help in the clinical management of patients is uncertain. Here, current recommendations for thrombophilia screening in selected groups of patients, and considerations whether other high-risk subjects should be tested are reviewed. The methods for determination of the most common thrombophilic defects (antithrombin, protein C, protein S deficiencies, Factor V Leiden and prothrombin G20210A) associated with strong to moderate risk of VTE are described, indicating the timing and location of thrombophilia screening. Circumstances when a positive result of thrombophilia screening helps clinicians decide if adjustments of the anticoagulant regime are needed are discussed. Finally, psychological, social and ethical dilemmas associated with thrombophilia screening are indicated.

Points to consider in assessing and appraising predictive genetic tests

The use of predictive genetic tests is expanding rapidly. Given limited health care budgets and few national coverage decisions specifically for genetic tests, evidence of benefits and harms is a key requirement in decision making; however, assessing the benefits and harms of genetic tests raises a number of challenging issues. Frequently, evidence of medical benefits and harms is limited due to practical and ethical limitations of conducting meaningful clinical trials. Also, clinical endpoints frequently do not capture the benefit appropriately because the main purpose of many genetic tests is personal utility of knowing the test results, and costs of the tests and counseling can be insufficient indicators of the total costs of care. This study provides an overview of points to consider for the assessment of benefits and harms from genetic tests in an ethically and economically reflected manner. We discuss whether genetic tests are sufficiently exceptional to warrant exceptional methods for assessment and appraisal.

Testing for inherited thrombophilia does not reduce the recurrence of venous thrombosis

BACKGROUND

Inherited thrombophilia is only weakly associated with recurrence in patients with a first venous thrombosis (VT). In spite of this, thrombophilia testing is often performed in these patients. Positive results may influence patient management such as prolonged anticoagulant treatment or intensified prophylaxis in high-risk situations.

OBJECTIVE

To investigate whether thrombophilia testing reduces the risk of recurrent VT by virtue of these management alterations.

METHODS

From a large case-control study of patients (MEGA study), aged 18-70 years, with a first VT between 1999 and 2004, we selected 197 patients who had had a recurrence during follow-up. We compared the incidence of thrombophilia testing to that of a control cohort of 324 patients. We calculated the odds ratio (OR) for recurrent thrombosis in tested vs. non-tested patients. Only patients who were tested before recurrence were regarded as tested. All first and recurrent thrombotic events were objectively confirmed.

RESULTS

Thrombophilia tests were performed in 35% of cases and in 30% of controls. The OR for recurrence was 1.2 [95% confidence interval (CI) 0.9-1.8] for tested vs. non-tested patients. After correction for age, sex, family history, geographic region, presence of clinical risk factors, and year of first VT, the OR remained unchanged.

DISCUSSION

Thrombophilia testing in patients with a first VT does not reduce the incidence of recurrence in clinical practice.