Novel advances in cardiac rehabilitation : Position paper from the Working Group on Preventive Cardiology and Cardiac Rehabilitation of the Netherlands Society of Cardiology.

Cardiac rehabilitation (CR) has evolved as an important part of the treatment of patients with cardiovascular disease. However, to date, its full potential is fairly underutilised. This review discusses new developments in CR aimed at improving participation rates and long-term effectiveness in the general cardiac population. It consecutively highlights new or challenging target groups, new delivery modes and new care pathways for CR programmes. These new or challenging target groups include patients with atrial fibrillation, obesity and cardiovascular disease, chronic coronary syndromes, (advanced) chronic heart failure with or without intracardiac devices, women and frail elderly patients. Also, the current evidence regarding cardiac telerehabilitation and loyalty programmes is discussed as new delivery modes for CR. Finally, this paper discusses novel care pathways with the integration of CR in residual risk management and transmural care pathways. These new developments can help to make optimal use of the benefits of CR. Therefore we should seize the opportunities to reshape current CR programmes, broaden their applicability and incorporate them into or combine them with other cardiovascular care programmes/pathways.

Recommendations on how to provide cardiac rehabilitation services during the COVID-19 pandemic.

The ongoing coronavirus disease 2019 (COVID-19) crisis is having a large impact on acute and chronic cardiac care. Due to public health measures and the reorganisation of outpatient cardiac care, traditional centre-based cardiac rehabilitation is currently almost impossible. In addition, public health measures are having a potentially negative impact on lifestyle behaviour and general well-being. Therefore, the Working Group of Cardiovascular Prevention and Rehabilitation of the Dutch Society of Cardiology has formulated practical recommendations for the provision of cardiac rehabilitation during the COVID-19 pandemic, by using telerehabilitation programmes without face-to-face contact based on current guidelines supplemented with new insights and experiences.

Cardiac telerehabilitation as an alternative to centre-based cardiac rehabilitation.

Multidisciplinary cardiac rehabilitation (CR) reduces morbidity and mortality and increases quality of life in cardiac patients. However, CR utilisation rates are low, and targets for secondary prevention of cardiovascular disease are not met in the majority of patients, indicating that secondary prevention programmes such as CR leave room for improvement. Cardiac telerehabilitation (CTR) may resolve several barriers that impede CR utilisation and sustainability of its effects. In CTR, one or more modules of CR are delivered outside the environment of the hospital or CR centre, using monitoring devices and remote communication with patients. Multidisciplinary CTR is a safe and at least equally (cost-)effective alternative to centre-based CR, and is therefore recommended in a recent addendum to the Dutch multidisciplinary CR guidelines. In this article, we describe the background and core components of this addendum on CTR, and discuss its implications for clinical practice and future perspectives.

Using personas to tailor educational messages to the preferences of coronary heart disease patients.

PURPOSE: Although tailoring health education messages to individual characteristics of patients has shown promising results, most patient education materials still take a one-size-fits-all approach. The aim of this study was to develop a method for tailoring health education messages to patients' preferences for various message features, using the concept of personas. This is a preliminary study focused on education for coronary heart disease (CHD) patients. METHODS: This study used a three-step approach. First, we created personas by (i) performing k-means cluster analysis on data from an online survey that assessed the preferences of 213 CHD patients for various message features and, (ii) creating a vivid description of the preferences per patient cluster in an iterative process with the research team. Second, we developed adaptation rules to tailor existing educational messages to the resulting personas. Third, we conducted a pilot validation by adapting nine existing educational messages to each of the personas. These messages and the resulting personas were then presented to a separate group of 38 CHD patients who visited the cardiology outpatient clinic. They were first asked to choose their most preferred, second most preferred, and least preferred persona. Subsequently, they were asked to rate three of the adapted messages; one for every of the persona choices. RESULTS: We created five personas that pertained to five patient clusters. Personas varied mainly on preferences for medical or lay language, current or future temporal perspective, and including or excluding explicit health risks. Fifty-five different adaptation rules were developed, primarily describing adaptations to the message's perspective, level of detail, sentence structure, and terminology. Most participants in the validation study could identify with one of the five personas, although some of them found it hard to choose. On average, 68.5% of all participants rated the messages that matched their most preferred persona more positively than, or in the same way as, the messages that matched their least preferred persona. CONCLUSIONS: The persona-based method developed in this study can be used to create a manageable set of patient-centered tailored messages, while additionally using the developed personas to assess patients' preferences.

Exercise training programs in Dutch cardiac rehabilitation centres.

PURPOSE: To assess methods for determination of exercise intensity, and to investigate practice variation with respect to the contents, volume and intensity of exercise training programs in Dutch cardiac rehabilitation (CR) centres. METHODS: A paper questionnaire was sent to all Dutch CR centres, consisting of 85 questions for patients with an acute coronary syndrome (ACS) or after coronary revascularisation (Group 1) and for patients with chronic heart failure (CHF, Group 2). RESULTS: CR professionals from 45 centres completed the questionnaires (58 %). Symptom-limited exercise testing was used to determine exercise capacity in 76 % and 64 % of the CR centres in group 1 and group 2, respectively; in these centres, a percentage of the maximum heart rate was the most frequently used exercise parameter (65 % and 56 %, respectively). All CR centres applied aerobic training and the majority applied strength training (64 % in group 1 and 92 % in group 2, respectively). There was a considerable variation in training intensity for both aerobic and strength training, as well as in training volume (1-20 h and 1-18 h respectively). CONCLUSION: Among Dutch CR centres, considerable variation exists in methods for determination of exercise intensity. In addition, there is no uniformity in training volume and intensity.

Immunochemical fecal occult blood testing is equally sensitive for proximal and distal advanced neoplasia.

OBJECTIVE: Fecal immunochemical testing (FIT) is increasingly used for colorectal cancer (CRC) screening. We aimed to estimate its diagnostic accuracy in invitational population screening measured against colonoscopy. METHODS: Participants (50-75 years) in an invitational primary colonoscopy screening program were asked to complete one sample FIT before colonoscopy. We estimated FIT sensitivity, specificity, and predictive values in detecting CRC and advanced neoplasia (carcinomas and advanced adenomas) for cutoff levels of 50 (FIT50), 75 (FIT75), and 100 (FIT100) ng hemoglobin (Hb)/ml, corresponding with, respectively, 10, 15 and 20 µg Hb/g feces. RESULTS: A total of 1,256 participants underwent a FIT and screening colonoscopy. Advanced neoplasia was detected by colonoscopy in 119 (9%), 8 (0.6%) of them had CRC. At FIT50, 121 (10%) had a positive test result; 45 (37%) had advanced neoplasia and 7 (6%) had CRC. A total of 74 of 1,135 FIT50 negatives (7%) had advanced neoplasia including 1 (0.1%) CRC. FIT50 had a sensitivity of 38% (95% confidence interval (CI): 29-47) for advanced neoplasia and 88% (95% CI: 37-99) for CRC at a specificity of 93% (95% CI: 92-95) and 91% (95% CI: 89-92), respectively. The positive and negative predictive values for FIT50 were 6% (95% CI: 3-12) and almost 100% (95% CI: 99-100) for CRC, and 37% (95% CI: 29-46) and 93% (95% CI: 92-95) for advanced neoplasia. The sensitivity and specificity of FIT75 for advanced neoplasia were 33% (95% CI: 25-42) and 96% (95% CI: 94-97). At FIT100, 71 screenees (6%) had a positive test result. The sensitivity and specificity of FIT100 were for advanced neoplasia 31% (95% CI: 23-40) and 97% (95% CI: 96-98), and for CRC 75% (95% CI: 36-96) and 95% (95% CI: 93-96). The area under curve for detecting advanced neoplasia was 0.70 (95% CI: 0.64-0.76). FIT had a similar sensitivity for proximal and distal advanced neoplasia at cutoffs of 50 (38% vs. 37%; P=0.99), 75 (33% vs. 31%; P=0.85) and 100 (33% vs. 29%; P=0.68) ng Hb/ml. DISCUSSION: Nine out of ten screening participants with CRC and four out of ten with advanced neoplasia will be detected using one single FIT at low cutoff. Sensitivity in detecting proximal and distal advanced neoplasia is comparable.

Participation in a workplace web-based health risk assessment program.

BACKGROUND: Web-based health risk assessment (HRA) programs can be effective in primary prevention of cardiovascular diseases (CVD). Insight into determinants of participation could improve implementation in the workplace. AIMS: To evaluate determinants of participation and reasons for non-participation in a web-based HRA offered to 5125 employees at four Dutch financial and information technology services companies. METHODS: The study consisted of a questionnaire to compare sex, age, self-rated health, smoking, current work ability and sick leave between participants and non-participants in the HRA program, as well as reasons for non-participation. RESULTS: HRA participation rate was 37% (1907/5125) and 14% of the non-participants (423/3102) completed the non-participant questionnaire. There were no differences between participants and non-participants in sex, education level, smoking, and current work ability. Compared with non-participants, participants were older (44 versus 41 years, P < 0.001). Among participants, 85% rated their health as 'good' or 'very good', compared with 78% among non-participants (P < 0.001); 88% of the participants reported fewer than 10 days sickness absence in the previous year, compared with 86% of the non-participants (P < 0.05). Reported reasons for non-participation included lack of time (39%) and not being aware of the opportunity to participate (11%). CONCLUSIONS: Evaluation of demographic, health-related, and work-related determinants of participation in a web-based HRA showed differences between participants and non-participants in self-rated health and absenteeism. Implementing a less time-consuming HRA process and providing adequate information to employees prior to inviting them may be necessary to reach larger proportions of employees, including those with less favourable health and work characteristics.

Individualized duration of oral anticoagulant therapy for deep vein thrombosis based on a decision model.

BACKGROUND: The optimal duration of oral anticoagulant therapy for patients with a first episode of deep vein thrombosis (DVT) is still a matter of debate. However, according to the ACCP consensus strategy a limited stratification in treatment duration is advocated, i.e. 3 months for patients with a transient risk factor and 1 year or longer for patients with recurrent disease or a consistent risk factor such as thrombophilia or cancer. This consensus strategy is founded on the mean optimal duration of therapy obtained in large cohorts of patients and is mainly based on the risk of recurrent venous thromboembolism (VTE), with only minimal consideration for the patient's bleeding risk. OBJECTIVE: The aim of this study is to optimize the anticoagulant treatment strategy with vitamin K antagonists for the individual patient with DVT. METHODS: Based on an extensive literature study, a mathematical model was constructed to balance the risk of recurrent VTE against the risk of major hemorrhagic complications. The following parameters are incorporated in the model: baseline estimates and risk factors for recurrent VTE and bleeding, clinical course of DVT, and efficacy of treatment with vitamin K antagonists. With the use of these parameters, the risk for a recurrent VTE and a bleeding episode can be calculated for the individual patient. The optimal duration of anticoagulant therapy can be defined as the timepoint at which the benefit of treatment (prevention of VTE) is counterbalanced by its risk (bleeding). RESULTS/CONCLUSIONS: How long a patient should receive anticoagulant treatment is a matter of balancing the benefits and risks of treatment. The model shows that the optimal treatment duration varies greatly from patient to patient according to the patient's unique bleeding and recurrence risk.

Beta-receptor blockade decreases elevated plasma levels of factor VIII:C in patients with deep vein thrombosis.

BACKGROUND: An elevated plasma level of factor VIII:C (FVIII:C) is a strong and dose-dependent risk factor for venous thromboembolism (VTE). The cause of elevated FVIII:C in patients with thrombophilia is as yet unknown. FVIII:C increases significantly after infusion of epinephrine, vasopressin or physical exercise. The aim of the present study was to investigate whether beta-receptor blockade will lower sustained elevated FVIII:C in patients with VTE. METHODS AND RESULTS: Two cohorts of patients with documented deep vein thrombosis and an elevated FVIII:C (>175 IU dL(-1)) and healthy volunteers, were studied. One cohort was treated with the beta-receptor blocker, whereas the other cohort served as non-treatment controls. The patient treatment group and healthy volunteers were given 40 mg propranolol, thrice daily, for 14 days. The mean baseline level of FVIII:C was 220 IU dL(-1) and 102 IU dL(-1) in patients and healthy volunteers, respectively. After 2 weeks of propranolol a significant 23% reduction of FVIII:C (- 52 IU dL(-1); 95%CI:[-65; -39]) compared with no change over time in the patient no- treatment group (-1.8 IU dL(-1); 95%CI:[-34; 30]). After discontinuation of propranolol FVIII:C returned to its initial high level. In healthy volunteers propranolol had no effect on the plasma concentration of FVIII:C. CONCLUSION: This study demonstrates that in patients with VTE a sustained elevated FVIII:C concentration can be decreased with the use of propranolol. This observation may be of potential clinical relevance, since it has been shown that each increase of 10 IU dL(-1) in FVIII:C concentration enhanced the risk of a recurrent VTE by 24%.

High plasma concentration of factor VIIIc is a major risk factor for venous thromboembolism.

BACKGROUND: Established risk factors, including deficiencies of protein C, protein S or antithrombin and the factor V Leiden and prothrombin mutation, are present in about one third of unselected patients with venous thromboembolism. In addition to these inherited thrombophilic defects, elevated plasma levels of factor VIIIc have been suggested to be important in the pathogenesis of (recurrent) venous thromboembolism. The objective of this study was to assess the relevance of factor VIIIc plasma concentration in consecutive patients with venous thromboembolism. METHOD: We studied the prevalence of elevated plasma levels of factor VIIIc in 65 patients with a proven single episode and in 60 matched patients with documented recurrent venous thromboembolism. The reference group consisted of 60 age- and sex-matched patients who were referred for suspected venous thromboembolism, which was refuted by objective testing and long-term clinical follow-up. To minimalize the influence of the acute phase, blood was obtained at least 6 months after the thromboembolic event and results were adjusted for fibrinogen and C-reactive protein. Factor VIIIc was re-determined several years after the first measurement in a subset of patients to evaluate the variability over time. To study a possible genetic cause, a family study was done. FINDINGS: In the control, single and recurrent episode group, the prevalences of plasma levels of factor VIIIc above 175 IU/dl (90th percentile of controls) were 10% (95% CI: 4 to 21%), 19% (95% CI: 10 to 30%) and 33% (95% CI: 22 to 47%), respectively. For each 10 IU/dl increment of factor VIIIc, the risk for a single and recurrent episode of venous thrombosis increased by 10% (95% CI: 0.9 to 21%) and 24% (95% CI: 11 to 38%), respectively. Both low and high plasma levels of factor VIIIc were consistent over time (R = 0.80, p = 0.01). A family study indicated a high concordance for elevated factor VIIIc plasma concentrations among first degree family members. Adjustment for fibrinogen, C-reactive protein and known thrombophilic risk factors did not change the observed association of elevated factor VIIIc with thrombosis. INTERPRETATION: Elevated plasma levels of factor VIIIc are a significant, prevalent, independent and dose-dependent risk factor for venous thromboembolism. It also predisposes to recurrent venous thromboembolism.

Can causes of false-normal D-dimer test [SimpliRED] results be identified?

BACKGROUND: To simplify the diagnostic strategy of patients suspected for venous thromboembolism, the use of D-dimer tests has been advocated. Very important for the safety of such diagnostic strategies would be the capacity to recognise false-normal D-dimer results, in order to prevent inadequately withholding anticoagulant treatment in patients who actually have the disease. Insight in the causes of false-normal D-dimer results would therefore be necessary. We hypothesised that certain patient characteristics are associated with relatively low plasma D-dimer levels and, therefore, could increase the risk of false-normal results. METHODS: Consecutive patients with an objectively confirmed venous thromboembolic event and an independently obtained false-normal SimpliRED D-dimer test result were included in the study. For each patient, two controls with objectively confirmed venous thromboembolism and an adequate abnormal D-dimer result were selected. Baseline patient characteristics, obtained by standardised questionnaires, were compared between the two groups of patients. RESULTS: In total, 686 patients had a venous thromboembolic event and 47 of these patients had a false-normal SimpliRED result. Therefore, the overall sensitivity of the SimpliRED test for venous thromboembolism was 94% (95% CI: 92-95%). Although the prevalence of certain clinical characteristics was significantly higher in patients with a false-normal D-dimer result than in the controls [odds ratios for (LMW)heparin treatment and symptoms lasting more than 10 days: 5.1 (95% CI: 1.5-18.7) and 3.2 (95% CI:1.4-7.4), respectively], the prevalence of these characteristics was also high in the control group with an adequate abnormal D-dimer. Combining two or more of these characteristics had a low prevalence and did not further improve the ability to identify those patients with a false-normal D-dimer test at presentation. CONCLUSIONS: Although these findings clearly indicate an association between certain baseline clinical characteristics and the occurrence of a false-normal SimpliRED test, the clinical utility for these characteristics is limited.

Safety of treatment with oral anticoagulants in the elderly. A systematic review.

Oral anticoagulants have documented efficacy for many indications and are widely used in elderly patients. However, there is concern about whether this treatment induces an excess of major bleeding in elderly patients. In this systematic review, the incidence of oral anticoagulant-related major bleeding among elderly patients was determined. A total of 58 reports were identified that evaluated an oral anticoagulant, included patients with a mean age of at least 60 years, and provided data on the occurrence of major bleeding or provided separate data on the occurrence of major bleeding in elderly versus younger patients. In 50 studies no age differentiation was given. Although the incidence of bleeding complications varied, a trend towards increased bleeding with increasing age was shown in patients with major orthopaedic surgery and cardiac diseases. In the 8 articles that provided separate data on the occurrence of bleeding in different age categories, there was a clear tendency towards a 2-fold increase in bleeding in elderly patients. These findings emphasise the need for caution in the use of oral anticoagulants in elderly patients. However, the decision to start oral anticoagulant treatment should be based on an evaluation of the risk/benefit balance on a careful patient-by-patient basis. In general, if oral anticoagulant treatment is started, the lowest possible effective International Normalised Ratios (INR) should be selected and regular monitoring should be done to avoid over-anticoagulation.

Survey of the management of deep vein thrombosis in general practice in the Netherlands.

BACKGROUND: To investigate the management of (suspected) deep vein thrombosis in general practice. METHODS: Self completing postal questionnaire among a random sample of 692 general practitioners in the Netherlands. RESULTS: The overall response rate was 58%. Eighty-nine percent of the respondents initiated objective evaluation. Less than 3% usually make the diagnosis on clinical grounds only. Ninety-two percent initiated adequate treatment for the last patient with deep vein thrombosis. No more than 4% usually treat patients with acenocoumarol alone. Respondents frequently referred a patient to a specialist, 41% to confirm the diagnosis and 85% for treatment. Already 44% feel that management of deep vein thrombosis is a mandate of the general practitioner. For those who do not, the availability of diagnostic and therapeutic facilities are the main obstacles. CONCLUSION: In general practice objective diagnostic methods to evaluate suspected deep vein thrombosis are routinely used and patients receive adequate treatment. Although patients are frequently referred to the hospital many general practitioners feel that they should be able to take care of these patients themselves. (See Editorial p. 133)

Requirements for appropriate evaluation of diagnostic tests in suspected pulmonary embolism.

In contrast to the development of new drugs, strict guidelines for the development of new diagnostic methods do not exist. A diagnostic test can be made available without proper evaluation of its clinical utility, which can lead to its premature introduction and inappropriate use. In this review suggestions are made regarding the criteria that should be met during the various phases of development of new diagnostic techniques. It is suggested that a new diagnostic test should only be implemented in routine clinical use after all phases of development have been properly performed with good results. Several diagnostic tests for pulmonary embolism (pulmonary angiography, ventilation-perfusion scintigraphy, D-dimer assays, and spiral computed tomography), and the studies evaluating them, are thereafter reviewed. It is concluded that present pulmonary angiography and ventilation-perfusion scintigraphy are the only properly evaluated diagnostic tests for pulmonary embolism. Although new developments, such as D-dimer assays and the spiral computed tomographic scan are certainly promising, further studies are needed to determine their real value and safety in the diagnostic work-up of patients suspected of pulmonary embolism.

[Long flights and the risk of venous thrombosis]. / Lange vliegreizen en het risico op veneuze trombose.

It is pathophysiologically conceivable that prolonged air travel may lead to blood flow stasis and hypercoagulability of the blood. The available observational and case-control studies do not, however, indicate an increased incidence of venous thromboembolism amongst air travellers. In these studies bias may have been caused by patients visiting their own GP instead of the airport medical services, the omission of an objective test to establish the thrombosis, the selection of control patients with a different travel behaviour or the inclusion of flying times that were too short. If in the future it becomes apparent that patients with an increased likelihood of thrombosis risk developing venous thromboembolism as a result of prolonged air travel then preventive measures may be required. These could include short-term thrombosis prophylaxis or the wearing of special elastic stockings. Furthermore, all air travellers should be advised to keep moving during long flights and to drink plenty, preferably non-alcoholic beverages.

Exclusion of deep vein thrombosis using the Wells rule in clinically important subgroups: individual patient data meta-analysis.

OBJECTIVE: To assess the accuracy of the Wells rule for excluding deep vein thrombosis and whether this accuracy applies to different subgroups of patients. DESIGN: Meta-analysis of individual patient data. DATA SOURCES: Authors of 13 studies (n = 10,002) provided their datasets, and these individual patient data were merged into one dataset. ELIGIBILITY CRITERIA: Studies were eligible if they enrolled consecutive outpatients with suspected deep vein thrombosis, scored all variables of the Wells rule, and performed an appropriate reference standard. MAIN OUTCOME MEASURES: Multilevel logistic regression models, including an interaction term for each subgroup, were used to estimate differences in predicted probabilities of deep vein thrombosis by the Wells rule. In addition, D-dimer testing was added to assess differences in the ability to exclude deep vein thrombosis using an unlikely score on the Wells rule combined with a negative D-dimer test result. RESULTS: Overall, increasing scores on the Wells rule were associated with an increasing probability of having deep vein thrombosis. Estimated probabilities were almost twofold higher in patients with cancer, in patients with suspected recurrent events, and (to a lesser extent) in males. An unlikely score on the Wells rule (≤ 1) combined with a negative D-dimer test result was associated with an extremely low probability of deep vein thrombosis (1.2%, 95% confidence interval 0.7% to 1.8%). This combination occurred in 29% (95% confidence interval 20% to 40%) of patients. These findings were consistent in subgroups defined by type of D-dimer assay (quantitative or qualitative), sex, and care setting (primary or hospital care). For patients with cancer, the combination of an unlikely score on the Wells rule and a negative D-dimer test result occurred in only 9% of patients and was associated with a 2.2% probability of deep vein thrombosis being present. In patients with suspected recurrent events, only the modified Wells rule (adding one point for the previous event) is safe. CONCLUSION: Combined with a negative D-dimer test result (both quantitative and qualitative), deep vein thrombosis can be excluded in patients with an unlikely score on the Wells rule. This finding is true for both sexes, as well as for patients presenting in primary and hospital care. In patients with cancer, the combination is neither safe nor efficient. For patients with suspected recurrent disease, one extra point should be added to the rule to enable a safe exclusion.

Improving guideline adherence for cardiac rehabilitation in the Netherlands.

BACKGROUND: In 2004, the Netherlands Society of Cardiology released the current guideline on cardiac rehabilitation. Given its complexity and the involvement of various healthcare disciplines, it was supplemented with a clinical algorithm, serving to facilitate its implementation in daily practice. Although the algorithm was shown to be effective for improving guideline adherence, several shortcomings and deficiencies were revealed. Based on these findings, the clinical algorithm has now been updated. This article describes the process and the changes that were made. METHODS: The revision consisted of three phases. First, the reliability of the measurement instruments included in the 2004 Clinical Algorithm was investigated by evaluating between-centre variations of the baseline assessment data. Second, based on the available evidence, a multidisciplinary expert advisory panel selected items needing revision and provided specific recommendations. Third, a guideline development group decided which revisions were finally included, also taking practical considerations into account. RESULTS: A total of nine items were revised: three because of new scientific insights and six because of the need for more objective measurement instruments. In all revised items, subjective assessment methods were replaced by more objective assessment tools (e.g. symptom-limited exercise instead of clinical judgement). In addition, four new key items were added: screening for anxiety/depression, stress, cardiovascular risk profile and alcohol consumption. CONCLUSION: Based on previously determined shortcomings, the Clinical Algorithm for Cardiac Rehabilitation was thoroughly revised mainly by incorporating more objective assessment methods and by adding several new key areas.

Early discharge strategies following venous thrombosis.

Low-molecular-weight heparin therapy is administered subcutaneously, not intravenously. This has made possible the management of selected patients who have acute deep venous thrombosis as outpatients. Others can be treated with an abbreviated several day hospitalization rather than the conventional 5 or more hospital days needed for administration of continuous intravenous unfractionated heparin. Two large studies, Tasman and a Canadian trial, have demonstrated the efficacy and safety of low-molecular-weight heparin in this setting. Now, the task is to develop guidelines for widespread application of these findings to daily clinical practice. However, successful home treatment will require intensive patient education as well as an extensive infrastructure of supportive nursing and physician services. Careful patient follow-up will be crucially important.

Travel and risk of venous thrombosis.

In 1998 the term economy class syndrome was coined to describe the association between travel and thrombosis. A fair risk estimate, however, has not been done. We report the results of a prospective study, in which we kept the effect of bias to a minimum. We compared travel history in 788 patients with venous thrombosis with that of controls with similar symptoms but in whom the disease had been excluded. For air travel alone, the odds ratio was 1.0 (95% CI 0.3-3.0); also, no association was recorded for other methods of transportation. We have shown that, there is no increased risk of deep vein thrombosis among travellers.