Deep venous thrombosis: a new task for primary health care. A randomised economic study of outpatient and inpatient treatment

[Translated article] Rivaroxaban versus enoxaparin for thromboprophylaxis in orthopedic surgery: A meta-analysis

INTRODUCTION

Venous thromboembolism is highly associated with orthopedic surgery, so thromboprophylaxis is an important consideration for orthopedic surgeons. The new oral anticoagulants have clear advantages for clinical practice.

OBJECTIVES

To analyze the efficacy and safety of rivaroxaban versus enoxaparin for thromboprophylaxis in different orthopedic surgeries.

MATERIAL AND METHODS

Systematic electronic search of clinical trials was carried out. Data extraction of efficacy outcomes (deep venous thrombosis, pulmonary embolism and death) and safety outcomes (major bleeding and clinically relevant bleeding) was realized.

RESULTS

Six randomized and controlled clinical trials were included in this meta-analysis. Compared with enoxaparin the risk of venous thromboembolism was lower with rivaroxaban both in different orthopedic surgeries (RR: 0.51; 95% CI: 0.36-0.73; p=.0002). This result was even better and more homogeneous in the analysis of symptomatic deep venous thrombosis outcome (RR: 0.43; 95% CI: 0.28-0.65; p<.0001; I2=0%; p=.49). The risk of bleeding was not significantly higher with rivaroxaban (RR: 1.20; 95% CI: 0.97-1.49; p=.09).

CONCLUSIONS

Rivaroxaban should be considerate such as a more effective alternative for thromboprophylaxis in orthopedic surgery.

Rivaroxaban versus enoxaparin for thromboprophylaxis in orthopedic surgery: A meta-analysis

INTRODUCTION

Venous thromboembolism is highly associated with orthopedic surgery, so thromboprophylaxis is an important consideration for orthopedic surgeons. The new oral anticoagulants have clear advantages for clinical practice.

OBJECTIVES

To analyze the efficacy and safety of rivaroxaban versus enoxaparin for thromboprophylaxis in different orthopedic surgeries.

MATERIAL AND METHODS

Systematic electronic search of clinical trials was carried out. Data extraction of efficacy outcomes (deep venous thrombosis, pulmonary embolism and death) and safety outcomes (major bleeding and clinical relevant bleeding) was realized.

RESULTS

Six randomized and controlled clinical trials were included in this meta-analysis. Compared with enoxaparin the risk of venous thromboembolism was lower with rivaroxaban both in different orthopedic surgeries (RR: 0.51; 95% CI: 0.36-0.73; P=.0002). This result was even better and more homogeneous in the analysis of symptomatic deep venous thrombosis outcome (RR: 0.43; 95% CI: 0.28-0.65; P<.0001; I2=0%; P=.49). The risk of bleeding was not significantly higher with rivaroxaban (RR: 1.20; 95% CI: 0.97-1.49; P=.09).

CONCLUSIONS

Rivaroxaban should be considerate such as a more effective alternative for thromboprophylaxis in orthopedic surgery.

90-Day readmission after radical prostatectomy-a prospective comparison between robot-assisted and open surgery

Purpose: All types of surgery are associated with complications. The debate is ongoing whether robot-assisted radical prostatectomy can lower this risk compared to open surgery. The objective of the present study was to evaluate post-operative adverse events leading to readmissions, using clinical records to classify these adverse events systematically. Materials and methods: A prospective controlled trial of men who underwent robot-assisted laparoscopic (RALP) or retropubic radical prostatectomy (RRP) at 14 departments of Urology (LAPPRO) between 2008 and 2011. Data on all readmissions within 3 months of surgery were collected from the Patient registry, Swedish Board of Health and Welfare. For each readmission the highest Clavien-Dindo grade was listed. Results: A total of 4003 patients were included in the LAPPRO trial and, after applying exclusion criteria, 3706 patients remained for analyses. The results showed no statistically significant difference in the overall readmission rates (8.1 vs. 7.1%) or readmission due to major complications (Clavien-Dindo ≥3b, 1.7 vs. 1.9%) between RALP and RRP within 90 days after surgery. Patients subjected to lymph-node dissection (LND) had twice the risk for readmission as men not undergoing LND, irrespective RALP or RRP technique. Blood transfusion was significantly more frequent during and within 30 days of RRP surgery (16 vs. 4%). Abdominal symptoms were more common after RALP. Conclusions: There is a substantial risk for hospital readmission after prostate-cancer surgery, regardless of technique; although major complications are rare. Regardless of surgical technique, attention should be focused on specific types of complications.

Home versus in-patient treatment for deep vein thrombosis

BACKGROUND

Deep vein thrombosis (DVT) occurs when a blood clot blocks blood flow through a vein, which can occur after surgery, after trauma, or when a person has been immobile for a long time. Clots can dislodge and block blood flow to the lungs (pulmonary embolism (PE)), causing death. DVT and PE are known by the term venous thromboembolism (VTE). Heparin (in the form of unfractionated heparin (UFH)) is a blood-thinning drug used during the first three to five days of DVT treatment. Low molecular weight heparins (LMWHs) allow people with DVT to receive their initial treatment at home instead of in hospital. This is an update of a review first published in 2001 and updated in 2007.

OBJECTIVES

To compare the incidence and complications of venous thromboembolism (VTE) in patients treated at home versus patients treated with standard in-patient hospital regimens. Secondary objectives included assessment of patient satisfaction and cost-effectiveness of treatment.

SEARCH METHODS

For this update, the Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register (last searched 16 March 2017), the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 2), and trials registries. We also checked the reference lists of relevant publications.

SELECTION CRITERIA

Randomised controlled trials (RCTs) examining home versus hospital treatment for DVT, in which DVT was clinically confirmed and was treated with LMWHs or UFH.

DATA COLLECTION AND ANALYSIS

One review author selected material for inclusion, and another reviewed the selection of trials. Two review authors independently extracted data and assessed included studies for risk of bias. Primary outcomes included combined VTE events (PE and recurrent DVT), gangrene, heparin complications, and death. Secondary outcomes were patient satisfaction and cost implications. We performed meta-analysis using fixed-effect models with risk ratios (RRs) and 95% confidence intervals (CIs) for dichotomous data.

MAIN RESULTS

We included in this review seven RCTs involving 1839 randomised participants with comparable treatment arms. All seven had fundamental problems including high exclusion rates, partial hospital treatment of many in the home treatment arms, and comparison of UFH in hospital versus LMWH at home. These trials showed that patients treated at home with LMWH were less likely to have recurrence of VTE events than those given hospital treatment with UFH or LMWH (fixed-effect risk ratio (RR) 0.58, 95% confidence interval (CI) 0.39 to 0.86; 6 studies; 1708 participants; P = 0.007; low-quality evidence). No clear difference was seen between groups for major bleeding (RR 0.67, 95% CI 0.33 to 1.36; 6 studies; 1708 participants; P = 0.27; low-quality evidence), minor bleeding (RR 1.29, 95% CI 0.94 to 1.78; 6 studies; 1708 participants; P = 0.11; low-quality evidence), or mortality (RR 0.69, 95% CI 0.44 to 1.09; 6 studies; 1708 participants; P = 0.11; low-quality evidence). The included studies reported no cases of venous gangrene. We could not combine patient satisfaction and quality of life outcomes in meta-analysis owing to heterogeneity of reporting, but two of three studies found evidence that home treatment led to greater improvement in quality of life compared with in-patient treatment at some point during follow-up, and the third study reported that a large number of participants chose to switch from in-patient care to home-based care for social and personal reasons, suggesting it is the patient's preferred option (very low-quality evidence). None of the studies included in this review carried out a full cost-effectiveness analysis. However, a small randomised economic evaluation of the two alternative treatment settings involving 131 participants found that direct costs were higher for those in the in-patient group. These findings were supported by three other studies that reported on their costs (very low-quality evidence).Quality of evidence for data from meta-analyses was low to very low. This was due to risk of bias, as many of the included studies used unclear randomisation techniques, and blinding was a concern for many. Also, indirectness was a concern, as most studies included a large number of participants randomised to the home (LMWH) treatment group who were treated in hospital for some or all of the treatment period. A further issue for some outcomes was heterogeneity that was evident in measurement and reporting of outcomes.

AUTHORS' CONCLUSIONS

Low-quality evidence suggests that patients treated at home with LMWH are less likely to have recurrence of VTE than those treated in hospital. However, data show no clear differences in major or minor bleeding, nor in mortality (low-quality evidence), indicating that home treatment is no worse than in-patient treatment for these outcomes. Because most healthcare systems are moving towards more LMWH usage in the home setting it is unlikely that additional large trials will be undertaken to compare these treatments. Therefore, home treatment is likely to become the norm, and further research will be directed towards resolving practical issues by devising local guidelines that include clinical prediction rules, developing biomarkers and imaging that can be used to tailor therapy to disease severity, and providing training for community healthcare workers who administer treatment and monitor treatment progress.

The Saudi Clinical Practice Guideline for the treatment of venous thromboembolism. Outpatient versus inpatient management

Venous thromboembolism (VTE) including deep vein thrombosis (DVT) and pulmonary embolism (PE) is commonly encountered in daily clinical practice. After diagnosis, its management frequently carries significant challenges to the clinical practitioner. Treatment of VTE with the inappropriate modality and/or in the inappropriate setting may lead to serious complications and have life-threatening consequences. As a result of an initiative of the Ministry of Health of the Kingdom of Saudi Arabia, an expert panel led by the Saudi Association for Venous Thrombo-Embolism (a subsidiary of the Saudi Thoracic Society) and the Saudi Scientific Hematology Society with the methodological support of the McMaster University Guideline working group, this clinical practice guideline was produced to assist health care providers in VTE management. Two questions were identified and were related to the inpatient versus outpatient treatment of acute DVT, and the early versus standard discharge from hospital for patients with acute PE. The corresponding recommendations were made following the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) approach.

Plasma MMP and TIMP evaluation in patients with deep venous thrombosis: could they have a predictive role in the development of post-thrombotic syndrome?

Post-thrombotic syndrome (PTS) is a condition that can develop in about half of the patients with deep vein thrombosis (DVT) of lower limbs. In the present study, we evaluated the expression of inflammatory biomarkers in the early phases of DVT and their correlation with the onset of PTS. Patients were enrolled after the first episode of DVT and were followed up for 1, 4, 8, 12 and 18 months. At each visit, blood sample was collected to evaluate plasma levels of matrix metalloproteinase (MMP)-1,-2,-3,-7,-8 and -9 MMP inhibitors, TIMP-1,-2, neutrophil gelatinase-associated lipocalin (NGAL) and cytokines TNF-α and IL-6. Analysis included 201 patients [86 males (42·79%) and 115 females (57·21%); average age 56 ± 7 years]. Of the 201 patients, 47 (23·38%; 21 males, 26 females) developed PTS during the follow-up period. The control group was made up of 60 individuals without DVT (22 males and 38 females). High plasma levels of MMPs, NGAL and cytokines were recorded during the acute phase after DVT. Moreover, patients with PTS showed higher levels of MMP-1 and MMP-8 with respect to patients without PTS. There is a close relationship between DVT, the individual risk of PTS and specific biomarkers such as MMPs and other related molecules, which may help guide prevention and therapy based on the patient's individual risk profile, and has to be studied in future.

Prophylaxis and treatment of venous thromboembolism in patients with cancer: the Saudi clinical practice guideline

BACKGROUND AND OBJECTIVES

Venous thromboembolism (VTE) is commonly encountered in the daily clinical practice. Cancer is an important VTE risk factor. Proper thromboprophylaxis is key to prevent VTE in patients with cancer, and proper treatment is essential to reduce VTE complications and adverse events associated with the therapy.

DESIGN AND SETTINGS

As a result of an initiative of the Ministry of Health of Saudi Arabia, an expert panel led by the Saudi Association for Venous Thrombo-Embolism (a subsidiary of the Saudi Thoracic Society) and the Saudi Scientific Hematology Society with the methodological support of the McMaster University working group produced this clinical practice guideline to assist health care providers in evidence-based clinical decision-making for VTE prophylaxis and treatment in patients with cancer.

METHODS

Six questions related to thromboprophylaxis and antithrombotic therapy were identified and the corresponding recommendations were made following the GRADE (Grading of Recommendations, Assessment, Development and Evaluation) approach.

RESULTS

Question 1. Should heparin versus no heparin be used in outpatients with cancer who have no other therapeutic or prophylactic indication for anticoagulation?

RECOMMENDATION

For outpatients with cancer, the Saudi Expert Panel suggests against routine thromboprophylaxis with heparin (weak recommendation; moderate quality evidence).Question 2. Should oral anticoagulation versus no oral anticoagulation be used in outpatients with cancer who have no other therapeutic or prophylactic indication for anticoagulation?

RECOMMENDATION

For outpatients with cancer, the Saudi Expert Panel recommends against thromboprophylaxis with oral anticoagulation (strong recommendation; moderate quality evidence).Question 3. Should parenteral anticoagulation versus no anticoagulation be used in patients with cancer and central venous catheters?

RECOMMENDATION

For outpatients with cancer and central venous catheters, the Saudi Expert Panel suggests thromboprophylaxis with parenteral anticoagulation (weak recommendation; moderate quality evidence).Question 4. Should oral anticoagulation versus no anticoagulation be used in patients with cancer and central venous catheters?

RECOMMENDATION

For outpatients with cancer and central venous catheters, the Saudi Expert Panel suggests against thromboprophylaxis with oral anticoagulation (weak recommendation; low quality evidence).Question 5. Should low-molecular-weight heparin versus unfractionated heparin be used in patients with cancer being initiated on treatment for venous thromboembolism?

RECOMMENDATION

In patients with cancer being initiated on treatment for venous thromboembolism, the Saudi Expert Panel suggests low-molecular-weight heparin over intravenous unfractionated heparin (weak; very low quality evidence).Question 6. Should heparin versus oral anticoagulation be used in patients with cancer requiring long-term treatment of VTE?

RECOMMENDATION

In patients with metastatic cancer requiring long-term treatment of VTE, the Saudi Expert Panel recommends low-molecular-weight heparin (LMWH) over vitamin K antagonists (VKAs) (strong recommendation; moderate quality evidence). In patients with non-metastatic cancer requiring long-term treatment of venous thromboembolism, the Saudi Expert Panel suggests LMWH over VKA (weak recommendation; moderate quality evidence).

Symptom burden and job absenteeism after treatment with additional catheter-directed thrombolysis for deep vein thrombosis

Introduction

Additional catheter-directed thrombolysis (CDT) for acute deep vein thrombosis (DVT) reduces long-term postthrombotic syndrome and is likely to represent a cost-effective alternative treatment compared to the standard treatment of anticoagulation and elastic compression stockings. Accelerated thrombus resolution has also been suggested to improve symptoms and patient function in the acute phase. We aimed to investigate whether additional CDT led to fewer symptoms and job absenteeism during the first 6 months after initiation of DVT treatment compared to standard treatment alone.

Methods

The Catheter-directed Venous Thrombolysis (CaVenT) study was a multicenter open label, randomized controlled trial of patients ages 18 years to 75 years with a verified high proximal DVT, <21 days of symptoms, and no apparent bleeding risk. Patients were allocated to additional CDT or to standard treatment only. Symptoms were assessed at baseline and at 6 months using items from the generic and disease-specific quality of life questionnaires EQ-5D and VEINES-QOL/Sym, respectively. Individual data on sickness benefits related to venous thromboembolic disease were obtained from the national welfare service.

Results

A total of 90 patients allocated additional CDT and 99 control patients completed long-term follow-up and were included in the analyses. Twenty-four in the CDT arm and 40 controls received sick leave (P = 0.046). When considering working patients only (54 in the CDT arm and 72 controls) this difference was no longer statistically significant. Mean duration of job absenteeism was 86.4 days (95% confidence interval 59.4–113.5) in the CDT arm and 60.1 days (95% confidence interval 42.3–77.8) in controls (P = 0.072). After 6 months, more controls experienced frequent swelling of the leg compared with those allocated to CDT (47 [49.0%] patients versus 25 [29.4%] patients, respectively, [P = 0.007]).

Conclusion

There are limitations to our data, but the findings indicate improved symptom relief and less frequent job absenteeism in patients treated with additional CDT; this expands upon previously established benefits from this treatment.

A review on state-of-the-art data regarding safe early discharge following admission for pulmonary embolism: what do we know?

BACKGROUND

Although most patients with acute pulmonary embolism (PE) remain hospitalized during initial therapy, some may be suitable for partial or complete outpatient management, which may have a significant impact on healthcare costs.

HYPOTHESIS

This article reviews the state-of-the-art data regarding recognition of very-low-risk PE patients who are potentially eligible for outpatient treatment, along with the safety, management, and cost-effectiveness of this strategy. We propose an algorithm based on collected data that may be useful/practical for identifying patients truly eligible for early discharge.

METHODS

Comprehensive review of scientific data collected from the MEDLINE and Cochrane databases. Studies selected based on potential scientific interest. Qualitative information extracted regarding feasibility, safety, and cost-effectiveness of outpatient treatment, postdischarge management, and selection of truly low-risk patients.

RESULTS

Early discharge of low-risk patients seems feasible, safe, and particularly cost-effective. Several risk scores have been developed and/or tested as prediction tools for the recognition of low-risk individuals: the Pulmonary Embolism Severity Index (PESI), simplified PESI, Hestia criteria, Geneva score, the Low-Risk Pulmonary Embolism Decision rule, and the Global Registry of Acute Cardiac Events, among others. PESI is the most well-validated model, offering the safest approach at the current time, especially when combined with additional parameters such as troponin I, N-terminal prohormone of brain natriuretic peptide, and echocardiographic markers of right-ventricular dysfunction.

CONCLUSIONS

Recognition of truly low-risk patients entitled to early hospital discharge and outpatient treatment is possible with current risk-stratification schemes along with selected prognostic parameters, and it may have a colossal impact on healthcare costs.

Cost-effectiveness impact of rivaroxaban versus new and existing prophylaxis for the prevention of venous thromboembolism after total hip or knee replacement surgery in France, Italy and Spain

Venous thromboembolism (VTE) has a significant impact on healthcare costs but is largely preventable with anticoagulant prophylaxis using low-molecular-weight heparins (LMWHs), such as enoxaparin or dalteparin. Rivaroxaban and dabigatran etexilate are two new oral anticoagulants (NOACs) both compared with enoxaparin in separate trials. A decision analytic model with a healthcare and national payer perspective over a five-year time horizon was used to evaluate the cost-effectiveness of the NOACs for VTE prophylaxis after total hip replacement (THR) or total knee replacement (TKR) in France, Italy and Spain. Efficacy and safety data were obtained from randomised controlled trials of rivaroxaban vs enoxaparin and an indirect statistical comparison for rivaroxaban vs dabigatran. Rivaroxaban demonstrated dominance across all comparisons, indications and countries. In THR, total per-patient costs were reduced by up to €160 in the enoxaparin comparison and €115 in the dabigatran comparison, respectively. In addition, quality-adjusted life-years (QALYs) were increased by up to 0.0011 and 0.0012 in each comparison, respectively. Similarly, total costs were reduced in TKR by up to €137 and €28 in the enoxaparin and dabigatran comparisons, respectively. The total number of QALYs was increased by up to 0.0014 in the enoxaparin comparison and 0.0005 in the dabigatran comparison. The results were driven by costs since the incremental benefits were minimal. Rivaroxaban use could result in substantial healthcare cost savings and improved quality of life. The results are applicable across three European countries with differing healthcare systems so, potentially, could be generalised to a much wider population.

Antithrombotic therapy for VTE disease: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines

BACKGROUND

This article addresses the treatment of VTE disease.

METHODS

We generated strong (Grade 1) and weak (Grade 2) recommendations based on high-quality (Grade A), moderate-quality (Grade B), and low-quality (Grade C) evidence.

RESULTS

For acute DVT or pulmonary embolism (PE), we recommend initial parenteral anticoagulant therapy (Grade 1B) or anticoagulation with rivaroxaban. We suggest low-molecular-weight heparin (LMWH) or fondaparinux over IV unfractionated heparin (Grade 2C) or subcutaneous unfractionated heparin (Grade 2B). We suggest thrombolytic therapy for PE with hypotension (Grade 2C). For proximal DVT or PE, we recommend treatment of 3 months over shorter periods (Grade 1B). For a first proximal DVT or PE that is provoked by surgery or by a nonsurgical transient risk factor, we recommend 3 months of therapy (Grade 1B; Grade 2B if provoked by a nonsurgical risk factor and low or moderate bleeding risk); that is unprovoked, we suggest extended therapy if bleeding risk is low or moderate (Grade 2B) and recommend 3 months of therapy if bleeding risk is high (Grade 1B); and that is associated with active cancer, we recommend extended therapy (Grade 1B; Grade 2B if high bleeding risk) and suggest LMWH over vitamin K antagonists (Grade 2B). We suggest vitamin K antagonists or LMWH over dabigatran or rivaroxaban (Grade 2B). We suggest compression stockings to prevent the postthrombotic syndrome (Grade 2B). For extensive superficial vein thrombosis, we suggest prophylactic-dose fondaparinux or LMWH over no anticoagulation (Grade 2B), and suggest fondaparinux over LMWH (Grade 2C).

CONCLUSION

Strong recommendations apply to most patients, whereas weak recommendations are sensitive to differences among patients, including their preferences.

Economic burden of venous thromboembolism: a systematic review

OBJECTIVE

Deep vein thrombosis and pulmonary embolism - together referred to as venous thromboembolism (VTE) - result in a major burden on healthcare systems. However, to the authors' knowledge no comprehensive review of the economic burden of VTE has so far been published.

METHODS

A literature search was carried out to identify references published in English since 1997 using Medline, the Cochrane Library and the Health Economic Evaluations Database. The primary outcomes of interest were 'all-cause' VTE and VTE after major orthopedic surgery.

RESULTS

A total of 1,037 full research articles and abstracts were screened for inclusion in the review. Of these, ten cost-of-illness studies were identified that met the inclusion criteria and are included in the current review. The results of large US database analyses vary, indicating costs of the initial VTE of approximately US$3,000-9,500. The total costs related to VTE over 3 months (US$5,000), 6 months (US$10,000) and 1 year (US$33,000) were considerable. Studies conducted in the European Union indicate lower additional inpatient costs after VTE of €1,800 after 3 months and €3,200 after 1 year, which still represent a considerable impact on healthcare systems. Complications after VTE can be very expensive, with estimates of the additional cost of treating the post-thrombotic syndrome ranging from $426 to $11,700 and heparin-induced thrombocytopenia from $3,118 to $41,133. A limitation of studies using older data is that recent changes in the treatment of VTE may affect the generalizability of these findings.

CONCLUSIONS

Complications associated with VTE are frequent and costly. In particular, the cost of complications resulting from prophylaxis and treatment of VTE, such as post-thrombotic syndrome and heparin-induced thrombocytopenia, had a considerable economic impact.

Cost-effectiveness of venous thromboembolism prophylaxis in total hip and knee replacement surgery: the evolving application of health economic modelling over 20 years

OBJECTIVES

In the last two decades, there has been considerable evolution of methods for cost-effectiveness modelling. Some of the first models were developed in the area of venous thromboembolism (VTE) prophylaxis. Hence, this area can serve as an important example to illustrate evolving standards. Our objectives are to document evolving methodology by describing VTE models, assess their critical strengths and weaknesses, and inform future advances for models in this therapeutic area.

RESEARCH DESIGN AND METHODS

A systematic review of economic models of primary VTE prevention following hip and knee replacement surgery was undertaken. Electronic searches of PubMed, EMBASE, the Cochrane library, and grey literature were conducted (1985-2006). Reference lists of included articles and reviews were examined for relevant studies.

RESULTS

Twenty-nine cost-effectiveness models were identified. Nineteen other cost-effectiveness analyses were excluded because they were not model-based; 16 were simple cost calculations and three were analyses of resource use data collected alongside clinical trials. The majority of models (24) were constructed as decision trees, frequently utilising previously published model structures, with some adaptation for new comparators, and/or addition of relevant events omitted by earlier models (e.g., bleeding due to prophylactic treatment). Later models have included Markov processes to model potential long-term consequences of VTE (recurrent VTE and post-thrombotic syndrome) over longer time horizons. Systematic identification of clinical evidence and more sophisticated analysis methods (e.g., Bayesian mixed-treatment comparisons and probabilistic sensitivity analyses) have recently been introduced.

CONCLUSIONS

Model structures have evolved substantially in this highly studied therapeutic area, with improvements made to the model structure, the comprehensiveness of clinical evidence included, and the underlying calculation methodology.

Home versus in-patient treatment for deep vein thrombosis

BACKGROUND

Deep vein thrombosis (DVT) occurs when a blood clot blocks blood flow through a vein. This can happen after surgery, trauma, or when a person has been immobile. Clots can dislodge and block blood flow to the lungs, causing death. Heparin is a blood-thinning drug used in the first 3-5 days of DVT treatment. Low molecular weight heparins (LMWH) allow people with DVT to receive their initial treatment at home instead of in hospital.

OBJECTIVES

To collate randomised controlled trials (RCTs) comparing home (LMWH) versus hospital (LMWH or UH) treatment for DVT, and to compare the safety, efficacy, acceptability and cost implications of home versus hospital treatment.

SEARCH STRATEGY

We searched the Cochrane Peripheral Vascular Diseases Group trials register (inception to May 2007) and the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library (last searched Issue 2, 2007) which includes searches of MEDLINE (January 1966 onwards) and EMBASE (January 1980 onwards). We also handsearched non-listed journals and contacted researchers in the field.

SELECTION CRITERIA

RCTs of home versus hospital treatment for DVT in which DVT was clinically confirmed and treated with either LMWH or UH.

DATA COLLECTION AND ANALYSIS

One reviewer selected the material for inclusion and another reviewed the literature and selection of trials. Two reviewers independently extracted data. Outcomes included PE, recurrent DVT, gangrene, heparin complications, and death.

MAIN RESULTS

Six RCTs involving 1708 participants with comparable treatment arms were included. All six had fundamental problems including high exclusion rates, partial hospital treatment of many in the LMWH arms, and comparison of UH in hospital with LMWH at home. The trials showed that patients treated at home with LMWH are less likely to have recurrence of venous thromboembolism (VTE) compared to hospital treatment with UH or LMWH (fixed effect relative risk (FE RR) 0.61; 95% confidence interval (CI) 0.42 to 0.90). Home treated patients also had lower mortality (FE RR 0.72; 95% CI 0.45 to 1.15) and fewer major bleeding (FE RR 0.67; 95% CI 0.33 to 1.36), but were more likely to have minor bleeding than those in hospital (FE RR 1.29; 95% CI 0.94 to 1.78) though these were not statistically significant.

AUTHORS' CONCLUSIONS

The limited evidence suggests that home management is cost effective and preferred by patients. Further large trials comparing these treatments are unlikely to occur. Therefore, home treatment is likely to become the norm; further research will be directed to resolving practical issues.

Review of randomised trials using the post-randomised consent (Zelen's) design

BACKGROUND

In 1979, Zelen described a trial method of randomising participants before acquiring consent in order to enhance recruitment to clinical trials. The method has been criticised ethically due to lack of consent and scientifically due to high crossover rates. This paper reviews recent published trials using this method and describes the reasons authors gave for using the method, examines the crossover rates, and looks at the quality of identified trials.

METHODS

Literature review searching for all citations to the relevant Zelen's papers of trials published since 1990 plus inclusion of trials from personal knowledge.

RESULTS

We identified 58 relevant trials. The most common justification for the use of Zelen method was to avoid the introduction of bias (e.g., to avoid the Hawthorne effect). Few trialists had explicitly used the design to enhance participant recruitment. Most trials (n=41) experienced some crossover from one group to the other (median crossover=8.9%, mean=13.8%, IQR 2.6% to 15%) although this was usually within acceptable limits.

CONCLUSION

The most important reason stated by authors for using Zelen's method was to limit bias. Zelen's method, if carefully used, can avoid 'resentful demoralisation' and the Hawthorne effect biasing a trial. Unlike a previous review, we found that crossover was not a problem for most trials.