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Background The assessment of patients with suspected deep vein thrombosis (DVT) remains challenging despite current diagnostic algorithms. 99m Tc-labelled DI-DD3B6/22-80B3 Fab´ fragments ( 99m Tc-DI-80B3, ThromboView®) is a novel diagnostic test that uses a radiolabelled humanized monoclonal antibody fragment specific for the D-dimer region of cross-linked fibrin to detect DVT. This test has an anatomic component to locate DVT and a functional component to differentiate acute (newly formed) thrombus from inactive (old) thrombus. Methods In a multi-centre prospective cohort trial we investigated the diagnostic accuracy and safety of 99m Tc-DI-80B3 in consecutive patients with suspected DVT who had the diagnosis confirmed or excluded by venography. Results We enrolled 94 patients with suspected DVT of whom 12 did not have 99m Tc-DI-80B3 imaging, leaving 82 patients for the safety analysis. Of these patients, there were 16 with non-evaluable imaging (11 venography, 7 99m Tc-DI-80B3, both in two patients) leaving 66 patients for the accuracy analysis. 99m Tc-DI-80B3 imaging was well-tolerated: 2 patients developed urticaria; none developed serious adverse events. For proximal DVT, the sensitivity (84.2%; 95% confidence interval [CI]: 62.4–94.5) and specificity (97.6%; CI: 83.3–99.4) were highest when the combined 0.25-hour and 3-hour 99m Tc-DI-80B3 images were used. The accuracy was lower for distal DVT, irrespective of the images used. There were insufficient patients to comment on the accuracy of 99m Tc-DI-80B3 imaging for suspected recurrent DVT. Conclusions 99m Tc-DI-80B3 (ThromboView®) is a novel diagnostic modality for patients with suspected DVT with a promising accuracy and safety profile that justifies additional clinical development in diagnostic accuracy and clinical management studies.

The purpose of this study is to probe the current budgeting practices of Canadian advertisers and advertising agencies. Factors related to the sophistication of budgeting methods, changes in the choice of methods, and the influence exerted by advertising agencies are investigated. A comparison of survey results indicates that Canadian advertisers tend to use less sophisticated budgeting approaches than their American counterparts, although similar levels of complexity can be found in their respective practices. A firm's sales volume, size of advertising budget, and market domain do not seem to be related to the sophistication of budgeting practices. The research also shows that Canadian budgeting practices tend to change: While in most cases current method were adopted in the past ten years, dissatisfaction with these methods and intention to change methods appear significant. Resume Cette recherche a pour but d'etudier les methodes budgetaires de compagnies et d'agences de publicite canadennes. Elle analyse le lien existant entre certains facteurs et le degre de sophistication des pratiques en cours, les changements survenant dans le choix des methodes, et l'influence qu'exercent les agences de publicite sur ce choix. Une comparaison de sondages revele que les compagnies canadiennes ont tendance a recourir a des pratiques moins sophistiquees que celles de leurs homologues americains, bien que le niveau de complexite soit comparable. Le volume des ventes, l'importance du budget de publicite, et le domaine d'activites d'une compagnie ne semblent pas lies au degre de sophistication des methodes adoptees. L'etude reele egalement que les methodes canadennes, souvent en vigueur depuis moins de dix ans, sont appelees a changer: on denote en effet chez les repondants un mecontentement et une intention de changement significatifs.

Summary. Background/objectives: We prospectively measured change in quality of life (QOL) during the 2 years after a diagnosis of deep vein thrombosis (DVT) and evaluated determinants of QOL, including development of the post-thrombotic syndrome (PTS). Patients/methods: Consecutive patients with acute DVT were recruited from 2001 to 2004 at eight hospitals in Canada. At study visits at baseline, and 1, 4, 8, 12 and 24 months, clinical data were collected, standardized PTS assessments were performed, and QOL questionnaires were self-completed. Generic QOL was measured using the Short-Form Health Survey-36 (SF-36) questionnaire. Venous disease-specific QOL was measured using the Venous Insufficiency Epidemiological and Economic Study (VEINES)-QOL/Sym questionnaire. The change in QOL scores over a 2-year follow-up was assessed. The influence of PTS and other characteristics on QOL at 2 years was evaluated using multivariable regression analyses. Results: Among the 387 patients recruited, the average age was 56 years, two-thirds were outpatients, and 60% had proximal DVT. The cumulative incidence of PTS was 47%. On average, QOL scores improved during follow-up. However, patients who developed PTS had lower scores at all visits and significantly less improvement in QOL over time (P-values for PTS*time interaction were 0.001, 0.012, 0.014 and 0.006 for PCS, MCS, VEINES-QOL and VEINES-Sym). Multivariable regression analyses showed that PTS (P

Background Venous thromboembolism (VTE) prophylaxis in acutely ill medical patients has been shown to be safe and effective. Underutilization of this patient safety practice may result in avoidable mortality and morbidity. Objectives We aimed to determine the proportion of hospitalized, acutely ill medical patients across Canada who were eligible to receive thromboprophylaxis and to evaluate the frequency, determinants and appropriateness of its use. Patients/Methods CURVE is a national, multicenter chart audit of 29 Canadian hospitals. Data were collected on consecutive patients admitted to hospital for an acute medical illness during a defined 3-week study period. Information on demographic and clinical characteristics, risk factors for VTE and bleeding and use of VTE prophylaxis were recorded. The indications for and appropriateness of VTE prophylaxis were assessed using pre-specified criteria based on international consensus guidelines. Multivariable analyses were performed to identify determinants of prophylaxis use. Results Of the 4124 medical admissions screened over the study period, 1894 patients (46%) were eligible for study inclusion. The most common specified admitting diagnoses were severe infection (28%), COPD exacerbation or respiratory failure (12%), malignancy (9%) and congestive heart failure (8%). Thromboprophylaxis was indicated in 1702 (90%) study patients. Overall, some form of prophylaxis was administered to 23% of all patients. However, only 16% received appropriate thromboprophylaxis. Factors independently associated with greater use of prophylaxis included internist (vs. other specialty) as attending physician (OR 1.33, 95% confidence interval (CI) [1.03, 1.71]), university-associated (vs. community) hospital (OR 1.46, 95% CI [1.03, 2.07]), immobilization (per day) (OR 1.60, 95% CI [1.45, 1.77]), presence of ≥ 1 VTE risk factors (OR = 1.78, 95% CI [1.35, 2.34]) and duration of hospitalization (per day of stay) (OR 1.05, 95% CI [1.03, 1.07]), however, use of prophylaxis was unacceptably low in all groups. Patients with cancer had a significantly reduced likelihood of receiving prophylaxis (OR = 0.40, 95% CI [0.24, 0.68]). Presence of risk factors for bleeding did not influence the use or choice of prophylaxis. Conclusion Most patients hospitalized for medical illness had indications for thromboprophylaxis, yet only 16% received appropriate prophylaxis. Efforts should be made to elucidate the reasons that underlie the very low rate of thromboprophylaxis in medical patients and to develop and test strategies to improve implementation of this patient safety practice.

Summary. Background: The risk of recurrence is lower after treatment of an episode of venous thromboembolism associated with a transient risk factor, such as recent surgery, than after an episode associated with a permanent, or no, risk factor. Retrospective analyses suggest that 1 month of anticoagulation is adequate for patients whose venous thromboembolic event was provoked by a transient risk factor. Methods: In this double-blind study, patients who had completed 1 month of anticoagulant therapy for a first episode of venous thromboembolism provoked by a transient risk factor were randomly assigned to continue warfarin or to placebo for an additional 2 months. Our goal was to determine if the duration of treatment could be reduced without increasing the rate of recurrent venous thromboembolism during 11 months of follow-up. Results: Of 84 patients assigned to placebo, five (6.0%) had recurrent venous thromboembolism, compared with three of 81 (3.7%) assigned to warfarin, resulting in an absolute risk difference of 2.3%[95% confidence interval (CI) − 5.2, 10.0]. The incidence of recurrent venous thromboembolism after discontinuation of warfarin was 6.8% per patient-year in those who received warfarin for 1 month and 3.2% per patient-year in those who received warfarin for 3 months (rate difference of 3.6% per patient-year; 95% CI − 3.8, 11.0). There were no major bleeds in either group. Conclusion: Duration of anticoagulant therapy for venous thromboembolism provoked by a transient risk factor should not be reduced from 3 months to 1 month as this is likely to increase recurrent venous thromboembolism without achieving a clinically important decrease in bleeding.

Background The efficacy and safety of thromboprophylaxis in patients with acute medical illnesses who may be at risk for venous thromboembolism have not been determined in adequately designed trials. Methods In a double-blind study, we randomly assigned 1102 hospitalized patients older than 40 years to receive 40 mg of enoxaparin, 20 mg of enoxaparin, or placebo subcutaneously once daily for 6 to 14 days. Most patients were not in an intensive care unit. The primary outcome was venous thromboembolism between days 1 and 14, defined as deep-vein thrombosis detected by bilateral venography (or duplex ultrasonography) between days 6 and 14 (or earlier if clinically indicated) or documented pulmonary embolism. The duration of follow-up was three months. Results The primary outcome could be assessed in 866 patients. The incidence of venous thromboembolism was significantly lower in the group that received 40 mg of enoxaparin (5.5 percent [16 of 291 patients]) than in the group that received placebo (14.9 percen...

Background Patients who have a first episode of venous thromboembolism in the absence of known risk factors for thrombosis (idiopathic thrombosis) are often treated with anticoagulant therapy for three months. Such patients may benefit from longer treatment, however, because they appear to have an increased risk of recurrence after anticoagulant therapy is stopped. Methods In this double-blind study, we randomly assigned patients who had completed 3 months of anticoagulant therapy for a first episode of idiopathic venous thromboembolism to continue receiving warfarin, with the dose adjusted to achieve an international normalized ratio of 2.0 to 3.0, or to receive placebo for a further 24 months. Our goal was to determine the effects of extended anticoagulant therapy on rates of recurrent symptomatic venous thromboembolism and bleeding. Results A prespecified interim analysis of efficacy led to the early termination of the trial after 162 patients had been enrolled and followed for an average of 10 months....

Purpose: Management of advanced-stage Hodgkin's disease with a MOPP/ABV hybrid regimen (mechlorethamine, vincristine, procarbazine, prednisone, Adriamycin, bleomycin and vinblastine) has yielded a high complete response rate (75–85%). However, myelosuppression can limit delivery of treatment. Filgrastim has been shown to reduce chemotherapy-related neutropenia and allow for on-time administration of planned doses of chemotherapeutic agents. The objective of this study was to find the best way to integrate filgrastim with the MOPP/ABV hybrid regimen. Methods: Enrolled in this study were 24 patients (aged 18–52 years) with newly diagnosed, histologically documented Hodgkin's disease. In schedule I, patients received filgrastim (5 μg/kg s.c. daily) beginning on day 9, 24 h after administration of ABV. In schedule II, patients received filgrastim concomitantly with procarbazine on days 2–7 (starting 24 h after day-1 MOPP administration and stopping 24 h before ABV administration) as well as after ABV beginning on day 9. Filgrastim after ABV administration was administered until two consecutive ANC readings of 10 × 109/l were achieved. Results: All patients were able to complete all six cycles of therapy. There was a trend to fewer dose reductions in schedule II (0.76%) as compared to schedule I (4.2%) with a P-value of 0.077 (chi-squared test). Specifically, 11.6% of MOPP courses and 5.5% of ABV courses were dose-reduced in schedule I versus 1.7% and 1.4%, respectively, in schedule II. Conclusion: In conclusion, filgrastim was effective in supporting the delivery of the MOPP/ABV chemotherapy. Concomitant administration of filgrastim with procarbazine (days 2–7) appears to be safe and allows the maximum dose intensity of this therapy.

This paper describes the results of two studies aimed at comparing four methods of carrying a fiberglass extension ladder. The first study was conducted in the actual work conditions while the other took place in ideal laboratory conditions. Twenty-one telephone technicians participated in the field study while seven participated in the laboratory study together with three subjects having no prior experience with heavy ladder handling. In the field study, the technicians were asked to carry their ladder with each of the four carrying methods. After the completion of each carrying task, the technician rated the method he had just tried on seven subjective measures. Technicians' heart rate was monitored during the complete experiment. In the laboratory study, a similar protocol was used with the difference that the carrying tasks were longer since oxygen uptake was also measured. All telephone technicians had no prior knowledge or practice with three of the carrying methods tested: they had experience only with the carrying method they use in their daily work. Results of the field study show that carrying a fiberglass extension ladder on the shoulder with the arm `Through-the-rungs' imposed the least strain on the cardiovascular system and this method was judged better than or at least equivalent to the carrying method in current use. The results of the laboratory experiment were consistent with those of the field study. The other two methods tested yielded a performance that was inferior to that of the method currently used by telephone technicians in both the field and laboratory studies. The results further show that the study performed in actual work conditions had better validity than the study performed in the laboratory. Relevance to industry Handling of a ladder in varied and adverse environmental conditions is typical in the work of telephone technicians. A better knowledge of safe ladder carrying methods is an important step towards reducing the ladder-handling-related injuries. The results of this study apply to construction workers, electricians, various power utility workers and cable television installers as well.

Background Low-molecular-weight heparin is known to be safe and effective for the initial Treatment of patients with proximal deep-vein thrombosis. However, its application to patients with pulmonary embolism or previous episodes of thromboembolism has not been studied.Methods We randomly assigned 1021 patients with symptomatic venous thromboembolism to fixed-dose, subcutaneous low-molecular-weight heparin (reviparin sodium) or adjusted-dose, intravenous unfractionated heparin. Oral anticoagulant therapy with a coumarin derivative was started concomitantly and continued for 12 weeks, Approximately one third of the patients had associated pulmonary embolism, The outcome events studied over the 12 weeks were symptomatic recurrent venous thromboembolism, major bleeding, and death. We sought to determine whether low-molecular-weight heparin is at least equivalent to unfractionated heparin in patients with venous thromboembolism.Results Twenty-seven of the 510 patients assigned to low-molecular-weight heparin (5.3 percent) had recurrent thromboembolic events, as compared with 25 of the 511 patients assigned to unfractionated heparin (4.9 percent). The difference of 0.4 percentage point indicates that the two therapies have equivalent value according to our predetermined definition of equivalence. Sixteen patients assigned to low-molecular-weight heparin (3.1 percent) and 12 patients assigned to unfractionated heparin (2.3 percent) had episodes of major bleeding (P=0.63), and the mortality rates in the two groups were 7.1 percent and 7.6 percent, respectively (P=0.89).Conclusions Fixed-dose, subcutaneous low-molecular-weight heparin is as effective and safe as adjusted-dose, intravenous unfractionated heparin for the initial management of venous thromboembolism, regardless of whether the patient has pulmonary embolism or a history of venous thromboembolism. (C) 1997, Massachusetts Medical Society.

Four construction workers were tested on a laboratory submaximal cycle ergometer test to establish their heart rate (HR) by oxygen consumption (VO2) relationship. These workers then completed six simulations of a steel access scaffold assembling and disassembling task during which heart rate and oxygen consumption were measured simultaneously with portable monitoring equipment. Two of these subjects had little experience with this work while the others were experts. Two widely used types of scaffold frames were used in the simulation: “5-foot” closed frames and “6-foot” open frames. The mean VO2 measured during work ranged from 1.4 to 1.8 li/min. for a corresponding mean HR ranging from 131 to 155 bpm. There was a significant inverse relationship between relative intensity of HR selected by subjects and performance time. Subjects worked on average at 62% ± 9% of their maximum heart rate range. Models were developed to estimate VO2 from field HR recordings. A certain heat stress had to be taken into account for some of the subjects in the development of these models. VO2 prediction from HR is feasible and can be fairly accurate for scaffold assembling and disassembling work as long as factors which have an impact on HR such as heat stress or incomplete recovery are accounted for.

Summary. Background: The pathophysiology of post-thrombotic syndrome (PTS) is postulated to involve persistent venous obstruction and venous valvular reflux. Objective: To study the association between D-dimer level, valvular reflux and the PTS in a well-defined cohort of deep vein thrombosis (DVT) patients. Methods: Consecutive patients with acute symptomatic DVT were recruited at eight centers and were followed for 24 months. D-dimer was measured at 4 months. A standardized ultrasound assessment for popliteal valvular reflux was performed at 12 months. Using the Villalta scale, patients were assessed for PTS during follow-up by evaluators who were unaware of D-dimer or reflux results. Results: Three hundred and eighty-seven patients were recruited; of these, 305 provided blood samples for D-dimer and 233 had a 12-month reflux assessment. PTS developed in 45.1% of subjects. Mean D-dimer was significantly higher in patients with vs. without PTS (712.0 vs. 444.0 μg L−1; P = 0.02). In logistic regression analyses adjusted for warfarin use at the time of D-dimer determination and risk factors for PTS, D-dimer level significantly predicted PTS (P = 0.03); when stratifying for warfarin use at the time of blood draw, adjusted odds ratio (OR) for developing PTS per unit difference in log D-dimer was 2.33 (95% CI 0.89, 6.10) in those not on warfarin vs. 1.25 (95% CI 0.87, 1.79) in those on warfarin. Ipsilateral reflux was more frequent in patients with moderate-to-severe PTS than in patients with mild PTS (65% vs. 40%, respectively; P = 0.01) and was independently associated with moderate-to-severe PTS in logistic regression analyses (P = 0.01). Conclusion: D-dimer levels, measured 4 months after DVT in patients not on warfarin, are associated with subsequent development of PTS. Venous valvular reflux is associated with moderate-to-severe PTS.

SummaryConsecutive patients undergoing knee arthroplasty or tibial osteotomy at four participating hospitals received either enoxaparin, 30 mg subcutaneously every 12 h (n = 66) or an identicalappearing placebo (n = 65). All study medications started the morning after the operation and were continued up to a maximum of 14 days. Patients underwent surveillance with 125I-fibrinogen leg scanning and impedance plethysmography. Bilateral contrast venography was performed routinely at Day 14 or at time of discharge, if sooner. Deep vein thrombosis was detected by venography in 35 of 54 patients (65%) in the placebo group and in 8 of 41 patients in the enoxaparin group (19%), a risk reduction of 71%, P

Background:Toourknowledge,theburdenofdeepvenous thrombosis from the patient’s perspective has not been quantified. We evaluated health-related quality of life (QOL) after deep vein thrombosis and compared results with general population norms. Methods: This was a multicenter prospective cohort study of 359 consecutive eligible patients with deep vein thrombosisrecruitedat7Canadianhospitalcenters.Quality of life was assessed at baseline and at 1 and 4 months afterdiagnosisusinggeneric(36-ItemShort-FormHealth Survey) and disease-specific (Venous Insufficiency Epidemiological and Economic Study [VEINES]–QOL and VEINES symptom [VEINES-Sym] questionnaires) measures. Changes in QOL scores during the 4-month period were calculated, and determinants of lack of improvement in QOL were evaluated. Results: During the 4 months, mean 36-Item ShortFormHealthSurveyphysicalandmentalcomponentsummary scores improved by 5.1 and 4.6 points, respectively, and VEINES-QOL and VEINES-Sym scores improved by 3.1 and 2.2 points, respectively (P.001 fortimetrendforallmeasures).However,aboutonethird ofpatientshadworseningofQOLduringfollow-up.Multivariate analyses showed that worsening of the postthrombotic syndrome score was an independent predictor of worsening of 36-Item Short-Form Health Survey physical component summary (P=.04), VEINES-QOL (P.001), and VEINES-Sym (P.001) scores. The 36ItemShort-FormHealthSurveyphysicalcomponentsummary scores were lower than population norms at all points assessed. Conclusions: On average, QOL improves during the 4 months following deep vein thrombosis. However, in about one third of patients, QOL deteriorates, and at 4 months, average QOL remains poorer than population norms.Worseningofthepostthromboticsyndromescore is associated with worsening of QOL. Arch Intern Med. 2005;165:1173-1178

Background— When warfarin is interrupted for surgery, low-molecular-weight heparin is often used as bridging therapy. However, this practice has never been evaluated in a large prospective study. This study was designed to assess the efficacy and safety of bridging therapy with low-molecular-weight heparin initiated out of hospital. Methods and Results— This was a prospective, multicenter, single-arm cohort study of patients at high risk of arterial embolism (prosthetic valves and atrial fibrillation with a major risk factor). Warfarin was held for 5 days preoperatively. Low-molecular-weight heparin was given 3 days preoperatively and at least 4 days postoperatively. Patients were followed up for 3 months for thromboembolism and bleeding. Eleven Canadian tertiary care academic centers participated; 224 patients were enrolled. Eight patients (3.6%; 95% CI, 1.8 to 6.9) had an episode of thromboembolism, of which 2 (0.9%; 95% CI, 0.2 to 3.2) were judged to be due to cardioembolism. Of these 8 episodes of thromboembolism, 6 occurred in patients who had warfarin deferred or withdrawn because of bleeding. There were 15 episodes of major bleeding (6.7%; 95% CI, 4.1 to 10.8): 8 occurred intraoperatively or early postoperatively before low-molecular-weight heparin was restarted, 5 occurred in the first postoperative week after low-molecular-weight heparin was restarted, and 2 occurred well after low-molecular-weight heparin was stopped. There were no deaths. Conclusions— Bridging therapy with subcutaneous low-molecular-weight heparin is feasible; however, the optimal approach for the management of patients who require temporary interruption of warfarin to have invasive procedures is uncertain.

Background: There is limited information about risk factors for venous thromboembolism (VTE) in acutely ill hospitalized general medical patients. Methods: An international, randomized, double-masked, placebo-controlled trial (MEDENOX) has previously been conducted in 1102 acutely ill, immobilized general medical patients and has shown the efficacy of using a low-molecular-weight heparin, enoxaparin sodium, in preventing thrombosis. We performed logistic regression analysis to evaluate the independent nature of different types of acute medical illness (heart failure, respiratory failure, infection, rheumatic disorder, and inflammatory bowel disease) and predefined factors (chronic heart and respiratory failure, age, previous VTE, and cancer) as risk factors for VTE. Results: The primary univariate analysis showed that the presence of an acute infectious disease, age older than 75 years, cancer, and a history of VTE were statistically significantly associated with an increased VTE risk. Multiple logistic regression analysis indicated that these factors were independently associated with VTE. Conclusions: Several independent risk factors for VTE were identified. These findings allow recognition of individuals at increased risk of VTE and will contribute to the formulation of an evidence-based risk assessment model for thromboprophylaxis in hospitalized general medical patients.

Context.—Plasma anti-Xa and anti-IIa activities correlate with the dose of low-molecular-weight heparin, and D-dimer and thrombin-antithrombin complexes are markers of procoagulant activity. Objective.—To investigate the relationship between plasma coagulation parameters and patient characteristics, including renal function, thromboprophylaxis, and incidence of venous thromboembolism (VTE) in the MEDENOX study population. Design.—Controlled, multicenter, double-blind, randomized study. Patients.—Two hundred twenty-four acutely ill medical patients. Interventions.—Either 20 or 40 mg of enoxaparin administered subcutaneously or a placebo once daily for 10 (±4) days. Main Outcome Measures.—VTE and plasma anti-Xa and anti-IIa activities, D-dimer, and thrombin-antithrombin levels in blood collected before prophylaxis was given (day 0) and after the last injection of the study drug. Results and Conclusions.—Anti-Xa activity correlated with the dose of enoxaparin. In patients with mild or moderate renal impairment, there was no significant relationship between anti-Xa activity and the creatinine clearance rate. D-dimer concentrations were lower at day 10 (±4) in the 40-mg group, which had a 63% lower VTE incidence, than at day 0. No venographically confirmed thromboses were found in patients with a normal D-dimer concentration (

Objective : To compare the effectiveness and safety of fixed-dose enoxaparin and adjusted-dose warfarin in preventing venous thromboembolism after knee arthroplasty. Design : A randomized, double-blind controlled trial. Setting : 8 university hospitals. Patients : 670 consecutive patients who had knee arthroplasty. Intervention : Patients were randomly assigned to receive enoxaparin (30 mg subcutaneously every 12 hours) or adjusted-dose warfarin (international normalized ratio, 2.0 to 3.0). Both regimens were started after surgery. Measurements : The primary end point was the incidence of deep venous thrombosis in patients with adequate bilateral venograms ; the secondary end point was hemorrhage. Results : Among the 417 patients with adequate venograms, 109 of 211 warfarin recipients (51.7%) had deep venous thrombosis compared with 76 of 206 enoxaparin recipients (36.9%) (P = 0.003). The absolute risk difference was 14.8% in favor of enoxaparin (95% CI, 5.3% to 24.1%). Twenty-two warfarin recipients (10.4%) and 24 enoxaparin recipients (11.7%) had proximal venous thrombosis (P > 0.2). The absolute risk difference was 1.2% in favor of warfarin (Cl, -7.2% to 4.8%). The incidence of major bleeding was 1.8% (6 of 334 patients) in the warfarin group and 2.1% (7 of 336 patients) in the enoxaparin group (P > 0.2). The absolute risk difference was 0.3% in favor of warfarin (Cl, -2.4% to 1.8%). Conclusions : A postoperative, fixed-dose enoxaparin regimen is more effective than adjusted-dose warfarin in preventing total deep venous thrombosis after knee arthroplasty. No differences were seen in the incidence of proximal venous thrombosis or clinically overt hemorrhage.

Patients with acute proximal deep-vein thrombosis are usually treated first in the hospital with intravenous standard (unfractionated) heparin. However, the longer plasma half-life, better bioavailability after subcutaneous administration, and more predictable anticoagulant response of low-molecular-weight heparins make them attractive for possible home use. We compared these two approaches.Patients with acute proximal deep-vein thrombosis were randomly assigned to receive either intravenous standard heparin in the hospital (253 patients) or low-molecular-weight heparin (1 mg of enoxaparin per kilogram of body weight subcutaneously twice daily) administered primarily at home (247 patients). The study design allowed outpatients taking low-molecular-weight heparin to go home immediately and hospitalized patients taking low-molecular-weight heparin to be discharged early. All the patients received warfarin starting on the second day.Thirteen of the 247 patients receiving low-molecular-weight heparin (5.3 percent) had recurrent thromboembolism, as compared with 17 of the 253 patients receiving standard heparin (6.7 percent; P=0.57; absolute difference, 1.4 percentage points; 95 percent confidence interval, -3.0 to 5.7). Five patients receiving low-molecular-weight heparin had major bleeding, as compared with three patients receiving standard heparin. After randomization, the patients who received low-molecular-weight heparin spent a mean of 1.1 days in the hospital, as compared with 6.5 days for the standard-heparin group; 120 patients in the low-molecular-weight- heparin group did not need to be hospitalized at all.Low-molecular-weight heparin can be used safely and effectively to treat patients with proximal deep-vein thrombosis at home.

Abstract 566 Background and objectives: Deep venous thrombosis (DVT) is a common and serious vascular condition that is frequently complicated by the chronic post-thrombotic syndrome. Costs of DVT may occur over a long period and may be medical and non-medical in nature. During a Canadian multicenter cohort study of the long-term outcomes after DVT (The Venous Thrombosis Outcomes [VETO] Study), we prospectively quantified resource use and costs related to DVT during two years after DVT diagnosis, and identified clinical determinants of costs. Methods: The study population consisted of 355 consecutive patients diagnosed with objectively confirmed acute DVT at one of 7 participating hospitals in the province of Quebec, Canada. Using a societal perspective, we tracked total medical resource use (hospitalizations, physician visits, other health professional visits, medications, ambulance services, stockings, assistive devices) and non-medical resource use (loss of productivity, home care, transportation) incurred by DVT during the 2 years after diagnosis. Data sources included weekly patient-completed cost diaries, nurse-completed case report forms (baseline, 1, 4, 8, 12, 24 months and at any DVT-related clinical event) and the Quebec provincial administrative healthcare database (“RAMQ”). Resources for each patient were valued using individual patient level information obtained from RAMQ and patient diaries. Statistics Canada data, provincial health professionals associations and local suppliers were used to estimate resource costs if individual information was not available. The value of lost productivity was estimated using a friction-cost approach. Multivariate regression modeling for predictors of medical costs during 2 years included baseline demographic and clinical characteristics as well as the development of post-thrombotic syndrome (PTS) during study follow-up. Results: At study entry, mean age was 56.5 years, 50.1% were male, 2/3 were out-patients and 58.0% had proximal DVT. The mean duration of heparin and warfarin treatment was 7.6 days (SD 6.0) and 21.6 weeks (SD 10.0), respectively. During 2 years follow-up, the rate of DVT-related hospitalization was 3.5 per 100 patient-years (95% CI 2.2, 4.9). Patients reported, on average, 15.0 (SD 14.5) physician visits and 0.7 (SD 1.2) non-physician visits. Patients required 12.7 (SD 9.2) transportations, 38.6 (SD 138.0) hours of assistance and missed 12.1 (SD 39.8) workdays. The average per-patient total cost over 2 years was Can$4109 (95% CI $3658, $4561) with 63.7% of costs attributable to non-medical resource use. The two largest medical cost components were hospitalizations (Can$502; 95% CI $261, $744) and physician visits (Can$356; 95% CI $320, $392). More than two-thirds of all resource consumption occurred during the first 4 months after diagnosis. In multivariate analysis focusing on determinants of medical costs, concomitant pulmonary embolism (p = 0.002), idiopathic DVT (p= 0.003), and development of post-thrombotic syndrome during follow-up (p= 0.002) were independently associated with increased costs. Conclusion: The economic burden of DVT over the two years following initial diagnosis is substantial with almost two-thirds of costs attributable to non-medical resource use. Concomitant pulmonary embolism, idiopathic DVT, and development of PTS are important predictors of medical costs after DVT. Better adherence to thromboprophylaxis strategies and use of measures to prevent occurrence of PTS have the potential to diminish costs and resource utilization related to DVT. Disclosures: No relevant conflicts of interest to declare.

The reason some patients with deep venous thrombosis (DVT) develop the postthrombotic syndrome is not well understood.To determine the frequency, time course, and predictors of the postthrombotic syndrome after acute DVT.Prospective, multicenter cohort study.8 Canadian hospital centers.387 outpatients and inpatients who received an objective diagnosis of acute symptomatic DVT were recruited from 2001 to 2004.Standardized assessments for the postthrombotic syndrome using the Villalta scale at 1, 4, 8, 12, and 24 months after enrollment. Mean postthrombotic score and severity category at each interval was calculated. Predictors of postthrombotic score profiles over time since diagnosis of DVT were identified by using linear mixed modeling.At all study intervals, about 30% of patients had mild (score, 5 to 9), 10% had moderate (score, 10 to 14), and 3% had severe (score14 or ulcer) postthrombotic syndrome. Greater postthrombotic severity category at the 1-month visit strongly predicted higher mean postthrombotic scores throughout 24 months of follow-up (1.97, 5.03, and 7.00 increase in Villalta score for mild, moderate, and severe 1-month severity categories, respectively, vs. none; P0.001). Additional predictors of higher scores over time were venous thrombosis of the common femoral or iliac vein (2.23 increase in score vs. distal [calf] venous thrombosis; P0.001), higher body mass index (0.14 increase in score per kg/m(2); P0.001), previous ipsilateral venous thrombosis (1.78 increase in score; P = 0.001), older age (0.30 increase in score per 10-year age increase; P = 0.011), and female sex (0.79 increase in score; P = 0.020).Decisions to prescribe compression stockings were left to treating physicians rather than by protocol. Because international normalized ratio data were unavailable, the relationship between anticoagulation quality and Villalta scores could not be assessed.The postthrombotic syndrome occurs frequently after DVT. Patients with extensive DVT and those with more severe postthrombotic manifestations 1 month after DVT have poorer long-term outcomes.

OBJECTIVE: To assess the validity of VEINES-QOL/Sym, a patient-reported questionnaire to evaluate quality of life and symptoms in patients with deep venous thrombosis (DVT). STUDY DESIGN AND SETTING: Psychometric study within the Venous Thrombosis Outcomes (VETO) Study, a prospective cohort study of long-term outcomes after DVT. A total of 359 English- and French-speaking patients with acute, objectively diagnosed DVT were recruited at seven hospitals in Quebec, Canada. The VEINES-QOL/Sym questionnaire, a 26-item patient-reported measure that generates separate summary scores for symptoms (VEINES-Sym) and quality of life (VEINES-QOL) was evaluated for acceptability, reliability, validity, and responsiveness in VETO Study subjects. RESULTS: Standard psychometric tests confirmed the acceptability (missing data, item endorsement frequencies, floor and ceiling effects), reliability (internal consistency, item-total and inter-item correlations, test-retest), validity (content, construct, convergent, discriminant, known groups), and responsiveness to clinical change of the VEINES-QOL/Sym in patients with DVT. CONCLUSION: The VEINES-QOL/Sym is a practical and scientifically sound patient-reported measure of outcomes that was developed using gold-standard methods. VEINES-QOL/Sym is valid and reliable for use as a measure of quality of life and symptoms in patients with acute DVT and provides a rigorous tool to allow more comprehensive evaluation of outcomes in clinical trials and epidemiological studies of patients with DVT.

Background and Objectives: It is not understood why some patients develop post thrombotic syndrome (PTS) after DVT while others recover without sequelae. We performed a prospective, multicenter study of long-term outcomes after DVT (the Venous Thrombosis Outcomes [VETO] Study) whose principal aim was to identify predictors of PTS. Methods: From 2001–2002, consecutive patients with objectively diagnosed DVT were recruited at 7 hospital centres. During study visits at Baseline, 1, 4, 8, 12 and 24 months, clinical data were collected, thrombophilia testing was performed and standardized assessments for PTS (using Villalta scale) were carried out by trained personnel. Patients were classified as having developed PTS if the ipsilateral Villalta score was ≥5 on at least 2 visits or at the final follow-up visit, and severe PTS if a score of >14 or a venous ulcer was documented on any one occasion. The influence of clinical, demographic, ergonomic and biological determinants on the risk of developing PTS was evaluated in bivariate and multivariate analyses. Results: 359 patients were recruited; 49% were male, mean age was 56 years, 2/3 were outpatients and 55% had proximal DVT. The cumulative risk of PTS was 37%, of which 1 in 6 cases was severe. Patients who developed PTS, compared with those who did not, were more likely to be older (p=.005), have had previous episode(s) of DVT (p=.0003), have atherosclerosis risk factors [hypertension (p=.0002), high cholesterol (p=.02)], higher BMI (p=0.0007), longer duration of symptoms before DVT diagnosis (p=.049) and work in a job with high physical demands (p=.05), and they were less likely to have the Prothrombin gene mutation (p=0.03). Variables of interest that did not influence the risk of PTS included: sex, location of DVT (proximal vs. distal), side of DVT (left vs. right), type of DVT (cancer-related, temporary risk factors [e.g. surgery, trauma] or idiopathic), initial anticoagulation with LMWH vs. UFH, duration of warfarin, Factor V Leiden mutation or prior ipsilateral musculoskeletal condition. In adjusted multivariate analyses, BMI (odds ratio [OR] 2.1 for BMI >30 vs. < 30, 95% confidence interval [CI] 1.1, 4.2), previous DVT (OR 2.6, 95% CI 1.4, 4.9) and hypertension (OR 1.9, 95% CI 1.04, 3.6) were independently associated with PTS. Conclusions: In our cohort, high BMI, previous history of DVT and hypertension were independent predictors of PTS, whereas presenting characteristics of the index DVT and its treatment did not influence the risk of developing PTS.

Background and Objectives: The post thrombotic syndrome (PTS) is a chronic complication of deep venous thrombosis (DVT). It is difficult to provide DVT patients with long-term prognostic information as there is little longitudinal data on the occurrence of PTS after DVT. We performed a prospective multicenter study of long-term outcomes after DVT (the Venous Thrombosis Outcomes [VETO] Study) to determine the incidence, timing of onset and severity of PTS. Methods: Consecutive patients with objectively diagnosed acute DVT were recruited at 7 participating hospital centres from April 2001-July 2002. Patients attended study visits at Baseline, 4, 8, 12 and 24 months. Clinical data were recorded and standardized assessments for PTS (using Villalta scale) were performed by trained study personnel at each follow-up visit. Patients were classified as having developed PTS if the ipsilateral Villalta score was ≥ 5 on at least 2 visits or at the final follow-up visit, and having severe PTS if a score of >14 or a venous ulcer was documented on any one occasion. The Kaplan-Meier survival method was used to estimate the cumulative probability of PTS and of severe PTS over time. Results: The study cohort consisted of 359 patients. The mean age was 56 years, 50% were male, 2/3 were outpatients, 55% had proximal DVT and 20% had previous DVT. The Kaplan-Meier estimates of cumulative risk of PTS were 29% at 4 months, 33% at 8 months, 35% at 12 months and 37% at 24 months. Corresponding risks of severe PTS were 6.6%, 6.9%, 6.9% and 6.9%, respectively. When the analysis was stratified according to history of DVT, the cumulative incidence of PTS in patients without previous DVT was 25%, 28%, 30% and 31% at 4, 8, 12 and 24 months. Corresponding rates of PTS in patients with previous DVT were 45%, 51%, 53% and 57%. Conclusions: More than one third of patients in our cohort developed PTS within 2 years of DVT, and of these, 1 in 6 was classified as severe. Most cases of PTS and of severe PTS were apparent by 4 months after DVT. Patients with previous DVT had a higher frequency of PTS and of late onset PTS. Our study provides longitudinal data on prognosis that is relevant both to patients with DVT and their treating physicians.

Objectives: To assess the validity and reliability of VEINES-QOL/Sym, a patient-reported questionnaire, for the evaluation of quality of life and symptoms in patients with deep venous thrombosis. Study design: Psychometric study within the Venous Thrombosis Outcomes (VETO) Study, a Canadian multicenter prospective cohort study of long term outcomes after venous thrombosis. Subjects: 359 English and French-speaking patients with deep vein thrombosis consecutively recruited at seven hospitals in the province of Quebec, Canada. Outcome measures: The 26-item VEINES-QOL/Sym is a patient-reported questionnaire that we originally developed and validated for use in patients with chronic venous disorders of the leg (J Vasc Surg 2003). VEINES-QOL/Sym generates separate summary scores for symptoms and quality of life. We performed a comprehensive psychometric evaluation of the acceptability, reliability, validity and responsiveness of VEINES-QOL/Sym in the VETO study population, all of whom had objectively diagnosed symptomatic deep venous thrombosis (mean age 56 years; 50% male; 67% outpatients; 55% proximal DVT). Results: Criterion-standard psychometric tests confirmed the acceptability (missing data, item endorsement frequencies, floor and ceiling effects), reliability (internal consistency, item-total and inter-item correlations, test-retest), validity (content, construct, convergent, discriminant, known groups) and responsiveness to clinical change of the VEINES-QOL/Sym. Conclusions: Our results indicate that VEINES-QOL/Sym is a practical, valid and reliable measure of quality of life and symptoms in patients with deep venous thrombosis. VEINES-QOL/Sym provides a rigorous tool to allow more comprehensive evaluation of patient outcomes in clinical trials and epidemiological studies of patients with deep venous thrombosis.

To the Editor. —The desirability of universal immunization of young adolescents against hepatitis B virus (HBV) has recently been reemphasized by the National Coalition for Adult Immunization and the Centers for Disease Control and Prevention. 1 On occasion, HBV serology is available in an unvaccinated child scheduled for immunization. If only 1 of the HBV antibodies is positive, a decision has to be made whether this is likely to be a false-positive result. In Quebec City, approximately 7000 fourth-grade children are immunized each year in the provincial program of universal immunization. In 1995, we conducted a prevaccination seroprevalence survey in these children. All children were eligible. Parents were called sequentially to participate in the study as soon as the consent form they had to sign to have their child immunized in the provincial program was received. The required sample size of 1200 was reached after calling 2014 parents. Among those

This paper summarizes a group of studies regarding Millerand harbor, located on the Îles-de-la-Madeleine coast, which blocks most of the local littoral drift. The understanding and quantification of this sedimentological problem was first carried out using numerical models. Various schemes were then tested in two mobile-bed physical models. Finally, the impact of these solutions on the wave climate in the harbor and in the entrance channel was compared using a diffraction–reflection numerical model. The results show that accretion in Millerand harbor will only be controlled by the construction of a breakwater. This breakwater must close the east side of the harbor and must reach at least 2 m depth at its toe. It is also strongly recommended that two groins be built on the east-side beach to control the erosion of the cliff. The results of the diffraction–reflection model finally give some latitude to the harbor planners, as several schemes present satisfactory wave agitation maps. Key words: erosion, accretion, breakwater, diffraction–reflection, harbor, littoral drift, numerical model, physical model, wave hindcasting.

Background and Objectives: The long term effects of deep venous thrombosis (DVT) on health-related quality of life (QOL) have not been prospectively evaluated. During a Canadian multicentre cohort study of health and economic outcomes after DVT (the Venous Thrombosis Outcomes [VETO] Study), we measured QOL during the 2 years after DVT and evaluated the influence of development of post-thrombotic syndrome (PTS) and other determinants on QOL. Methods: Consecutive patients diagnosed with acute DVT at seven participating hospital centres were recruited from April 2001-July 2002. During study visits at Baseline, 1, 4, 8, 12 and 24 months, clinical data were collected, a standardized assessment for PTS was performed and QOL questionnaires were self-completed. Generic QOL was measured using the SF-36 Health Survey questionnaire. Venous disease-specific QOL was measured using the VEINES-QOL questionnaire. For both questionnaires, lower scores indicate poorer QOL. Mean QOL at each time point and change in QOL scores over 24 months follow-up were quantified. The influence of PTS and other clinical or demographic characteristics on QOL was evaluated using multivariate regression analyses. Results: Of the 359 patients recruited, 49% were male, average age was 56 years, 2/3 were outpatients and 55% had proximal DVT. The cumulative incidence of PTS during follow-up was 37%. On average, QOL scores in the cohort improved during follow-up (mean improvement from Baseline to 24 months: 7.2 points for SF-36 mental component summary (MCS), 7.5 points for SF-36 physical component summary (PCS) and 4.7 points for VEINES-QOL). Patients who developed PTS, compared with those who did not, had significantly lower PCS scores and VEINES-QOL scores at all 5 follow-up visits (differences for PTS vs. no PTS ranged from 2.4-9.0 points for PCS and from 4.5-6.0 points for VEINES-QOL), and significantly lower MCS scores at the 1, 4, 8 and 12 month visits (differences ranged from 3.7–4.7 points). Multivariate regression analyses adjusted for age, sex and comorbidity showed that PTS and proximal (vs. distal) location of initial DVT were strong independent predictors of lack of improvement of PCS scores (p=.003 and .02, respectively) and VEINES-QOL scores (p=.006 and .009, respectively) during follow-up, but not of MCS scores (p=0.054 and 0.86, respectively). Variables such as body mass index, concurrent pulmonary embolism at time of DVT diagnosis and previous history of DVT did not influence change in scores for any QOL measure. Conclusions: The principal determinants of quality of life after DVT are development of PTS and proximal (vs. distal) location of initial DVT. Our study provides valuable prognostic information on health outcomes after DVT.