Low-molecular-weight heparin prophylaxis of deep vein thrombosis for older patients with restricted mobility: propensity analyses of data from two multicentre, cross-sectional studies.

BACKGROUND: Although older patients with restricted mobility are at increased risk for venous thromboembolism, they are under-represented in clinical trials evaluating prophylactic treatments against deep vein thrombosis (DVT). OBJECTIVE: To determine whether prolonged prophylaxis with low-molecular-weight heparin (LMWH) is associated with a lower rate of DVT in older patients with restricted mobility. METHODS: Two cross-sectional studies were conducted in 50 hospital-based, post-acute care facilities in France in 2001 and 2003. The studies included 1603 evaluable patients aged >or=65 years, including 866 LMWH users (median treatment duration 23 days; interquartile range 13-42) and 737 LMWH non-users. All patients underwent complete compression ultrasonography performed by board-certified vascular medicine physicians. The primary study outcome was proximal DVT. Propensity analyses were used to control for bias in LMWH treatment assignment. RESULTS: The rate of proximal DVT was 4% (35/866) and 5.7% (42/737) for LMWH users and non-users, respectively (p = 0.16). Prophylaxis with LMWH was associated with decreased odds of proximal DVT after adjusting for baseline characteristics (odds ratio [OR] 0.56; 95% CI 0.33, 0.95; p = 0.03) or quintile of propensity score (OR 0.58; 95% CI 0.35, 0.99; p = 0.04). In propensity matched analysis, 342 LMWH users were at decreased odds of proximal DVT compared with 342 non-users (OR 0.50; 95% CI 0.24, 1.00; p = 0.04). The decrease in proximal DVT was paralleled by a similar decrease in distal DVT. Compared with non-users, only high-risk dose users had decreased odds of DVT. CONCLUSIONS: In this observational study, prophylaxis with a high-risk dose of LMWH was associated with decreased odds of proximal DVT in older patients with restricted mobility. Further study is needed before recommending routine prophylaxis with LMWH in these patients.

A clinical prediction score for upper extremity deep venous thrombosis.

It was the objective of this study to design a clinical prediction score for the diagnosis of upper extremity deep venous thrombosis (UEDVT). A score was built by multivariate logistic regression in a sample of patients hospitalized for suspicion of UEDVT (derivation sample). It was validated in a second sample in the same university hospital, then in a sample from the multicenter OPTIMEV study that included both outpatients and inpatients. In these three samples, UEDVT diagnosis was objectively confirmed by ultrasound. The derivation sample included 140 patients among whom 50 had confirmed UEDVT, the validation sample included 103 patients among whom 46 had UEDVT, and the OPTIMEV sample included 214 patients among whom 65 had UEDVT. The clinical score identified a combination of four items (venous material, localized pain, unilateral pitting edema and other diagnosis as plausible). One point was attributed to each item (positive for the first 3 and negative for the other diagnosis). A score of -1 or 0 characterized low probability patients, a score of 1 identified intermediate probability patients, and a score of 2 or 3 identified patients with high probability. Low probability score identified a prevalence of UEDVT of 12, 9 and 13%, respectively, in the derivation, validation and OPTIMEV samples. High probability score identified a prevalence of UEDVT of 70, 64 and 69% respectively. In conclusion we propose a simple score to calculate clinical probability of UEDVT. This score might be a useful test in clinical trials as well as in clinical practice.

Effectiveness of a guideline for venous thromboembolism prophylaxis in elderly post-acute care patients: a multicenter study with systematic ultrasonographic examination.

BACKGROUND: Thromboprophylaxis in elderly patients, including post-acute care patients, is at variance with scientific evidence. The purpose of this study was to determine whether a multifaceted intervention was followed by a decrease in deep venous thrombosis (DVT). METHODS: A prospective preintervention-postintervention study was conducted in 1373 patients (preintervention phase, n = 709; postintervention phase, n = 664), aged 65 years or older, enrolled in 33 hospital-based post-acute care facilities in France. An evidence-based guideline addressing pharmacologic and mechanical prophylaxis was implemented through a multifaceted intervention. The main outcome measure was any DVT diagnosed at routine comprehensive ultrasonography performed by registered angiologists. RESULTS: A DVT was found in 91 patients (12.8%) in the preintervention phase and in 52 patients (7.8%) in the postintervention phase (P = .002). The decrease in DVT involved the calf (7.1% vs 3.6%; P = .005) and the proximal venous segments (5.8% vs 4.2%; P = .18) and remained significant after adjusting for risk factors (adjusted odds ratio of any DVT, 0.58; 95% confidence interval, 0.39-0.86). Pharmacologic prophylaxis with either low-molecular-weight heparin at the high-risk dose, unfractionated heparin, and vitamin K antagonist was similar in the 2 study groups, whereas patients in the postintervention group were more likely to use graduated compression stockings (27.4% vs 34.6%; P = .004) and less likely to receive low-molecular-weight heparin at the low-risk dose (24.7% vs 18.5%; P = .006), which was not recommended by our guideline. CONCLUSIONS: A multifaceted intervention addressing venous thromboembolism prophylaxis in post-acute care patients can be followed by a significant decrease in the rate of any DVT in elderly patients. More active interventions are needed to enforce compliance with evidence-based guidelines.

Deep vein thrombosis in elderly patients hospitalized in subacute care facilities: a multicenter cross-sectional study of risk factors, prophylaxis, and prevalence.

BACKGROUND: The efficacy of venous thromboembolism prophylaxis has not been established, to our knowledge, in elderly patients hospitalized in subacute care facilities. OBJECTIVES: To describe risk factors and physician practices in the prevention of venous thromboembolism and to estimate the prevalence of deep vein thrombosis. METHODS: A multicenter cross-sectional study was conducted in the subacute care departments of 36 French hospitals. The study population included 852 inpatients older than 64 years. Systematic ultrasound examination was performed by angiologists. RESULTS: Of the 852 inpatients, 178 (20.9%; 95% confidence interval [CI], 18.2%-23.8%) had 3 or more risk factors other than age, while 144 patients (16.9%; 95% CI, 14.4%-19.6%) had none. The rate of prophylactic anticoagulant treatment was 56.1%, ranging from 20.0% to 86.9%, depending on the department. In multivariate analysis, prophylaxis use was associated with acute immobilization (odds ratio [OR], 4.17; 95% CI, 2.48-7.01), chronic immobilization (OR, 3.19; 95% CI, 2.22-4.60), major surgical procedure (OR, 6.81; 95% CI, 4.26-10.88), and congestive heart failure (OR, 1.65; 95% CI, 1.02-2.67). Prophylaxis use was low in patients who had cancer (OR, 0.49; 95% CI, 0.29-0.84) or myocardial infarction (OR, 0.39; 95% CI, 0.14-1.00). It was not significantly associated with paralytic stroke or history of venous thromboembolism. Deep vein thrombosis was detected in 135 patients (15.8%; 95% CI, 13.4%-18.5%): 50 (5.9%; 95% CI, 4.4%-7.7%) had proximal vein thrombosis and 85 (10.0%; 95% CI, 8.0%-12.2%) had calf vein thrombosis. CONCLUSIONS: The prevalence of deep venous thrombosis is high in these patients, despite wide use of prophylaxis. Further prospective studies assessing the clinical benefit of extended duration prophylaxis are needed in elderly patients hospitalized in subacute care settings.