Comparison of cost, effectiveness, and safety of injectable anticoagulants used for thromboprophylaxis after orthopedic surgery

Comparison of low-molecular-weight heparins in thromboprophylaxis of major orthopaedic surgery - randomized, prospective pilot study

Aim

To compare the clinical effectiveness of the two most commonly used LMWHs, dalteparin (DALT) and enoxaparin (ENOX), in thromboprophylaxis of elective total hip replacement (THR) or total knee replacement (TKR).

Material and methods

To the prospective, randomized study were included 66 adult patients qualified to undergo THR or TKR (age 63 ± 12 years, 44 women). The patients were randomized to daily in-hospital subcutaneous prophylaxis with 5,000 I.U. of DALT or 40 mg of enoxaparin. Clinical and laboratory data were collected before surgery, and on 1st and 5th days after surgery.

Results

Thirty-four patients were randomized to prophylaxis with ENOX and 32 with DALT. The groups did not differ significantly in age, sex, creatinine and most of the laboratory parameters. The compared groups had similar surgical parameters, but more patients in the ENOX group received red blood cell infusion (17(50%) vs 8(25%); p < 0.05). The Lee–White coagulation time mildly decreased in ENOX and DALT following the surgery (p = ns). There was a shortening of Duke’s bleeding time in DALT after the surgery and it became significantly quicker than that in ENOX on Day 5 (p = 0.03).

Conclusion

The observed difference in Duke’s bleeding time and exceeding blood loss during the surgery on the enoxaparin demands confirmation, as it can be important information for clinical management.

Burden of asthma with elevated blood eosinophil levels

Background

Asthma is a common chronic condition with an economic burden of almost $56 billion annually in the US. Biologic markers like blood eosinophils, that help predict the risk of exacerbation could help guide more optimal treatment plans and reduce cost. The purpose of this study was to determine whether healthcare resource use and expenditures vary by eosinophil level among patients with asthma.

Methods

Patients with a diagnosis of asthma defined by ICD-9-CM code 493.xx between January 2004 and July 2011 were extracted from EMRClaims + database (eMAX Health, White Plains NY). Patients were classified as mild, moderate, or severe by medication use following diagnosis, based on recommendations of National Institutes of Health Expert Panel Report 3. Patients were classified as those with elevated eosinophils (≥400 cells/μL) and normal eosinophil level (<400 cells/μL). Patients were followed for resource use, defined as hospitalizations, ER visits and outpatient visit and associated costs were calculated to assess whether an economic difference exists between eosinophil groups. Non-parametric tests were used to compare resource use and associated cost between elevated and normal eosinophil groups. Multivariate modeling was performed to assess the contribution of eosinophil level on the likelihood of study outcomes among patients with severe asthma.

Results

Among the 2,164 patients meeting eligibility criteria, 1,144 had severity designations. Of these, 179(16 %) of patients had severe asthma of which 20 % (n = 35) had elevated eosinophils. Seventeen percent of patients with elevated eosinophils were admitted to the hospital during the follow-up period, significantly greater than patients with normal eosinophil levels (12 %; p = 0.011). Overall, compared to patients with normal eosinophil levels (n = 1734), patients with elevated eosinophil levels (n = 430) had significantly greater mean annual hospital admissions (0.51 vs. 0.21/year, p = 0.006) and hospital costs (2,536 vs. $1,091, p = 0.011). Logistic regressions showed that elevated eosinophil level was associated with 5.14 times increased odds of all cause admissions (95 % CI:1.76–14.99, p = 0.003) and 4.07 times increased odds of asthma related admissions (95 % CI: 1.26–13.12, p = 0.019).

Conclusion

Eosinophil elevation was associated with greater healthcare resource use in patients with asthma.

Cost-effectiveness of venous thromboembolism prophylaxis with a new mobile device after total hip arthroplasty

Recent comparison (SAFE study) of a mobile, synchronized compression device and low-molecular-weight heparin for prophylaxis of venous thromboembolism showed similar efficacy but significant differences in major bleeding. A model was constructed to evaluate any difference in cost-effectiveness between the 2 therapies incorporating rates and probabilities of major bleeding from the SAFE study with published costs for treating those adverse events. Evaluation of the cost-effectiveness of each therapy was performed and applied to hypothetical patient populations representative of annual health system volume. The model showed a cost-effectiveness advantage of the compression device resulting in a savings of more than $3.69 million in a 10 000-patient cohort. The result was primarily driven by a decrease in the amount of major bleeding, which requires significant health care resources to treat.

Roles of coagulation pathway and factor Xa in the progression of diabetic nephropathy in db/db mice

The active type of coagulation factor X (factor Xa) activates various cell-types through protease-activated receptor 2 (PAR2). We previously reported that a factor Xa inhibitor could suppress Thy-1 nephritis. Considering that fibrin deposition is observed in diabetic nephropathy as well as in glomerulonephritis, this study examined the roles of the coagulation pathway and factor Xa in the development of diabetic nephropathy using type 2 diabetic model mice. Diabetic (db/db) and normoglycemic (m+/m+) mice were immunohistochemically evaluated for their expression/deposition of PAR2, transforming growth factor (TGF)-β, fibrin, extracellular matrix (ECM) proteins, and CD31 at week 20. Significantly greater numbers of PAR2-positive cells and larger amounts of fibronectin, and collagen IV depositions were observed in the glomeruli of db/db mice than those in m+/m+ mice. Next, expression of PAR2 versus deposition of collagen IV and fibronectin was compared between week 20 and week 30, and the number of PAR2-positive cells in the glomeruli decreased in contrast with the increased accumulation of ECM proteins. In an intervention study, fondaparinux, a factor Xa inhibitor, was subcutaneously administered for ten weeks from week 10 to 20. Fondaparinux treatment significantly suppressed urinary protein, glomerular hypertrophy, fibrin deposition, expression of connective tissue growth factor, and ECM proteins deposition together with CD31-positive capillaries. These results suggest that coagulation pathway and glomerular PAR2 expression are upregulated in the early phase of diabetes, together with the increase of profibrotic cytokines expression, ECM proteins deposition and CD-31-positive vessels. Factor Xa inhibition may ameliorate glomerular neoangiogenesis and ECM accumulation in diabetic nephropathy.

Compliance with antithrombotic guidelines in surgery patients in German hospitals: a multicenter study involving pharmacy interns

Despite the existence of antithrombotic guidelines, there is low compliance with these guidelines in clinical practice. Until now pharmacy interns (PIs) have not been involved in this process. The objectives were to involve PIs to evaluate compliance with antithrombotic guidelines for VTE prophylaxis in surgery patients, and in cases of noncompliance to carry out pharmaceutical interventions. The study was conducted in 7 hospitals in Germany involving 27 PIs within the project "Pharmacy interns on the ward" (P-STAT 2). Pharmacy interns determined the thromboembolic risk, documented antithrombotic medication, and checked the compliance with current antithrombotic guidelines. A total of 6491 patients were enrolled; 5695 patients received antithrombotic prophylaxis. Antithrombotic guideline was followed in 77.5% patients. Many patients are not receiving appropriate VTE prophylaxis or heparin bridging regimen despite the fact that evidence-based antithrombotic guidelines are available. Pharmacy interns may play an important role in antithrombotic management.

Extended prophylaxis of venous thromboembolism with fondaparinux in patients undergoing major orthopaedic surgery in Italy: a cost-effectiveness analysis

Enoxaparin is the most frequently used low-molecular weight heparin in the world, given in order to prevent venous thromboembolism (VTE) in patients undergoing major orthopaedic surgery (MOS). Fondaparinux is an effective and safe alternative. The aim of our study was to compare the cost-effectiveness of enoxaparin and fondaparinux in the extended thromboprophylaxis of patients undergoing MOS in Italy. A decision-tree model was developed: probabilities of symptomatic events were derived from the published trials; use of resources in Italy was evaluated by means of a questionnaire administered to a panel of experts. Only the direct costs of VTE (acute treatment of events and of complications) were considered. Cost units were derived from the current cost of drugs, and from the Italian National Healthcare tariffs in 2007. Incremental cost-effectiveness ratios were analysed at three time points: 30 days, 1 year and 5 years. The higher cost of fondaparinux was counterbalanced by reduced rates of early DVT, early PE and prophylaxis-related major bleeding. If compared with enoxaparin, after 30 days of extended prophylaxis, fondaparinux is associated with a savings of <euro> 48.83 per patient; at the end of the first year, the savings increased to <euro> 72.13, and after 5 years, the savings are <euro> 74.36. One-way sensitivity analysis shows that the results are robust to the variation in unit costs for VTE-related care, or in event rates for both treatments. In conclusion, our model shows that, when administered for extended prophylaxis of VTE following MOS, fondaparinux is more effective and cost saving than enoxaparin.

[Orthopedic patients with or without thrombophilia. Diagnostic, therapy and peri-operative strategies]

Venous thrombosis and pulmonary embolisms are currently associated with high mortality rates in Europe as well as in the United States (mortality rate >300,000-500,000/year). The highest risk is attributed to orthopedic surgery. Besides the use of antithrombotic agents, surgical and anesthesiological procedures as well as a multitude of trigger mechanisms, many thrombophilic risk conditions have to be considered. The incidence of thrombotic complications could be continuously reduced by the improvement of different antithrombotic strategies and use of drugs. According to national and international guidelines low molecular weight heparins and fondaparinux (besides aPTT adjusted strategies by using unfractionated heparin) are mainly indicated in high risk patients undergoing hip and knee surgery.The use of newly developed anti-IIa and anti-Xa inhibitors (e.g. dabigatran etexilate, rivaroxaban) is not yet established in guidelines. The discovery of pentasaccharide has further improved the antithrombotic efficiency, but it is still unknown how to manage patients with thrombophilia. Otherwise the knowledge of thrombophilia is not mandatory to know how to manage high risk patients. In contrast information on a history of thrombotic complications as well as indications gained from the family history are of great importance. Whether and to what extent, which patients with or without thrombophilic disposition, under which conditions from which medication within an anti-coagulation prophylaxis profit most over which time period, will be of future interest. Fundamentally, the age of the patient as well as liver and kidney function values and possible interactions between medications must be taken into consideration for selection of individual anti-thrombotic drugs. Even prolongation of medical immobilization prophylaxis can lead to accumulative risks, such as heparin-induced thrombocytopenia, the risk of which grows with increased exposition to the triggering agent.

Economic and clinical evaluation of fondaparinux vs. enoxaparin for thromboprophylaxis following general surgery

PURPOSE

Patients undergoing general surgical procedures are at increased risk for venous thromboembolism (VTE). Compliance rates with established guidelines for VTE thromboprophylaxis in patients at moderate-to-high risk are notably low. Recent literature has demonstrated that fondaparinux is associated with lower costs and fewer VTEs than enoxaparin in patients undergoing major orthopedic surgery (MOS), but data are limited in patients undergoing general surgery. This study was conducted to evaluate the cost implications and relative real-world effectiveness of fondaparinux vs. enoxaparin in general surgery patients.

METHODS

Data were obtained from inpatient billing records from over 500 hospitals using Premier's Perspective Comparative Database. Patients hospitalized for general surgery between July 1, 2003 and January 31, 2006 were eligible for inclusion. Eligible patients were included if they received fondaparinux or enoxaparin after their general surgery date. Patients were excluded if they received both anticoagulants on their first day of therapy, were <18 years of age on the surgery date, or did not have data 6 months prior and 1 month post hospitalization. Included patients were stratified into two cohorts based on their first anticoagulant, fondaparinux or enoxaparin. Patients were matched in each group on 1:1 case-control matching based on propensity scores.

RESULTS

A total of 5364 patients were included (n = 2682 for each cohort) from 326 unique hospitals. Average total costs per patient for the fondaparinux group were significantly lower than the enoxaparin group ($15 156 vs. 17 741, p < 0.0001). Patients receiving fondaparinux were significantly less likely to experience a VTE (2.80 vs. 3.77%, p = 0.046, a 35% relative risk reduction). No significant differences in bleeding events between the cohorts were observed (p = 0.6047), and no significant differences in all-cause inpatient death were noted (p = 0.3673).

CONCLUSION

Fondaparinux was associated with significantly lower costs and fewer VTEs compared to enoxaparin without an increase in bleed rates or all-cause inpatient mortality. The findings from this study are limited by the retrospective study design and should only be generalized to a similar patient population.

Consequences of major bleeding in hospitalized patients with non-ST segment elevation acute coronary syndromes receiving injectable anticoagulants

OBJECTIVE

To evaluate the burden of major bleed in patients with non-ST segment elevation acute coronary syndromes (NSTE ACS) receiving injectable anticoagulation from the hospital perspective.

METHODS

Retrospective analysis of inpatient medical and pharmacy data from the Premier Perspective Comparative Database between 1/1/2003 and 3/31/2006. Hospitalized patients aged >or=18 years with a diagnosis of UA or NSTEMI who received an injectable anticoagulant agent during the same hospital stay were stratified into two cohorts: those who experienced a major bleed during hospitalization and those who did not, defined by the presence of >or=1 pre-specified ICD-9 codes. Length of hospital stay (LOS), inpatient mortality, 30-day readmissions, and hospitalization costs over 30 days were assessed between the cohorts using statistical models to control for covariates which may have impacted the outcomes.

RESULTS

Patients with a major bleed had significantly longer length of stay (13.8 days vs 5.6 days), higher readmission rates (31.3% vs 14.7%), and increased all-cause mortality (15.0% vs 4.5%) compared with patients who did not bleed. After controlling for covariates, major bleeding was significantly associated with increased length of stay, readmission rate, and mortality. Adjusted costs were $13,856 higher on average for patients with a major bleed (95% CI: $13,828-$18,884; p < 0.0001). Subanalyses conducted on patients aged >or=65 years and those undergoing invasive procedures demonstrated higher occurrence of bleed than the general population and a similar impact on outcomes assessed.

CONCLUSION

In conclusion, the study showed that patients with UA or NSTEMI who experience a major bleed have significantly longer hospital stays, higher readmission rates, increased costs, and increased mortality than those without a major bleed. These data emphasize the importance of considering the safety profile in context of the efficacy of the recommended agents. The findings from this study are limited by the retrospective study design and certain endpoints, such as readmissions, may have been underreported.

Current awareness: Pharmacoepidemiology and drug safety

In order to keep subscribers up‐to‐date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of pharmacoepidemiology and drug safety. Each bibliography is divided into 20 sections: 1 Reviews; 2 General; 3 Anti‐infective Agents; 4 Cardiovascular System Agents; 5 CNS Depressive Agents; 6 Non‐steroidal Anti‐inflammatory Agents; 7 CNS Agents; 8 Anti‐neoplastic Agents; 9 Haematological Agents; 10 Neuroregulator‐Blocking Agents; 11 Dermatological Agents; 12 Immunosuppressive Agents; 13 Autonomic Agents; 14 Respiratory System Agents; 15 Neuromuscular Agents; 16 Reproductive System Agents; 17 Gastrointestinal System Agents; 18 Anti‐inflammatory Agents ‐ Steroidal; 19 Teratogens/fetal exposure; 20 Others. Within each section, articles are listed in alphabetical order with respect to author. If, in the preceding period, no publications are located relevant to any one of these headings, that section will be omitted.