Post-discharge patient-reported non-adherence to aspirin compared to enoxaparin for venous thromboembolism prophylaxis after hip or knee arthroplasty

BACKGROUND

Aspirin and enoxaparin are commonly used for venous thromboembolism (VTE) prophylaxis following total hip arthroplasty (THA) or total knee arthroplasty (TKA). The purpose of this study was to compare non-adherence after discharge to aspirin or enoxaparin following THA or TKA.

METHODS

A subset of participants in the CRISTAL study were selected for participation. Additional inclusion criteria were no preoperative anticoagulant use and discharge from hospital before the prophylaxis period ended. The first four consecutive patients from each arm at each participating hospital were planned to be recruited (planned sample size n = 248). A patient-reported adherence questionnaire was completed by telephone at 36-41 days after THA and at 15-20 days after TKA. The primary outcome was non-adherence. Secondary outcomes were number of missed doses and the reasons for non-adherence.

RESULTS

There were 178 participants included from 15 sites, less than planned explained by early stopping of trial recruitment. There was no significant between-group difference in patient-reported non-adherence: 24% (17/71) for aspirin, 30% (32/107) for enoxaparin, odds ratio = 1.4 (95% CI 0.7-2.9). The mean number of missed doses was 2.5 for aspirin and 3.4 for enoxaparin (mean difference = 0.9 doses, 95% CI -1.2 to 3.1). For aspirin, the most commonly reported reason for non-adherence was forgotten doses and for enoxaparin it was clinician-recommended change.

CONCLUSIONS

Rates of non-adherence and the number of missing doses were similar for patients regardless of drug prescribed. The most common reasons for non-adherence were unrelated to the mode of administration.

A Prospective Randomized Controlled Trial Comparing Enoxaparin & Rivaroxaban for Venous Thromboembolism Prophylaxis in Orthopaedic Trauma

OBJECTIVES

To determine whether there is a difference in orthopaedic trauma patient medication satisfaction and adherence using an oral versus subcutaneous injectable anticoagulant for venous thromboembolism chemoprophylaxis.

DESIGN

Randomized controlled trial.

SETTING

Single academic Level 1 trauma center.

PARTICIPANTS

One hundred twenty adult orthopaedic trauma patients with operative pelvic or lower extremity fractures were randomized and completed the study.

INTERVENTION

Three weeks of either the service standard 40 mg once daily enoxaparin versus trial medication 10 mg once daily rivaroxaban postoperatively.

MAIN OUTCOME MEASURES

Patient satisfaction as measured by the Treatment Satisfaction Questionnaire for Medication (TSQM-9). Medication adherence as measured by the Morisky Medication Adherence Scale (MMAS-8).

RESULTS

Medication adherence was similar in both groups. Medication satisfaction was significantly higher in the oral rivaroxaban group based on the TSQM-9 and patient-reported data. Secondary outcomes found no significant difference in the incidence of bleeding events or clinically relevant venous thromboembolism. The enoxaparin group experienced more adverse medication-related events. The rivaroxaban medication regimen costs 7.5-10× less out of pocket for uninsured patients.

CONCLUSION

The results of this randomized controlled trial demonstrate that patients with surgical orthopaedic trauma prefer an oral anticoagulant for postoperative venous thromboembolism chemoprophylaxis and suggest that rivaroxaban may be a viable option. Furthermore, large-scale studies are needed to confirm safety and efficacy for rivaroxaban in this population as a potential alternative to enoxaparin and aspirin.

LEVEL OF EVIDENCE

Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Incorporating Patient Preferences into a Decision-Making Model of Hand Trauma Reconstruction

Background: Few studies have addressed patient preferences in emergent surgical decision making. Aim of the study: Analyzing patient preferences for hand trauma reconstruction to propose a decision-making model. Methods: A conjoint analysis survey was developed with Sawtooth Software. Three common flaps—i.e., a cross-finger flap (CFF), a dorsal metacarpal artery perforator flap (DMAPF), and an arterialized venous flap (AVF)—were listed as treatment alternatives. Five attributes corresponding to these flaps were recovery time, total procedure, postoperative care methods, postoperative scar condition, and complication rate. Utility and importance scores were generated from the software, and preference characteristics were evaluated using cluster analysis. Results: The survey was completed by 197 participants with hand trauma. Complication risk received the highest importance score (42.87%), followed by scar condition (21.55%). Cluster analysis classified the participants as “conservative,” “practical,” and “dual-concern”. The dual-concern and conservative groups had more foreign laborers and highly educated participants, respectively, than the other groups. Most participants in the conservative and practical groups preferred DMAPF, whereas those in the dual-concern group favored CFF. Our proposed model consisted of shared decision-making and treatment recommendation pathways. Conclusion: Incorporating patient preferences into the decision-making model can strengthen patient-centered care. Further research on the applications of the proposed model is warranted.

Health state utilities associated with treatment process for oral and injectable GLP-1 receptor agonists for type 2 diabetes

Purpose

Previous research suggests that treatment process can have an influence on patient preference and health state utilities. This study examined preferences and estimated utilities for treatment processes of two daily oral treatment regimens and two weekly injectable regimens for treatment of type 2 diabetes (T2D).

Methods

Participants with T2D in the UK reported preferences and valued four health state vignettes in time trade-off utility interviews. The vignettes had identical descriptions of T2D but differed in treatment process: (1) daily simple oral treatment (tablets without administration requirements), (2) daily oral semaglutide (with administration requirements per product label), (3) weekly dulaglutide injection, (4) weekly semaglutide injection.

Results

Interviews were completed by 201 participants (52.7% male; mean age = 58.7). Preferences between treatment processes varied widely. Mean utilities were 0.890 for simple oral, 0.880 for oral semaglutide, 0.878 for dulaglutide injection, and 0.859 for semaglutide injection (with higher scores indicating greater preference). All pairwise comparisons found statistically significant differences between utilities (p < 0.01), except the comparison between oral semaglutide and the dulaglutide injection (p = 0.49).

Conclusions

Results suggest that routes of administration cannot be compared using only the simplest descriptions (e.g., oral versus injectable). Dose frequency and specific details of the treatment process administration had an impact on patient preference and health state utilities. The utilities estimated in this study may be useful in cost-utility models comparing these treatments for T2D. Results also suggest that it may be helpful to consider patient preferences for treatment process when selecting medications for patients in clinical settings.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11136-021-02808-2.

Shared Decision Making: From Decision Science to Data Science

Background. Accurate diagnosis of patients' preferences is central to shared decision making. Missing from clinical practice is an approach that links pretreatment preferences and patient-reported outcomes. Objective. We propose a Bayesian collaborative filtering (CF) algorithm that combines pretreatment preferences and patient-reported outcomes to provide treatment recommendations. Design. We present the methodological details of a Bayesian CF algorithm designed to accomplish 3 tasks: 1) eliciting patient preferences using conjoint analysis surveys, 2) clustering patients into preference phenotypes, and 3) making treatment recommendations based on the posttreatment satisfaction of like-minded patients. We conduct a series of simulation studies to test the algorithm and to compare it to a 2-stage approach. Results. The Bayesian CF algorithm and 2-stage approaches performed similarly when there was extensive overlap between preference phenotypes. When the treatment was moderately associated with satisfaction, both methods made accurate recommendations. The kappa estimates measuring agreement between the true and predicted recommendations were 0.70 (95% confidence interval = 0.052-0.88) and 0.73 (0.56-0.90) under the Bayesian CF and 2-stage approaches, respectively. The 2-stage approach failed to converge in settings in which clusters were well separated, whereas the Bayesian CF algorithm produced acceptable results, with kappas of 0.73 (0.56-0.90) and 0.83 (0.69-0.97) for scenarios with moderate and large treatment effects, respectively. Limitations. Our approach assumes that the patient population is composed of distinct preference phenotypes, there is association between treatment and outcomes, and treatment effects vary across phenotypes. Findings are also limited to simulated data. Conclusion. The Bayesian CF algorithm is feasible, provides accurate cluster treatment recommendations, and outperforms 2-stage estimation when clusters are well separated. As such, the approach serves as a roadmap for incorporating predictive analytics into shared decision making.

Postoperative Thromboprophylaxis With New Oral Anticoagulants is Superior to LMWH in Hip Arthroplasty Surgery: Findings from the Swedish Registry

BACKGROUND

Although the use of thromboprophylaxis is well established, there is no consensus on the preferred thromboprophylaxis regimen after THA; large, population-based studies offer an opportunity to examine this problem in a robust way that can complement results from randomized trials.

QUESTIONS/PURPOSES

Using data from a large national registry, we asked: (1) Is there any difference between low-molecular weight heparin (LMWH) and new oral anticoagulants in preventing symptomatic deep vein thrombosis (DVT) and pulmonary embolism (PE), after THA? (2) Are there any differences in safety parameters, such as bleeding, reoperations and mortality, between LMWH and new oral anticoagulants?

METHODS

Between 2008 and 2012, 78,066 THAs were performed in Sweden. This study evaluated 32,663 (42%) of them, selected through the merger of several national registries. These patients underwent unilateral THA due to primary osteoarthritis. They had not experienced any venous thromboembolic events 5 years before the index operation and were not prescribed potent antithrombotic agents, of any type, in the 6 months before the index operation. Additionally, their postoperative thromboprophylaxis was confirmed in a national registry by purchase of prescribed medications. We divided the cohort into two groups: those patients who received new oral anticoagulants (5752, 18%) and those who received LMWH (26,881, 82%) as postoperative thromboprophylaxis. Our primary endpoints were the frequencies of symptomatic DVT and symptomatic PE within 3 months of surgery. Our secondary comparison was a between-group comparison of bleeding (by way of diagnostic coding), reoperation, and mortality within 3 months of surgery. Odds ratios (OR) are presented with 95% confidence intervals (CIs) as pooled results for the two groups after adjustment for duration of thromboprophylaxis (short or extended for at least 28 days), year of the index operation, Elixhauser comorbidity index, sex, age and previous treatment with platelet aggregation inhibitors.

RESULTS

The risk of symptomatic DVT was lower in the group that received new oral anticoagulants than the group that received LMWH (0.3% versus 0.6%, OR, 0.47; 95% CI, 0.27-0.76; p = 0.026). The risk of symptomatic PE was lower in the group that received new oral anticoagulants than the group that received LMWH (0.1% versus 0.4%, OR, 0.36; 95% CI, 0.16-0.69; p = 0.005). There was no difference in the risk of bleeding (by way of diagnostic coding) (OR, 1.03; 95% CI, 0.82-1.28; p = 0.688), reoperation (OR, 1.02; 95% CI, 0.71-1.44; p = 0.860) or mortality (OR, 0.83; 95% CI, 0.31-1.88; p = 0.883) between groups.

CONCLUSIONS

New oral anticoagulants were associated with a lower risk of symptomatic DVT and symptomatic PE in this large, registry study, and we observed no differences in the risk of bleeding, reoperation, or death between the groups. Although we were able to control for a number of potential confounding variables, we cannot ascertain the indications that drove the prescription decisions in this setting, and there were important between-group differences in terms of duration of thromboprophylaxis (new oral anticoagulants generally were used for a longer period of time after surgery). Future studies, preferably large randomized trials with pragmatic inclusion criteria, to analyze symptomatic DVT, symptomatic PE and death are needed to confirm or refute our findings.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Aspirin: are patients actually taking it?-A quality assessment study

BACKGROUND

The purpose of the study was to assess patient adherence to an aspirin-based prophylactic deep venous thromboembolism (DVT) care management plan after total lower extremity arthroplasty.

METHODS

Using a cross-sectional study design, patients who underwent total hip or knee replacement surgery by a single senior surgeon were surveyed at their routine 6-week follow-up appointment regarding adherence to aspirin DVT prophylaxis. Postoperatively, patients were advised to take 325 mg of aspirin twice daily for 6 weeks to prevent DVT.

RESULTS

Of the 101 patients surveyed, 45 underwent total hip arthroplasty while 56 underwent total knee arthroplasty. There were 48 (48%) patients who were still taking aspirin at their routine 6-week postoperative follow-up appointment and 53 (52%) patients who were not taking aspirin (nonadherent group). Of the latter, 3 (6%) never took aspirin postoperatively, 14 (26%) discontinued within 2 weeks postoperatively, and 23 (43%) did not take it any longer for half the time prescribed. In the nonadherent group, 8 patients reported that they felt they did not need the aspirin prophylaxis, 5 experienced side effects, and 10 were unsure of how long they needed to take it. There was 1 patient with a calf DVT and no episodes of pulmonary embolism.

CONCLUSIONS

Over half of our study, patients did not finish their aspirin regimen. We suggest a consistent outline of medication duration throughout the pre/postop course and communication regarding aspirin cessation.

Health-related quality of life after adverse bleeding events associated with antithrombotic drug therapy - A systematic review

Little is known about the health-related quality of life (HRQOL) following adverse bleeding events associated with antithrombotic drug therapy. This systematic review assesses the HRQOL of patients who suffered a bleeding event related to antithrombotic drug use. A literature search was performed using PubMed, EMBASE, and the Cochrane Library from inception through June 16, 2017. Studies measuring HRQOL after a bleeding event related to antithrombotic drug therapy for primary or secondary prevention of a thromboembolic event were included. Four studies with a total of 13,209 patients met the inclusion criteria, and of them, 3,649 patients developed a bleeding event. Patients who were included received antithrombotic drugs because of acute myocardial infarction or atrial fibrillation. EQ-5D, SF-36, and GHP MOS-13 were used to measure HRQOL. The follow-up time ranged from 6 to 29 months. Patients who suffered a bleeding event reported worse HRQOL compared to those who did not (EQ-5D - average increase on all domains of 0.09, p-values ranging from <0.001 to 0.003; SF-36 - average decrease on all domains of 21.4, p < 0.001; and GHP MOS-13 score - decrease of 11.9 points, p < 0.05) and an increased health concern (13.4-point increase; p < 0.05). In conclusion, adverse bleeding events occurring because of the use of antithrombotic agents are associated with a clinically relevant lower HRQOL and hence deserve more attention as part of the shared decision-making process between patients and providers. These data should be valuable for facilitating more substantive care and risk discussions regarding potential changes in outcome and rehabilitation.

Incidence of symptomatic venous thromboembolism in 2372 knee and hip replacement patients after discharge: data from a thromboprophylaxis registry in Montreal, Canada

Background

Low-molecular-weight heparin (LMWH) is a recommended anticoagulant for thromboprophylaxis after major orthopedic surgery. Dabigatran etexilate is an oral anticoagulant recognized as noninferior to LMWH. We aimed to assess the incidence of symptomatic venous thromboembolic events (VTEs) after discharge in patients who underwent joint replacement, using a hospital registry.

Patients and methods

Patients who underwent total knee and hip arthroplasty between September 2011 and March 2015 were selected. Subcutaneous enoxaparin (30 mg twice daily) was given during hospitalization. At discharge, patients received either enoxaparin 30 mg twice daily/40 mg once daily or dabigatran 220 mg/150 mg once daily. Patients were seen or called at 2, 6, and 12 weeks after surgery. Outcomes were the number of VTEs, including deep venous thrombosis, pulmonary embolism, and the number of major/minor bleeding events after discharge.

Results

After discharge, 1468 patients were prescribed enoxaparin and 904 dabigatran (1396 total knee arthroplasty and 976 total hip arthroplasty patients). Mean age was 66±10 years, and 60% were female. The cumulative incidence of VTEs during the 12-week follow-up was 0.7%. One patient sustained a VTE during the switch window. Seven patients sustained a pulmonary embolism (0.3%). There was no statistical difference between the total knee arthroplasty and total hip arthroplasty groups. The incidence of major and minor bleeding events during follow-up was 0.3% and 30.3%, respectively. These events had a higher incidence in the dabigatran group compared to the enoxaparin group after discharge (p<0.05), but not between knee and hip replacement groups for major bleeding events.

Conclusion

A pharmaceutical prophylaxis protocol using LMWH and dabigatran during the post-discharge period resulted in low incidences of VTE and equivalence between treatments. However, the increased number of major and minor bleeding events in patients taking dabigatran is of concern regarding the safety and needs to be evaluated using analyses adjusted for risk factors.

Safety and Efficacy of New Anticoagulants for the Prevention of Venous Thromboembolism After Hip and Knee Arthroplasty: A Meta-Analysis

BACKGROUND

Venous thromboembolism (VTE) is a common and potentially fatal complication of arthroplasty.

METHODS

We reviewed randomized trials to determine which anticoagulant has the best safety and efficacy in hip and knee arthroplasty patients. We searched PubMed, MEDLINE, and EMBASE through January 2016.

RESULTS

Compared to enoxaparin (most commonly dosed 40 mg once daily), the relative risk (RR) of VTE was lowest for edoxaban 30 mg once daily (0.49; 95% confidence interval [CI], 0.32-0.75), fondaparinux 2.5 mg once daily (0.53; 95% CI, 0.45-0.63), and rivaroxaban 10 mg once daily (0.55; 95% CI, 0.46-0.66), and highest for dabigatran 150 mg once daily (1.19; 95% CI; 0.98-1.44). The RR of major/clinically relevant bleeding was lowest for apixaban 2.5 mg twice daily (0.84; 95% CI; 0.70-0.99) and highest for rivaroxaban (1.27; 95% CI, 1.01-1.59) and fondaparinux (1.64; 95% CI, 0.24-11.35). Fondaparinux was the only agent that was more effective than enoxaparin 30 mg twice daily (VTE RR = 0.58; 95% CI, 0.43-0.76).

CONCLUSION

With the possible exception of apixaban, newer anticoagulants that lower the risk of postoperative VTE increase bleeding.

The compliance of thromboprophylaxis affects the risk of venous thromboembolism in patients undergoing hip fracture surgery

Objective

Venous thromboembolism (VTE) is major problem after hip fracture surgery with substantial morbidity and mortality. This study aimed to assess the postoperative compliance of thromboprophylaxis in elderly patients undergoing hip fracture surgery and to confirm the correlation between compliance and VTE risk.

Methods

This retrospective cohort study included consecutive elderly hip fracture patients who undergoing surgery. According to the thromboprophylaxis regimens, patients were divided into non-compliant group (<14days), poor compliant group (14–27days) and good compliant group (≥28days). The primary outcome was the incidence of symptomatic DVT, PE within 6weeks postoperatively.

Results

Between 2008 and 2012, 1214 eligible patients were included in this study. 761 (64.7%) patients were non-compliant, 224 (19.0%) patients were poor compliant, and 192 (16.3%) patients were good compliant. The overall VTE rate was 7.9% (73/1177), PE rate was 0.3% (4/1177). The VTE rate in good compliant group was lowest among three groups (4.2 vs. 5.4 vs. 9.6%, P=0.013), but the PE rates showed no significant differences (0 vs. 0.9 vs. 0.3%, P=0.241). The multivariate analysis showed that non-compliance was an independent risk factor of suffering VTE undergoing hip fracture surgery.

Conclusions

In this study we found fewer than 1 in 5 patients maintained compliant with thromboprophylaxis guidelines after discharge following hip surgery. This is particularly concerning because those who were non-compliant had a higher risk of VTE postoperatively compared with those who were good compliant.

Patients' perception about risks and benefits of antithrombotic treatment for the prevention of venous thromboembolism (VTE) after orthopedic surgery: a qualitative study

Background

The 9th edition of the American College of Chest Physicians’ Antithrombotic Therapy and Prevention of Thrombosis guidelines emphasize the importance of considering the risk–benefit ratio of “patient-important” outcomes. However, little is known about patients’ perception and understanding regarding the different outcomes of antithrombotic treatment after orthopedic surgery, and the factors that influence their decision to use these treatments. Using a series of semi-structured interviews, we explored patients’ understanding and perception concerning the benefits and risks of antithrombotic treatment for the prevention of venous thromboembolism (VTE) after joint replacement surgery.

Methods

A series of semi-structured interviews were conducted with patients who had undergone knee or hip replacement surgery at a tertiary care hospital (Brigham and Women’s Hospital, Boston, MA) in 2014. Discussions were recorded and transcribed. Two investigators independently coded and analyzed the data to identify important themes and concepts using the constant comparative method.

Results

Of 64 patients who were invited, 12 patients (19 %) completed the interviews. The majority of patients (92 %) were aware of the benefits of antithrombotic therapy for reducing the risk of blood clots, while less than half of them had a clear understanding of deep vein thrombosis and pulmonary embolism. While all patients were aware of risk of minor bleeding, only 6 patients (50 %) considered the risk of major bleeding as a possible side effect of antithrombotic treatment. Overall, patients perceived bleeding as a less important outcome than a thrombotic event. The lack of awareness about the risk of major bleeding, the assumption that a short-term exposure would not meaningfully affect bleeding risk, and the assumption that bleeding is a controllable event influenced their perception. Most patients (83 %) stated that their decision to use antithrombotic medications was mainly based on the trust in their physician’s expertise.

Conclusions

Patients perceived thrombotic events as more important outcomes than bleeding events. Patients’ understanding of thrombotic and bleeding events varies and may play a key role in their preferences. The majority of patients stated that trust in their physician’s expertise had a large influence on their decision to use antithrombotic medications.

Direct-acting oral anticoagulants: pharmacology, indications, management, and future perspectives

In recent years, several direct-acting oral anticoagulants (DOAC) have become available for use in Europe and other regions in indications related to prophylaxis and treatment of venous and arterial thromboembolism. They include the oral direct thrombin inhibitor dabigatran etexilate (Pradaxa, Boehringer Ingelheim) and the oral direct FXa inhibitors rivaroxaban (Xarelto, Bayer HealthCare), apixaban (Eliquis, Bristol-Myers Squibb), and edoxaban (Lixiana/Savaysa, Daiichi-Sankyo). The new compounds have a predictable dose response and few drug-drug interactions (unlike vitamin k antagonists), and they do not require parenteral administration (unlike heparins). However, they accumulate in patients with renal impairment, lack widely available monitoring tests for measuring its anticoagulant activity, and no specific antidotes for neutralization in case of overdose and/or severe bleeding are currently available. In this review, we describe the pharmacology of the DOAC, the efficacy, and safety data from pivotal studies that support their currently approved indications and discuss the postmarketing experience available. We also summarize practical recommendations to ensure an appropriate use of the DOAC according to existing data. Finally, we discuss relevant ongoing studies and future perspectives.

Current and emerging strategies in the management of venous thromboembolism: benefit-risk assessment of dabigatran

Venous thromboembolism (VTE) is a disease state that carries significant morbidity and mortality, and is a known cause of preventable death in hospitalized and orthopedic surgical patients. There are many identifiable risk factors for VTE, yet up to half of VTE incident cases have no identifiable risk factor and carry a high likelihood of recurrence, which may warrant extended therapy. For many years, parenteral unfractionated heparin, low-molecular weight heparin, fondaparinux, and oral vitamin K antagonists (VKAs) have been the standard of care in VTE management. However, limitations in current drug therapy options have led to suboptimal treatment, so there has been a need for rapid-onset, fixed-dosing novel oral anticoagulants in both VTE treatment and prophylaxis. Oral VKAs have historically been challenging to use in clinical practice, with their narrow therapeutic range, unpredictable dose responsiveness, and many drug-drug and drug-food interactions. As such, there has also been a need for novel anticoagulant therapies with fewer limitations, which has recently been met. Dabigatran etexilate is a fixed-dose oral direct thrombin inhibitor available for use in acute and extended treatment of VTE, as well as prophylaxis in high-risk orthopedic surgical patients. In this review, the risks and overall benefits of dabigatran in VTE management are addressed, with special emphasis on clinical trial data and their application to general clinical practice and special patient populations. Current and emerging therapies in the management of VTE and monitoring of dabigatran anticoagulant-effect reversal are also discussed.

Patient preferences for disease-modifying drugs in multiple sclerosis therapy: a choice-based conjoint analysis

OBJECTIVES

With an increasing number of disease-modifying treatments (DMTs) for multiple sclerosis (MS), patient preferences will gain importance in the decision-making process. We assessed patients' implicit preferences for oral versus parenteral DMTs and identified factors influencing patients' treatment preference.

METHODS

Patients with relapsing-remitting MS (n = 156) completed a questionnaire assessing treatment preferences, whereby they had to decide between pairs of hypothetical treatment scenarios. Based on this questionnaire a choice-based conjoint analysis was conducted.

RESULTS

Treatment frequency and route of administration showed a stronger influence on patient preference compared with frequency of mild side effects. The latter attribute was more important for treatment-naïve patients compared with DMT-experienced patients. The higher the Extended Disability Status Scale score, the more likely pills, and the less likely fewer side effects were preferred. Pills were preferred over injections by 93% of patients, when treatment frequency and frequency of side effects were held constant. However, preference switched to injections when pills had to be taken three times daily and injections only once per week. Injections were also preferred when pills were associated with frequent side effects.

CONCLUSIONS

Our results suggest that route of administration and treatment frequency play an important role in the patients' preference for a given DMT.

[Patient pathways in thrombosis prophylaxis after hip and knee replacement surgery : results of a survey]

A key element of patient care after hip and knee replacement is medication-based thrombosis prophylaxis. Due to decreasing lengths of acute hospital stays the question arises to what extent outpatients are taking responsibility thrombosis prophylaxis (patient pathway analysis).To analyze patient pathways a telephone survey of 668 patients was conducted. On average patients were interviewed 38 days following surgery with a focus on low molecular weight heparins. The analysis showed that nearly 90% of patients need to carry out thrombosis prophylaxis in an outpatient or home environment for at least 1 day and for 47.2% of patients a linking period between acute and rehabilitation stay is relevant. The obviously existing quantitative importance of outpatient thrombosis prophylaxis is also reflected by its duration and 45.7% of interviewed patients needed at least 5 days of outpatient prophylaxis.Outpatient thrombosis prophylaxis clearly makes high demands on the patients, in particular when combined with the task of administering complex forms of injections. Those involved in inpatient and outpatient provision of care should not assume that all patients carry out the necessary prophylaxis at the required level of reliability. On the contrary initial evidence shows that the non-adherence of patients during ambulatory thrombosis prophylaxis presents a genuine challenge to care providers.

Pharmacoeconomics of dabigatran etexilate for prevention of thromboembolism after joint replacement surgery

Dabigatran etexilate (DE) is a novel oral anticoagulant indicated for the prevention of venous thromboembolism in patients undergoing total hip or total knee replacement surgery. The majority of these patients receive some kind of thromboprophylaxis, most commonly low-molecular-weight heparin (LMWH). However, the subcutaneous route of LMWH administration may act as a barrier to the continuation of effective anticoagulant prophylaxis after discharge from hospital. The oral route of DE administration may allow more patients to receive extended thromboprophylaxis and may reduce costs, such as those associated with nurse time for LMWH administrations, platelet monitoring, needlestick injuries and sharps disposal. This article presents an overview of the clinical evidence for DE and a systematic review of the economic evaluations of the drug.

Nonadherence in outpatient thrombosis prophylaxis with low molecular weight heparins after major orthopaedic surgery

BACKGROUND

According to some current guidelines, extended thromboprophylaxis after hip and knee arthroplasties is recommended. Outpatient prophylaxis with low molecular weight heparins (LMWH) is an important part of this prophylaxis, although the rates of adherence to these regimens is not known.

QUESTIONS/PURPOSES

We determined (1) the degree of nonadherence (NA) of patients with LMWH outpatient prophylaxis, and (2) whether specific independent factors explain NA.

METHODS

NA was determined by syringe count and by indirect and direct questions to patients. We defined six different NA indicators. To identify factors explaining LMWH NA, we used three different logistic regression models.

RESULTS

NA rates ranged between 13% and 21% depending on the indicator used for measurement. Patients who were nonadherent missed between 38% and 53% of their outpatient LMWH injections. If patients attended an outpatient rehabilitation program, the probability for their NA increased substantially. Moreover, the NA probability increased with each additional day between acute hospitalization and start of rehabilitation (linking days). NA was lower for patients who feared thrombosis or who believed antithrombotic drugs to be the most important measure in thromboprophylaxis.

LEVEL OF EVIDENCE

Level II, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.