Treatment of heparin-induced thrombocytopenia before and after the implementation of a hemostatic and antithrombotic stewardship program

The Impact of an Antithrombotic Stewardship Program on Heparin-Induced Thrombocytopenia Management

Background: An antithrombotic stewardship program was implemented to reduce IV DTI use and increase fondaparinux and direct oral anticoagulant (DOAC) use for suspected or confirmed Heparin-induced thrombocytopenia (HIT). Objectives: This study evaluated the impact of an antithrombotic stewardship program on IV DTI utilization in patients with HIT. Methods: A retrospective analysis of adults receiving IV DTIs or fondaparinux from July 2016 to July 2017 (pre-stewardship) and October 2017 to July 2019 (post-stewardship) was conducted. Results: The median duration of IV DTI administration was not significantly different in HIT-negative patients between the pre- and post-stewardship cohorts (1.6 days (25th percentile (p25), 75th percentile (p75): .5, 3.3) vs 1.7 days (p25, p75: .9, 3.9), P = .31). The median duration of IV DTI administration in HIT-positive patients was 9.9 days (p25, p75: 7.6, 21.0) pre-stewardship and 7.3 days (p25, p75: 4.8, 16.5) post-stewardship (P = .18). For HIT-positive patients, the time from HIT diagnosis to discharge was 12.8 days (p25, p75: 8.9, 24.9) and 9.2 days (p25, p75: 4.0, 18.1) in the pre- and post-stewardship cohorts, respectively (P = .07). Fondaparinux and DOAC prescribing rates were 40.7% and 62.2% in the pre- and post-stewardship cohorts, respectively (P = .09). The percentage of patients with no contraindications to IV DTI alternatives receiving these agents increased from 31.2% to 78.6% (P = .01) following stewardship implementation. Conclusions: Intravenous DTI alternative utilization increased significantly after stewardship implementation. Stewardship implementation was associated with a non-statistically significant trend towards decreased IV DTI utilization and decreased length of stay for HIT-positive patients.

Quality improvement approaches to heparin-induced thrombocytopenia: a scoping review

Background

Heparin-induced thrombocytopenia (HIT) is a relatively uncommon condition characterized by 2 exceedingly common phenomena in hospitalized patients: thrombocytopenia and heparin exposure. Consequently, HIT is frequently overdiagnosed and inappropriately treated. These issues are the focus of many quality improvement (QI) initiatives.

Objectives

In this scoping review, we identified and characterized all published QI studies on improving the diagnosis and management of HIT.

Methods

We conducted a systematic literature search through April 2022 for studies reporting on QI interventions regarding the diagnosis, treatment, and/or prevention of HIT.

Results

Thirty studies were included in the final review. Studies were separated into 5 groups based on the focus of the interventions: increasing HIT recognition, reducing HIT incidence, reducing HIT overdiagnosis, promoting safer HIT management, and creating HIT task forces. Nine studies focused on the implementation of 4Ts score calculator into electronic medical record orders for HIT testing, while only 1 evaluated the impact of reducing unfractionated heparin use in favor of low-molecular-weight heparin. Six studies focused on the implementation of direct thrombin inhibitor management protocols, while none evaluated the use of alternative anticoagulants in HIT management.

Conclusion

The bulk of published HIT QI research focused on reducing overdiagnosis and promoting safer direct thrombin inhibitor therapy, while minimal attention has been devoted to HIT prevention and the use of evidence-based alternative HIT therapies.

Anticoagulation-Associated Adverse Drug Events in Hospitalized Patients Across Two Time Periods

PURPOSE

Anticoagulants often cause adverse drug events (ADEs), comprised of medication errors and adverse drug reactions, in patients. Our study objective was to determine the clinical characteristics, types, severity, cause, and outcomes of anticoagulation-associated ADEs from 2015-2020 (a contemporary period following implementation of an electronic health record, infusion device technology, and anticoagulant dosing nomograms) and to compare them with those of a historical period (2004-2009).

METHODS

We reviewed all anticoagulant-associated ADEs reported as part of our hospital-wide safety system. Reviewers classified type, severity, root cause, and outcomes for each ADE according to standard definitions. Reviewers also assessed events for patient harm. Patients were followed up to 30 days after the event.

RESULTS

Despite implementation of enhanced patient safety technology and procedure, ADEs increased in the contemporary period. In the contemporary period, we found 925 patients who had 984 anticoagulation-associated ADEs, including 811 isolated medication errors (82.4%); 13 isolated adverse drug reactions (1.4%); and 160 combined medication errors, adverse drug reactions, or both (16.2%). Unfractionated heparin was the most frequent ADE-related anticoagulant (77.7%, contemporary period vs 58.3%, historical period). The most frequent anticoagulation-associated medication error in the contemporary period was wrong rate or frequency of administration (26.1%, n = 253), with the most frequent root cause being prescribing errors (21.3%, n = 207). The type, root cause, and harm from ADEs were similar between periods.

CONCLUSIONS

We found that anticoagulation-associated ADEs occurred despite advances in patient safety technologies and practices. Events were common, suggesting marginal improvements in anticoagulant safety over time and ample opportunities for improvement.

Reducing Inappropriate Simultaneous Ordering of Heparin Antibody and Serotonin Release Assays

INTRODUCTION

A 4T score with intermediate or high probability of heparin-induced thrombocytopenia prompts ordering of anti-platelet 4 heparin complex. If positive, a serotonin release assay (SRA) is recommended to confirm diagnosis. Despite these recommendations, overtesting of both anti-platelet 4 and SRA is highly prevalent.

METHODS

This was a quality improvement initiative using two forms of clinical decision support across 11 acute care hospitals. First, a 4T calculator was incorporated into anti-platelet 4 orders. Second, a Best Practice Advisory fired when anti-platelet 4 and SRA were ordered simultaneously, prompting the provider to remove the SRA order. Data were analyzed by a quasi-experimental interrupted time series linear regression comparing weekly average laboratory tests per 1,000 patient-days pre- and postintervention.

RESULTS

Average ordering frequency of anti-platelet 4 changed from 0.508 to 0.510 per 1,000 patient-days (0.5%, p = 0.42) without significant slope or level differences. Average ordering frequency of SRA decreased from 0.430 to 0.289 per 1,000 patient-days (32.8%, p < 0.001) with a significant level difference of -0.128 orders per 1,000 patient-days (-31.2%, p < 0.05).

CONCLUSION

A simultaneous Best Practice Advisory was effective in reducing SRA orders, but not anti-platelet 4 orders.

Impact of Hospital-based Multidisciplinary Anticoagulation Stewardship Programs

Antithrombotic therapies, especially anticoagulants, are high-risk medications with increased potential for adverse events. The development and implementation of a well-functioning, designated, multidisciplinary anticoagulation stewardship program (MASP), tailored to each hospital-center's needs, has the primary objectives of improving patient-centered outcomes, minimizing undesirable anticoagulation-related adverse events and minimizing hospital length of stay (LOS) and other patient-related costs. Such stewardship programs are pivotal in supporting busy clinicians with consultation on challenging clinical case scenarios, ensuring appropriate use of valuable healthcare resources, achieving compliance with anticoagulant-associated accreditation standards, and positively impacting patient-specific morbidity/mortality outcomes. Herein, we review and discuss the critical need for antithrombosis stewardship and the benefit of formalized MASP in optimizing use of antithrombotic therapies.

Measuring the Impact of a Pharmacist-Driven Blood Factor Education Program: A Prospective, Single-Center Observational Study

Introduction: Patients with bleeding disorders are best served by multidisciplinary teams. Pharmacists can play a critical role in the optimal management of patients with bleeding disorders through blood factor stewardship strategies and programs. An educational program was developed and implemented wherein a hematology pharmacist provided brief recorded lectures to an entire department of pharmacists in a multi-site health-system with the goal to improve the knowledge base and confidence among this population of general practitioners. Methods: The primary objective of this study was to evaluate the educational outcomes of a blood factor education program for pharmacists. The impact of the educational program was determined by measuring the difference in mean test scores between the pre- and post-program surveys. Results: The final analysis included 214 participants. The primary endpoint of mean competency test score was significantly improved in the post-test compared to pre-test (78.33% vs 52.83%; P < .0001). Any degree of test score improvement was observed in 99% ( n = 212) of participants. Pharmacist confidence was significantly improved in all 20 domains of bleeding disorders and blood factor product verification and management. Conclusion: This program identified that most pharmacists in a large multi-site health-system were not familiar with bleeding disorders to a satisfactory degree, commonly because of the relative rare encounters with bleeding disorder-related orders, and that despite systems-based support there was an opportunity to improve practice through education. Such educational programming could be beneficial for the development of pharmacist-provided care and is a measure that could be implemented as part of blood factor stewardship initiatives.

Evaluation of the use of direct oral anticoagulants for the management of heparin-induced thrombocytopenia

Historically, treatment of heparin-induced thrombocytopenia (HIT) includes a non-heparin parenteral anticoagulant with bridging to warfarin once platelets recover. Data supporting the use of direct oral anticoagulants (DOACs) for HIT treatment are limited. Given the paucity of evidence for the use of DOACs in HIT, the aim of this study is to describe the prescribing patterns of DOACs for HIT at our institution. This is a single center, retrospective chart evaluation of patients admitted from January 2017 to October 2020 with a confirmed diagnosis of HIT. Twenty-six patients were identified; 21 patients (81%) received initial parenteral treatment and 5 patients (19.2%) with initial DOAC treatment. The most frequently used DOAC was apixaban at the VTE treatment dose [15 (57.7%)] followed by the reduced dose of apixaban [5 (19.2%)]. Of the patients initially treated with a parenteral agent, 11 (42.3%) were transitioned to a DOAC after platelet recovery, 7 (26.9%) transitioned as platelets were steadily increasing, and 3 (11.5%) transitioned at the time of discharge (prior to platelet recovery). Platelet recovery was achieved in 23 patients (88.5%) at a median of 5 days (IQR 2.8-8.3) after HIT diagnosis. No new thrombotic or bleeding events occurred within 30 days of HIT diagnosis. In our patients treated with a DOAC for HIT, no progression of HIT was observed. Apixaban was the most frequently utilized DOAC. Most patients received a parenteral anticoagulant prior to DOAC initiation. All patients managed with a DOAC as initial treatment achieved platelet recovery within 30 days of HIT diagnosis.

Development and implementation of venous thromboembolism stewardship across a hospital network

BACKGROUND

Venous thromboembolism (VTE) is a leading cause of preventable death in hospital. Ensuring all hospitalized patients are assessed for VTE risk and given appropriate prophylaxis can reduce the burden of VTE on patients and the healthcare system. This is the first study to explore the effectiveness of a VTE stewardship program using electronic clinical decision support (eCDS) to provide oversight of hospital initiatives to prevent VTE.

AIM

To determine if a VTE stewardship program can increase risk-appropriate VTE prophylaxis, VTE risk assessment using eCDS, any documented risk assessment and risk assessment within 24 h of admission, plus reduce the incidence of hospital acquired VTE (HA-VTE).

METHODS

Education, daily medication chart auditing, weekly clinician performance feedback, health promotion and gamification were deployed over 6 months by two multidisciplinary VTE stewardship teams across four hospitals. Service impact was assessed through cross-sectional audits of electronic medical records every 3 months and review of HA-VTE events pre- and post-intervention. Implementation costs were calculated.

RESULTS

A total of 1622 patients were audited in separate cohorts at baseline, 3, 6 and 9 months. There was significant improvement in the prescription of appropriate prophylaxis (78%, 83%, 84%, and 88%, p = 0.004), VTE risk assessment using the eCDS tool (20%, 50%, 81% and 87%, p < 0.001), any documented risk assessment (71%, 82%, 95% and 93%, p < 0.001) and any documented risk assessment within 24 h of admission (54%, 56%, 65% and 63%, p = 0.001). Use of eCDS was associated with prescription of risk-appropriate VTE prophylaxis (p < 0.001). Annual incidence of HA-VTE decreased from 7.88 to 6.99 events per 10,000 discharges pre- to post-intervention (Odds Ratio (OR) 0.89, 95 %CI 0.66-1.18, p = 0.43). The cost of implementing the program across 133,078 episodes of care during the study period was AUD$108,167 (mean cost of $0.82 per patient).

Impact of a multidisciplinary workflow on safety and management of patients with heparin-induced thrombocytopenia

PURPOSE

Heparin-induced thrombocytopenia (HIT) is a serious complication of heparin administration. Management strategies are complex and include discontinuing heparin products, initiating alternative anticoagulants, interpreting laboratory test results, documenting heparin allergies, and providing patient education. Medication error reports and a retrospective review conducted at an academic medical center revealed an opportunity for a quality improvement initiative and led to the creation of a multidisciplinary workflow for the management of HIT. In a pre-post study, the impact of the multidisciplinary workflow on the safety and management of HIT was evaluated.

METHODS

The preimplementation group consisted of adult patients tested for suspected HIT from April 4, 2014, through May 31, 2016; the postimplementation group consisted of adult patients tested from November 1, 2016, through October 31, 2018. The primary outcome was the incidence of heparin product administration while HIT testing was ongoing. The secondary outcome was the rate of appropriate heparin allergy documentation.

RESULTS

The incidence of heparin product administration while HIT testing results were pending was significantly reduced, from 54.2% to 20.0% (P < 0.001), after workflow implementation. The rate of appropriate heparin allergy documentation significantly increased, from 95.0% to 100% (P < 0.001).

CONCLUSION

Implementation of a multidisciplinary workflow for the management of HIT significantly reduced the incidence of heparin administration while testing was ongoing and improved the rate of appropriate heparin allergy documentation.

Methods of sample size calculation in descriptive retrospective burden of illness studies

Background

Observational burden of illness studies are used in pharmacoepidemiology to address a variety of objectives, including contextualizing the current treatment setting, identifying important treatment gaps, and providing estimates to parameterize economic models. Methodologies such as retrospective chart review may be utilized in settings for which existing datasets are not available or do not include sufficient clinical detail. While specifying the number of charts to be extracted and/or determining whether the number that can feasibly extracted will be clinically meaningful is an important study design consideration, there is a lack of rigorous methods available for sample size calculation in this setting. The objective of this study was to develop recommended sample size calculations for use in such studies.

Methods

Calculations for identifying the optimal feasible sample size calculations were derived, for studies characterizing treatment patterns and medical costs, based on the ability to comprehensively observe treatments and maximize precision of resulting 95% confidence intervals. For cost outcomes, if the standard deviation is not known, the coefficient of variation cv can be used as an alternative. A case study of a chart review of advanced melanoma (MELODY) was used to characterize plausible values for cv in a real-world example.

Results

Across sample sizes, any treatment given with greater than 1% frequency has a high likelihood of being observed. For a sample of size 200, and a treatment given to 5% of the population, the precision of a 95% confidence interval (CI) is expected to be ±0.03. For cost outcomes, for the median cv value observed in the MELODY study (0.72), a sample size of approximately 200 would be required to generate a 95% CI precise to within ±10% of the mean.

Conclusion

This study presents a formal guidance on sample size calculations for retrospective burden of illness studies. The approach presented here is methodologically rigorous and designed for practical application in real-world retrospective chart review studies.

Electronic supplementary material

The online version of this article (10.1186/s12874-018-0657-9) contains supplementary material, which is available to authorized users.

Limited impact of clinician education on reducing inappropriate PF4 testing for heparin-induced thrombocytopenia

A high frequency of PF4-ELISA testing in patients suspected to have heparin-induced thrombocytopenia (HIT) despite low 4T scores has been observed in multiple medical centers. Education of clinicians has been suggested to reduce inappropriate testing. We determined trends of PF4-ELISA testing in our institution after the introduction of a HIT education program for clinicians. A HIT Program was developed that included ongoing education, individual feedback, and continuous clinical audit of PF4-ELISA utilization. To assess the impact of education on PF4-ELISA testing trends, we conducted a prospective cohort review of all adult patients who had a PF4-ELISA ordered over a 3 month period (the last quarter of the academic year). 72 PF4-ELISA tests were ordered during the study period. Prospectively calculated 4T scores by investigators revealed 60 low-risk (83.3%), 9 intermediate-risk (12.5%), and 3 high-risk (4.16%). We observed divergent 4T scores with the ordering clinician calculating a higher 4T score compared to the Hematology Quality Improvement (QI) team. The majority of PF4-ELISA testing was ordered by the intensive care units (ICUs) (n = 32, 44.44%). Our study revealed that the frequency of calculation of 4T scores remains poor with the majority inappropriately performed in the ICU setting, with ordering clinicians calculating higher 4T scores than the Hematology QI team. This suggests that clinician education alone is insufficient. Introducing mandatory 4T score calculation prior to PF4-ELISA testing may not be helpful as ordering clinicians can bypass the restriction through inaccurate 4T score calculation.

Initial and long term impact of a multi-disciplinary task force in the diagnosis and management of heparin-induced thrombocytopenia

Many medical centers are faced with a major challenge in making an accurate diagnosis of heparin-induced thrombocytopenia (HIT) and ensuring appropriate changes in management strategy in line with guideline recommendations. We report the initial and long-term impact and challenges of institution-wide changes in the diagnosis and management of HIT in the inpatient setting at an academic medical center. We established a HIT Task Force, consisting of a multidisciplinary team of non-malignant hematologists, nursing, pharmacist, pathology, blood bank and clinical lab informatics. Changes were implemented from 2011 to 2012. In 2013, testing for PF4 and SRA decreased by 37.5 and 85%, respectively. 100% of positive PF4 received an automatic hematology consult to guide management, leading to a 78% reduction in the use of direct thrombin inhibitors. Annual audits in the subsequent years demonstrated increasing testing for HIT due to changes in the electronic ordering system. Through continuous monitoring, these shortfalls were detected and intervene early on with continued success. The implementation of a centralized hospital-wide protocol via a multidisciplinary task force that coordinates testing and treatment of patients suspected of having HIT led to a substantial reduction in PF4 and SRA testing, as well as use of DTIs, resulting in a safe and cost-effective approach for the diagnosis and treatment of HIT. Our study highlights the important of continuous monitoring to maintain the improvements made. Despite our initial success, annual re-auditing allowed for early detection of challenges, which then allowed appropriate early intervention.

Implementation of a rapid HIT immunoassay at a university hospital - Retrospective analysis of HIT laboratory orders in patients with thrombocytopenia

BACKGROUND

Heparin-induced thrombocytopenia (HIT) is a rare cause of thrombocytopenia and a potentially life-threatening adverse drug reaction. Clinical overdiagnosis of HIT results in costly laboratory tests and anticoagulation. Criteria and algorithms for diagnosis are established, but their translation into clinical practice is still challenging.

STUDY DESIGN AND METHODS

In a retrospective approach we studied all HIT related laboratory test requests within four years and evaluated data before (1st period, 24month) and after (2nd period, 24month) replacing particle gel immunoassay (PaGIA) and enzyme-linked immunosorbent assay (ELISA) by a chemiluminescent immunoassay (CLIA). HIT was confirmed by heparin-induced platelet activation (HIPA) test. Clinical pretest probability for HIT using an implemented simplified 4Ts score and platelet count were evaluated. Costs for laboratory tests and alternative anticoagulation were calculated.

RESULTS

In 1850 patients with suspected HIT, 2327 laboratory orders were performed. In 87.2% of these orders an intermediate/high simplified 4Ts score was found. Thrombocytopenia was present in 87.1%. After replacing PaGIA and ELISA by CLIA the number of immunological and functional laboratory tests was reduced by 38.2%. The number of positive HIT immunoassays declined from 22.6% to 6.0%, while the number of positive HIPA tests among positive immunological tests increased by 19%. Altogether, acute HIT was confirmed in 59 patients. A decline in the use of alternative anticoagulants was observed in the 2nd period.

CONCLUSION

Our study shows that in a university hospital setting HIT is well-known, but diagnosis requires a precise laboratory confirmation. Replacing PaGIA and ELISA by CLIA did not influence laboratory order behavior but results in reduced overall costs for laboratory diagnostics and alternative anticoagulation.