Engaging with quality improvement in anticoagulation management

Comparison of anticoagulation control and outcomes between usual medical care and pharmacist-led anticoagulation service in ambulatory patients taking warfarin at tertiary hospital in Ethiopia: a quasi-experimental study

BACKGROUND

We aimed to compare anticoagulation control and outcomes between usual medical care (UMC) and pharmacist-led anticoagulation services (PLAS) in patients receiving warfarin at the Tikur Anbessa Specialized Hospital (TASH), Addis Ababa, Ethiopia.

METHODS

A quasi-experimental study was conducted, including 350 (66.7%) and 175 (33.3%) patients from the UMC and PLAS groups, respectively, from 525 patients. The time in therapeutic range (TTR) was determined using the Rosendaal method, with a TTR ≥ 65% set as the cut-off for optimal anticoagulation. The two-sample Wilcoxon rank-sum (Mann-Whitney U) test was used to compare continuous variables between groups. Categorical variables were compared between groups using Pearson's chi-square test or Fisher's exact test. Logistic regression and negative binomial regression analyses were conducted to identify the factors associated with suboptimal TTR and secondary outcomes, respectively, at the p values < 0.05, and 95% confidence interval (CI).

RESULTS

Compared with the UMC group, the patients in the PLAC group showed a significantly higher median (IQR) TTR [60.89% (43.5-74.69%) vs. 53.65% (33.92-69.14%), p < 0.001]. A significantly higher optimal TTR (≥ 65%) was achieved in the PLAC group (41.7% vs. 31.7%) than in the UMC group (p = 0.002). The odds of having a poor TTR were reduced by 43% (AOR = 0.57, 95% CI = 0.36-0.88, p = 0.01) among patients in the PLAC group compared to those in the UMC group. There were no statistically significant differences in the secondary outcomes between the groups, except for all-cause emergency visits (p = 0.003). The incidence of bleeding events decreased by 3% (IRR = 0.97, 95% CI = 0.96-0.99, p < 0.001) for every increase in INR monitoring frequency. The incidence of thromboembolic events increased by a factor of 15.13 (IRR = 15.13, 95% CI = 1.47-155.52, p = 0.02) among patients with a high-risk CHA2DS2-VASc score compared with those with a moderate score.

CONCLUSION

Patients in the PLAC group had a significantly higher median TTR than those in the UMC group did. There were no statistically significant differences in the secondary outcomes between the groups, except for fewer all-cause emergency department visits in the PLAC group.

Prevalence of Guideline-Discordant Aspirin Use and Associated Adverse Events in Patients on Warfarin for Mechanical Valve Replacement

BACKGROUND

For patients on warfarin for mechanical heart valve replacement, the 2020 American College of Cardiology and American Heart Association Guidelines recommend only adding aspirin in patients with a specific indication for antiplatelet therapy. This contrasts with prior guidelines, which recommended concomitant aspirin therapy. We sought to assess the prevalence of guideline-discordant aspirin use among patients on warfarin for mechanical heart valve replacement and to compare adverse event rates among patients with and without concomitant aspirin.

METHODS

Patients on warfarin for mechanical heart valve replacement were identified from the Michigan Anticoagulation Quality Improvement Initiative registry. Patients with myocardial infarction, percutaneous coronary intervention, or coronary artery bypass within the past 12 months were excluded. Patients were divided into 2 groups based on aspirin use. Patient characteristics and bleeding and thromboembolic outcomes were compared.

RESULTS

Four hundred forty-four patients met the inclusion criteria, with 341 (76.8%) on concomitant aspirin. The aspirin group was older (50.6 vs 46.3 years, P = .028) and had more hypertension (57.8% vs 46.6%, P = .046) but other patient characteristics were similar. The aspirin group had a higher rate of bleeding events (28.3 vs 13.3 per 100 patient-years, P < .001) and bleed-related emergency department visits (11.8 vs 2.9 per 100 patient-years, P = .001) compared with the non-aspirin group. There was no observed difference in rates of ischemic stroke (0.56 vs 0.48 per 100 patient-years, P = .89).

CONCLUSIONS

A significant proportion of patients on warfarin for mechanical heart valve replacement are on guideline-discordant aspirin. Aspirin deprescribing in select patients may safely reduce bleeding events.

Outcomes of direct oral anticoagulants with aspirin vs warfarin with aspirin: a registry-based cohort study

Background

For patients anticoagulated with direct oral anticoagulants (DOACs) or warfarin and on aspirin (ASA) for nonvalvular atrial fibrillation and/or venous thromboembolism, it is unclear if bleeding outcomes differ.

Objectives

To assess bleeding rates for ASA with DOACs vs warfarin and one another.

Methods

Registry-based cohort study of patients followed by a 6-center quality improvement collaborative in Michigan using data from 2009 to 2022. The study included adults on ASA with warfarin or DOACs for atrial fibrillation and/or venous thromboembolism without a recent myocardial infarction or heart valve replacement.

Results

After propensity matching by anticoagulant class, we compared 2 groups of 1467 patients followed for a median of 18.0 months. Any bleeding and nonmajor bleeding was increased with DOACs + ASA compared with warfarin + ASA (32.2 vs 27.8 and 27.1 vs 22.9 events/100 patient-years; relative risks [RRs], 1.1 and 1.2; 95% CIs, 1.1-1.2 and 1.1-1.3, respectively). After matching by drug, patients on apixaban + ASA vs warfarin + ASA had more bleeding (31.2 vs 27.8 events/100 patient-years; RR, 1.1; 95% CI, 1.0-1.2) and nonmajor bleeding but less major bleeding (3.8 vs 4.7 events/100 patient-years; RR, 0.8; 95% CI, 0.6-1.0) and emergency room visits for bleeding. Patients on rivaroxaban + ASA vs warfarin + ASA had more bleeding (39.3 vs 26.3 events/100 patient-years, RR, 1.5; 95% CI, 1.3-1.6), nonmajor bleeding, and thrombosis. Patients on apixaban + ASA vs rivaroxaban + ASA had significantly less bleeding (22.5 vs 39.3/100 patient-years; RR, 0.6; 95% CI, 0.5-0.7), nonmajor bleeding, major bleeding (2.1 vs 5.5 events/100 patient-years; RR, 0.4; 95% CI, 0.2-0.6), emergency room visits for bleeding, and thrombotic events.

Conclusion

Patients on DOAC + ASA without a recent myocardial infarction or heart valve replacement had more nonmajor bleeding but otherwise similar outcomes compared with warfarin + ASA. Patients treated with rivaroxaban + ASA experienced more adverse clinical events compared with warfarin + ASA or apixaban + ASA.

Knowledge, Adherence, and Satisfaction With Warfarin Therapy and Associated Factors Among Outpatients at University Teaching Hospital in Ethiopia

Anticoagulation management using warfarin is challenging in clinical practice. This study aimed to evaluate the knowledge, adherence, and satisfaction with warfarin therapy and associated factors among outpatients at the Tikur Anbessa Specialized Hospital (TASH) in Addis Ababa, Ethiopia. An interview-based cross-sectional study was conducted among 350 patients receiving warfarin therapy at cardiac and hematology clinics of TASH. Anticoagulation knowledge assessment (AKA) questionnaires assessed the patients' warfarin knowledge. Adherence to warfarin was evaluated using the Morisky Green Levine Scale (MGLS), and patient satisfaction with warfarin therapy was assessed using the 17-item anticlot treatment scale (ACTS). Binary logistic regression was used to determine factors associated with the outcome variables, and p < .05 was used as the cut-off point to declare a significant association. The mean AKA score was 59.35  ±  13.04% (10.68  ±  2.34 correct answers), and 82 (23.4%) of participants achieved a passing score. Based on the MGLS, 192 (54.9%) study participants adhered well to warfarin. The mean level of satisfaction was 53.67  ±  8.56, with mean scores of 41.93  ±  7.80 and 11.74  ±  2.43 in the ACTS burden and benefit subscales, respectively. One hundred eighty-four (52.6%) patients were satisfied with warfarin therapy. The absence of hyperthyroidism was significantly associated with poor knowledge of warfarin therapy (adjusted odds ratio [AOR] = 4.28, 95% confidence interval [CI]: 1.01-18.22). Those living with family had a 56% lower chance of poor warfarin adherence (AOR: 0.44; 95% CI: 0.21-0.93) than those living alone. This study shows room for improvement in patient knowledge, adherence, and satisfaction with warfarin therapy.

Social App to Improve Warfarin Therapy in Post-MHVR Chinese Patients: A Randomized Controlled Trial

Background

Poor anticoagulation quality was a major problem among warfarin-treated patients, which called for innovative and effective methods to improve it.

Objective

To investigate whether social app could be used to reduce warfarin-associated adverse events among post-MHVR Chinese patients.

Method

735 warfarin-treated patients (aged 50.8 ± 9.6 years, 59.9% female) were enrolled and randomized to a social app care group (warfarin therapy was guided by experienced clinicians via a social app) or a routine care group (warfarin therapy was managed through traditional in-office visits) at a 1 : 1 ratio. Ending points (bleeding and thrombotic events) were recorded during an 18-month follow-up period.

Results

A total of 718 patients were included in analysis. 57 of them suffered warfarin-associated adverse events, including 30 major bleedings and 27 thrombotic events. The time in the therapeutic range (TTR, Rosendaal method) in the social app group was 71.5%, which was significantly better than 52.6% in the routine care group (difference: 18.8%, 95% CI: 16.8-20.8). Compared with the patients from the social app group, patients under routine care experienced more bleeding (hazard ratio (HR): 2.31, 95% CI: 1.13-4.72). The social app care group had lower variation (0.55 vs. 0.70) in the international normalized ratio (INR) values and fewer incidents of extremely high INR (e.g., INR > 5.0, 0.87% vs. 3.42%) than the routine care group.

Conclusions

Social app management could significantly improve warfarin control and was associated with a reduction in bleeding risk. This trial was registered with NCT03264937.

Assessment of an Intervention to Reduce Aspirin Prescribing for Patients Receiving Warfarin for Anticoagulation

IMPORTANCE

For some patients receiving warfarin, adding aspirin (acetylsalicylic acid) increases bleeding risk with unclear treatment benefit. Reducing excess aspirin use could be associated with improved clinical outcomes.

OBJECTIVE

To assess changes in aspirin use, bleeding, and thrombosis event rates among patients treated with warfarin.

DESIGN, SETTING, AND PARTICIPANTS

This pre-post observational quality improvement study was conducted from January 1, 2010, to December 31, 2019, at a 6-center quality improvement collaborative in Michigan among 6738 adults taking warfarin for atrial fibrillation and/or venous thromboembolism without an apparent indication for concomitant aspirin. Statistical analysis was conducted from November 26, 2020, to June 14, 2021.

INTERVENTION

Primary care professionals for patients taking aspirin were asked whether an ongoing combination aspirin and warfarin treatment was indicated. If not, then aspirin was discontinued with the approval of the managing clinician.

MAIN OUTCOMES AND MEASURES

Outcomes were assessed before and after intervention for the primary analysis and before and after 24 months before the intervention (when rates of aspirin use first began to decrease) for the secondary analysis. Outcomes included the rate of aspirin use, bleeding, and thrombotic outcomes. An interrupted time series analysis assessed cumulative monthly event rates over time.

RESULTS

A total of 6738 patients treated with warfarin (3160 men [46.9%]; mean [SD] age, 62.8 [16.2] years) were followed up for a median of 6.7 months (IQR, 3.2-19.3 months). Aspirin use decreased slightly from a baseline mean use of 29.4% (95% CI, 28.9%-29.9%) to 27.1% (95% CI, 26.1%-28.0%) during the 24 months before the intervention (P < .001 for slope before and after 24 months before the intervention) with an accelerated decrease after the intervention (mean aspirin use, 15.7%; 95% CI, 14.8%-16.8%; P = .001 for slope before and after intervention). In the primary analysis, the intervention was associated with a significant decrease in major bleeding events per month (preintervention, 0.31%; 95% CI, 0.27%-0.34%; postintervention, 0.21%; 95% CI, 0.14%-0.28%; P = .03 for difference in slope before and after intervention). No change was observed in mean percentage of patients having a thrombotic event from before to after the intervention (0.21% vs 0.24%; P = .34 for difference in slope). In the secondary analysis, reducing aspirin use (starting 24 months before the intervention) was associated with decreases in mean percentage of patients having any bleeding event (2.3% vs 1.5%; P = .02 for change in slope before and after 24 months before the intervention), mean percentage of patients having a major bleeding event (0.31% vs 0.25%; P = .001 for change in slope before and after 24 months before the intervention), and mean percentage of patients with an emergency department visit for bleeding (0.99% vs 0.67%; P = .04 for change in slope before and after 24 months before the intervention), with no change in mean percentage of patients with a thrombotic event (0.20% vs 0.23%; P = .36 for change in slope before and after 24 months before the intervention).

CONCLUSIONS AND RELEVANCE

This quality improvement intervention was associated with an acceleration of a preexisting decrease in aspirin use among patients taking warfarin for atrial fibrillation and/or venous thromboembolism without a clear indication for aspirin therapy. Reductions in aspirin use were associated with reduced bleeding. This study suggests that an anticoagulation clinic-based aspirin deimplementation intervention can improve guideline-concordant aspirin use.

Warfarin Monitoring in Safety-Net Health Systems: Analysis by Race/Ethnicity and Language Preference

BACKGROUND

Racial/ethnic disparities in anticoagulation management are well established. Differences in warfarin monitoring can contribute to these disparities and should be measured.

OBJECTIVE

We assessed for differences in international normalized ratio (INR) monitoring by race/ethnicity and language preference across safety-net care systems serving predominantly low-income, ethnically diverse populations.

DESIGN

Cross-sectional analysis of process and safety data shared from the Safety Promotion Action Research and Knowledge Network (SPARK-Net) initiative, a consortium of five California safety-net hospital systems.

PARTICIPANTS

Eligible patients were at least 18 years old, received warfarin for at least 56 days during the measurement period from July 2015 to June 2017, and had INR testing in an ambulatory care setting at a participating healthcare system.

MAIN MEASURES

We conducted a scaled Poisson regression for adjusted rate ratio of having at least one INR checked per 56-day time period for which a patient had a warfarin prescription. Adjusting for age, sex, healthcare system, and insurance status/type, we assessed for racial/ethnic and language disparities in INR monitoring.

KEY RESULTS

Of 8129 patients, 3615 (44%) were female; 1470 (18%), Black/African American; 3354 (41%), Hispanic/Latinx; 1210 (15%), Asian; 1643 (20%), White; and 452 (6%), other. Three thousand five hundred forty-nine (45%) were non-English preferring. We did not observe statistically significant disparities in the rate of appropriate INR monitoring by race/ethnicity or language; the primary source of variation was by healthcare network. Older age, female gender, and uninsured patients had a slightly higher rate of appropriate INR monitoring, but differences were not clinically significant.

CONCLUSIONS

We did not find a race/ethnicity nor language disparity in INR monitoring; safety-net site was the main source of variation.

Comparison of Warfarin Initiation at 3 mg Versus 5 mg for Anticoagulation of Patients with Mechanical Mitral Valve Replacement Surgery: A Prospective Randomized Trial

Background

The increased warfarin sensitivity observed after mechanical mitral valve replacement (MVR) operations dictates clinical discretion in warfarin dose initiation. Evidence is still lacking with regard to anticoagulation management of MVR patients.

Objective

This study aimed to compare initiating warfarin at the recommended dosing regimen versus empirically lowered doses intended to account for the variation in warfarin sensitivity.

Methods

A prospective, single-blind, randomized, comparative study was conducted in postoperative MVR patients. Patients were randomly assigned to either the 5 mg group (n = 25) or the 3 mg group (n = 25) and were initiated on a 5 or 3 mg warfarin dose, respectively. Time to target international normalized ratio (INR), time in therapeutic range, occurrence of bleeding/thromboembolic events, and cost of bridging with enoxaparin were assessed for both groups.

Results

Target INR was achieved earlier in the 5 mg group than in the 3 mg group (p = 0.033), with a mean ± SD of 5.3 ± 2.0 and 6.6 ± 2.0, respectively (95% confidence interval of the mean difference 1.022–1.890). Bleeding events did not differ significantly between the two groups. The cost of enoxaparin consumption per patient was significantly higher in the 3 mg group versus the 5 mg group (p = 0.002).

Conclusions

The initiation of warfarin at a 5 mg dose in MVR patients was more efficacious than the 3 mg dose in terms of time to reach the target INR. Moreover, the cost of enoxaparin bridging was significantly reduced with a 5 mg warfarin initiation dose. Bleeding events were comparable.

ClinicalTrials.gov ID

NCT04235569, 22 January 2020.

Management Strategies Following Slightly Out of Range INRs: Watchful Waiting vs. Dose Changes

Watchful waiting describes maintaining a warfarin dose after a slightly out-of-range INR and retesting within the following 2 weeks.

Although a warfarin dose change is more effective in producing a therapeutic INR, our study supports ACCP guidelines for watchful waiting.

Patients’ international normalized ratios (INRs) often fall slightly out of range. In these cases, the American College of Chest Physicians (ACCP) guidelines suggest maintaining the current warfarin dose and retesting the INR within the following 2 weeks (watchful waiting). We sought to determine whether watchful waiting or dose changes for slightly out-of-range INRs is more effective in obtaining in-range INRs at follow-up. INRs and management strategies of warfarin-treated patients within the Michigan Anticoagulation Quality Improvement Initiative registry were analyzed. Management strategies included watchful waiting or dose changes. INRs slightly out of range (target range 2.0-3.0) and their associated management were identified. Multilevel mixed-effects logistic regression was used to estimate the probability of the next INR being in range, adjusted for clustering due to multiple out-of-range INRs per patient. A total of 45 351 slightly out-of-range INRs (ranging 1.50-1.99 and 3.01-3.49) from 8288 patients were identified. The next INR was slightly less likely to be in range with watchful waiting than with a dose change (predicted probabilities 58.9% vs 60.0%, P = 0.024). Although a significant statistical difference was detected in the probabilities of the next INR being back in range when managed by a dose change compared with watchful waiting following a slightly out-of-range INR, the magnitude of the difference was small and unlikely to represent clinical importance. Our study supports the current guideline recommendations for watchful waiting in cases of slightly out-of-range INRs values.

Adverse Events Associated With the Addition of Aspirin to Direct Oral Anticoagulant Therapy Without a Clear Indication

IMPORTANCE

It is unclear how many patients treated with a direct oral anticoagulant (DOAC) are using concomitant acetylsalicylic acid (ASA, or aspirin) and how this affects clinical outcomes.

OBJECTIVE

To evaluate the frequency and outcomes of prescription of concomitant ASA and DOAC therapy for patients with atrial fibrillation (AF) or venous thromboembolic disease (VTE).

DESIGN, SETTING, AND PARTICIPANTS

This registry-based cohort study took place at 4 anticoagulation clinics in Michigan from January 2015 to December 2019. Eligible participants were adults undergoing treatment with a DOAC for AF or VTE, without a recent myocardial infarction (MI) or history of heart valve replacement, with at least 3 months of follow-up.

EXPOSURES

Use of ASA concomitant with DOAC therapy.

MAIN OUTCOMES AND MEASURES

Rates of bleeding (any, nonmajor, major), rates of thrombosis (stroke, VTE, MI), emergency department visits, hospitalizations, and death.

RESULTS

Of the study cohort of 3280 patients (1673 [51.0%] men; mean [SD] age 68.2 [13.3] years), 1107 (33.8%) patients without a clear indication for ASA were being treated with DOACs and ASA. Two propensity score-matched cohorts, each with 1047 patients, were analyzed (DOAC plus ASA and DOAC only). Patients were followed up for a mean (SD) of 20.9 (19.0) months. Patients taking DOAC and ASA experienced more bleeding events compared with DOAC monotherapy (26.0 bleeds vs 31.6 bleeds per 100 patient years, P = .01). Specifically, patients undergoing combination therapy had significantly higher rates of nonmajor bleeding (26.1 bleeds vs 21.7 bleeds per 100 patient years, P = .02) compared with DOAC monotherapy. Major bleeding rates were similar between the 2 cohorts. Thrombotic event rates were also similar between the cohorts (2.5 events vs 2.3 events per 100 patient years for patients treated with DOAC and ASA compared with DOAC monotherapy, P = .80). Patients were more often hospitalized while undergoing combination therapy (9.1 vs 6.5 admissions per 100 patient years, P = .02).

CONCLUSION AND RELEVANCE

Nearly one-third of patients with AF and/or VTE who were treated with a DOAC received ASA without a clear indication. Compared with DOAC monotherapy, concurrent DOAC and ASA use was associated with increased bleeding and hospitalizations but similar observed thrombosis rate. Future research should identify and deprescribe ASA for patients when the risk exceeds the anticipated benefit.

Budget Impact Analysis of Anticoagulation Clinics in Patients with Atrial Fibrillation under Chronic Therapy with Oral Anticoagulants

OBJECTIVES

To assess budget impact of the implementation of an anticoagulation clinic (AC) compared to usual care (UC), in patients with non-valvular atrial fibrillation (NVAF).

METHOD

A decision tree was designed to analyze the cost and events rates over a 1-year horizon. The patients were distributed according to treatment, 30% Direct Oral Anticoagulant (DOAC) regimens and the rest to warfarin. The thromboembolism and bleeding were derived from observational studies which demonstrated that ACs had important impact in reducing the frequency of these events compared with UC, due to higher adherence with DOACs and proportion of time in therapeutic range (TTR) with warfarin. Costs were derived from the transactional platform of Colombian government, healthcare authority reimbursement and published studies. The values were expressed in American dollars (USD). The exchanged rate used was COP $3.693 per dollar.

RESULTS

During 1 year of follow-up, in a cohort of 228 patients there were estimated 48 bleedings, 6 thromboembolisms in AC group versus 84 bleedings, and 12 thromboembolisms events in patients receiving UC. Total costs related to AC were $126 522 compared with $141 514 in UC. The AC had an important reduction in the cost of clinical events versus UC ($52 085 vs $110 749) despite a higher cost of care facilities ($74 436 vs $30 765). A sensibility analysis suggested that in the 83% of estimations, the AC produced savings varied between $27 078 and $135 391.

CONCLUSIONS

This study demonstrated that AC compared with UC, produced an important savings in the oral anticoagulation therapy for patients with NVAF.

Reduction in epistaxis and emergency department visits in patients taking warfarin after implementation of an education program

BACKGROUND

Anticoagulated patients are often seen unnecessarily in the emergency department (ED) for epistaxis, leading to increased healthcare costs. Patients are often unaware of preventative and management techniques for handling epistaxis in the home.

METHODS

In 2016, the Michigan Anticoagulation Quality Improvement Initiative (MAQI²), a Blue Cross Blue Shield of Michigan-sponsored consortium of 6 anticoagulation clinics in Michigan, implemented an epistaxis-management educational program for warfarin-treated patients with the goal of reducing unnecessary ED visits. A pre-implementation cohort (2014-2015) consisted of patients who did not receive epistaxis-related educational materials. A post-implementation cohort (2017-2018) received epistaxis educational materials covering home treatment and prevention strategies. Patient characteristics and outcomes (rates of epistaxis and epistaxis ED visits) were compared using Chi-square, Poisson regression, and t-tests.

RESULTS

Of the 4473 patients included, 2634 (58.9%) initiated warfarin in the pre-implementation phase and 1839 (41.1%) initiated warfarin in the post-implementation phase. The post-implementation cohort had a lower overall epistaxis rate (13.4 vs 10.4 per 100 patient-year, pre- vs. post-implementation; p = 0.029), a lower epistaxis-related ED visit rate (5.6 vs. 3.1 per 100 patient-year; p = 0.003), and a lower proportion of nosebleeds that led to an ED visit (42% vs. 30%; p = 0.032). After controlling for antiplatelet use, renal disease, and time in therapeutic range, both cohorts were equally likely to have nosebleeds (RR 0.77, 95% CI: 0.58-1.02); however, the post-implementation cohort was less likely to visit the ED for epistaxis (RR 0.52, 95% CI: 0.32-0.84).

CONCLUSION

An epistaxis education program was associated with a reduction in epistaxis-related ED visits among warfarin-treated patients.

Periprocedural bridging anticoagulation in patients with venous thromboembolism: A registry-based cohort study

BACKGROUND

Use of bridging anticoagulation increases a patient's bleeding risk without clear evidence of thrombotic prevention among warfarin-treated patients with atrial fibrillation. Contemporary use of bridging anticoagulation among warfarin-treated patients with venous thromboembolism (VTE) has not been studied.

METHODS

We identified warfarin-treated patients with VTE who temporarily stopped warfarin for a surgical procedure between 2010 and 2018 at six health systems. Using the 2012 American College of Chest Physicians guideline, we assessed use of periprocedural bridging anticoagulation based on recurrent VTE risk. Recurrent VTE risk and 30-day outcomes (bleeding, thromboembolism, emergency department visit) were each assessed using logistic regression adjusted for multiple procedures per patient.

RESULTS

During the study period, 789 warfarin-treated patients with VTE underwent 1529 procedures (median, 2; interquartile range, 1-4). Unadjusted use of bridging anticoagulation was more common in patients at high risk for VTE recurrence (99/171, 57.9%) than for patients at moderate (515/1078, 47.8%) or low risk of recurrence (134/280, 47.86%). Bridging anticoagulation use was higher in high-risk patients compared with low- or moderate-risk patients in both unadjusted (P = .013) and patient-level cluster-adjusted analyses (P = .031). Adherence to American College of Chest Physicians guidelines in high- and low-risk patients did not change during the study period (odds ratio, 0.98 per year; 95% confidence interval, 0.91-1.05). Adverse events were rare and not statistically different between the two treatment groups.

CONCLUSIONS

Bridging anticoagulation was commonly overused among low-risk patients and underused among high-risk patients treated with warfarin for VTE. Adverse events were rare and not different between the two treatment groups.

How reliable is perioperative anticoagulant management? Determining guideline compliance and practice variation by a retrospective patient record review

OBJECTIVES

Surgery in patients on anticoagulants requires careful monitoring and risk assessment to prevent harm. Required interruptions of anticoagulants and deciding whether to use bridging anticoagulation add further complexity. This process, known as perioperative anticoagulant management (PAM), is optimised by using guidelines. Optimal PAM prevents thromboembolic and bleeding complications. The purpose of this study was to assess the reliability of PAM practice in Dutch hospitals. Additionally, the variations between hospitals and different bridging dosages were studied.

DESIGN

A multicentre retrospective patient record review.

SETTING AND PARTICIPANTS

Records from 268 patients using vitamin-K antagonist (VKA) anticoagulants who underwent surgery in a representative random sample of 13 Dutch hospitals were reviewed, 259 were analysed.

PRIMARY AND SECONDARY OUTCOME MEASURES

Our primary outcome measure was the reliability of PAM expressed as the percentage of patients receiving guideline compliant care. Seven PAM steps were included. Secondary outcome measures included different bridging dosages used and an analysis of practice variation on the hospital level.

RESULTS

Preoperative compliance was lowest for timely VKA interruptions: 58.8% (95% CI 50.0% to 67.7%) and highest for timely preoperative assessments: 81% (95% CI 75.0% to 86.5%). Postoperative compliance was lowest for timely VKA restarts: 39.9% (95% CI 33.1% to 46.7%) and highest for the decision to apply bridging: 68.5% (95% CI 62.3% to 74.8%). Variation in compliance between hospitals was present for the timely preoperative assessment (range 41%-100%), international normalised ratio testing (range 21%-94%) and postoperative bridging (range 20%-88%). Subtherapeutic bridging was used in 50.5% of patients and increased with patients' weight.

CONCLUSIONS

Unsatisfying compliance for most PAM steps, reflect suboptimal reliability of PAM. Furthermore, the hospital performance varied. This increases the risk for adverse events, warranting quality improvement. The development of process measures can help but will be complicated by the availability of a strong supporting evidence base and integrated care delivery regarding PAM.

Association of Adding Aspirin to Warfarin Therapy Without an Apparent Indication With Bleeding and Other Adverse Events

IMPORTANCE

It is not clear how often patients receive aspirin (acetylsalicylic acid) while receiving oral anticoagulation with warfarin sodium without a clear therapeutic indication for aspirin, such as a mechanical heart valve replacement, recent percutaneous coronary intervention, or acute coronary syndrome. The clinical outcomes of such patients treated with warfarin and aspirin therapy compared with warfarin monotherapy are not well defined to date.

OBJECTIVE

To evaluate the frequency and outcomes of adding aspirin to warfarin for patients without a clear therapeutic indication for combination therapy.

DESIGN, SETTING, AND PARTICIPANTS

A registry-based cohort study of adults enrolled at 6 anticoagulation clinics in Michigan (January 1, 2010, to December 31, 2017) who were receiving warfarin therapy for atrial fibrillation or venous thromboembolism without documentation of a recent myocardial infarction or history of valve replacement.

EXPOSURE

Aspirin use without therapeutic indication.

MAIN OUTCOMES AND MEASURES

Rates of any bleeding, major bleeding events, emergency department visits, hospitalizations, and thrombotic events at 1, 2, and 3 years.

RESULTS

Of the study cohort of 6539 patients (3326 men [50.9%]; mean [SD] age, 66.1 [15.5] years), 2453 patients (37.5%) without a clear therapeutic indication for aspirin were receiving combination warfarin and aspirin therapy. Data from 2 propensity score-matched cohorts of 1844 patients were analyzed (warfarin and aspirin vs warfarin only). At 1 year, patients receiving combination warfarin and aspirin compared with those receiving warfarin only had higher rates of overall bleeding (cumulative incidence, 26.0%; 95% CI, 23.8%-28.3% vs 20.3%; 95% CI, 18.3%-22.3%; P < .001), major bleeding (5.7%; 95% CI, 4.6%-7.1% vs 3.3%; 95% CI, 2.4%-4.3%; P < .001), emergency department visits for bleeding (13.3%; 95% CI, 11.6%-15.1% vs 9.8%; 95% CI, 8.4%-11.4%; P = .001), and hospitalizations for bleeding (8.1%; 6.8%-9.6% vs 5.2%; 4.1%-6.4%; P = .001). Rates of thrombosis were similar, with a 1-year cumulative incidence of 2.3% (95% CI, 1.6%-3.1%) for those receiving combination warfarin and aspirin therapy compared with 2.7% (95% CI, 2.0%-3.6%) for those receiving warfarin alone (P = .40). Similar findings persisted during 3 years of follow-up as well as in sensitivity analyses.

CONCLUSIONS AND RELEVANCE

Compared with warfarin monotherapy, receipt of combination warfarin and aspirin therapy was associated with increased bleeding and similar observed rates of thrombosis. Further research is needed to better stratify which patients may benefit from aspirin while anticoagulated with warfarin for atrial fibrillation or venous thromboembolism; clinicians should be judicious in selecting patients for combination therapy.

Development of Quality Indicators to Assess Oral Anticoagulant Management in Community Pharmacies for Patients with Atrial Fibrillation

BACKGROUND

Few studies have evaluated the quality of oral anticoagulant management by community pharmacists. There is no complete set of quality indicators available for this purpose.

OBJECTIVE

To develop a set of specific quality indicators to assess oral anticoagulant management by community pharmacists for patients with atrial fibrillation (AF).

METHODS

Quality indicators were developed in 3 phases. In phase 1, potential quality indicators were generated based on clinical guidelines and a literature review. In phase 2, a modified RAND appropriateness method involving 2 rounds was implemented with 9 experts, who judged the appropriateness of quality indicators generated in phase 1 based on the extent to which they were accurate, based on evidence, relevant, representative of best practices, and measurable in community pharmacies. Phase 3 consisted of a feasibility assessment in 5 community pharmacies on 2 patients each.

RESULTS

The final set included 38 quality indicators grouped into 6 categories: documentation (n = 29), risk assessment (n = 3), clinical control (n = 1), clinical follow-up (n = 15), choice of therapy (n = 11), and interaction management (n = 8). The quality indicators referred to process of care (n = 34), clinical outcomes (n = 2), or structure of care (n = 2). There were 24 quality indicators related to vitamin K antagonists (VKAs), and 17 were related to direct oral anticoagulants (DOACs). To assess quality indicators, a questionnaire was developed for completion by community pharmacists for each patient, which included 17 questions about VKA patients and 12 questions about DOAC patients.

CONCLUSIONS

A first set of quality indicators is now available to assess the quality of oral anticoagulant management by community pharmacists for patients with AF.

DISCLOSURES

This research was supported by the Réseau Québécois de recherche sur le médicament (RQRM); the Blueprint for Pharmacy in collaboration with Pfizer Canada; and the Cercle du Doyen of the Faculty of Pharmacy, University of Montreal. The study sponsors were not involved in the study design, data collection, data interpretation, the writing of the article, or the decision to submit the report for publication. Chartrand received a scholarship from the Fonds de Recherche du Québec en Santé (FRQ-S), the Réseau Québécois de recherche sur l'usage des médicaments with Pfizer, and the Faculty of Pharmacy, University of Montreal. Guénette holds a Junior-1 Clinician Researcher Award from the FRQ-S in partnership with the Société québécoise d'hypertension artérielle. Williamson holds a Junior-1 Career Award from the FRQ-S. Côté reported being a medical speaker for Bayer, Boehringer Ingelheim Canada, and Pfizer Canada. The other authors reported no conflicts of interest. Study concept and design were contributed by Lalonde, Chartrand, and Martin. Chartrand, Martin, and Lalonde collected the data, along with Brouillette, Côté, Huot, Landry, Martineau, Perreault, Williamson, and White-Guay. Data interpretation was performed by Chartrand, Gagnon, and Lalonde, along with Guénette and Martin. The manuscript was primarily written by Chartrand, along with Guénette and Lalonde, and revised by Chartrand, Guénette, and Lalonde, along with the other authors. A portion of this study's results was presented at the 4th RQRM Annual Meeting on September 22-23, 2014, in Orford, Quebec, Canada, in the form of an abstract, which was published in the Journal of Population Therapeutics and Clinical Pharmacology, 2014;21(2):e312.

Sociodemographic factors in patients continuing warfarin vs those transitioning to direct oral anticoagulants

Clinical factors and patient preferences are important for selecting oral anticoagulants for venous thromboembolism (VTE) and atrial fibrillation (AF). The relative association of sociodemographic factors with anticoagulant use is unknown. We evaluated a prospective cohort to compare sociodemographic variables in patients who continued on warfarin for AF or VTE to those who transitioned to 1 of the direct oral anticoagulants (DOACs). Adult patients, newly started on warfarin, were enrolled through 6 anticoagulation clinics across Michigan. Of 8468 patients, 53.3% had AF, 45.6% had VTE, and 1.1% had both. Of these, 696 (8.2%) switched from warfarin to a DOAC. There were no significant differences between switchers and nonswitchers for percentage of time with a therapeutic international normalized ratio on warfarin, urban-rural residence status, or health insurance. Switchers were more often white (83.3% vs 77.7%; P < .001), partnered (67.3% vs 59.2%; P < .001), or resided in a zip code with a higher median household income (P < .001). The results show that sociodemographic factors, such as race, partnered status, and income are associated with a patient's likelihood of switching to a DOAC vs remaining on warfarin therapy. Although clinical factors predominate, the reason for, and impact of, these observed variations in care requires further investigation.

Barriers and facilitators to reducing frequent laboratory testing for patients who are stable on warfarin: a mixed methods study of de-implementation in five anticoagulation clinics

Background

Patients on chronic warfarin therapy require regular laboratory monitoring to safely manage warfarin. Recent studies have challenged the need for routine monthly blood draws in the most stable warfarin-treated patients, suggesting the safety of less frequent laboratory testing (up to every 12 weeks). De-implementation efforts aim to reduce the use of low-value clinical practices. To explore barriers and facilitators of a de-implementation effort to reduce the use of frequent laboratory tests for patients with stable warfarin management in nurse/pharmacist-run anticoagulation clinics, we performed a mixed-methods study conducted within a state-wide collaborative quality improvement collaborative.

Methods

Using a mixed-methods approach, we conducted post-implementation semi-structured interviews with a total of eight anticoagulation nurse or pharmacist staff members at five participating clinic sites to assess barriers and facilitators to de-implementing frequent international normalized ratio (INR) laboratory testing among patients with stable warfarin control. Interview guides were based on the Tailored Implementation for Chronic Disease (TICD) framework. Informed by interview themes, a survey was developed and administered to all anticoagulation clinical staff (n = 62) about their self-reported utilization of less frequent INR testing and specific barriers to de-implementing the standard (more frequent) INR testing practice.

Results

From the interviews, four themes emerged congruent with TICD domains: (1) staff overestimating their actual use of less frequent INR testing (individual health professional factors), (2) barriers to appropriate patient engagement (incentives and resources), (3) broad support for an electronic medical record flag to identify potentially eligible patients (incentives and resources), and (4) the importance of personalized nurse/pharmacist feedback (individual health professional factors). In the survey (65% response rate), staff report offering less frequent INR testing to 56% (46–66%) of eligible patients. Most survey responders (n = 24; 60%) agreed that an eligibility flag in the electronic medical record would be very helpful. Twenty-four (60%) respondents agreed that periodic, personalized feedback on use of less frequent INR testing would also be helpful.

Conclusions

Leveraging information system notifications, reducing additional work load burden for participating patients and providers, and providing personalized feedback are strategies that may improve adoption and utilization new policies in anticoagulation clinics that focus on de-implementation.

Electronic supplementary material

The online version of this article (doi:10.1186/s13012-017-0620-x) contains supplementary material, which is available to authorized users.