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

Differences in quality of anticoagulation care delivery according to ethnoracial group in the United States: A scoping review

Anticoagulation therapy is standard for conditions like atrial fibrillation, venous thromboembolism, and valvular heart disease, yet it is unclear if there are ethnoracial disparities in its quality and delivery in the United States. For this scoping review, electronic databases were searched for publications between January 1, 2011 - March 30, 2022. Eligible studies included all study designs, any setting within the United States, patients prescribed anticoagulation for any indication, outcomes reported for ≥ 2 distinct ethnoracial groups. The following four research questions were explored: Do ethnoracial differences exist in 1) access to guideline-based anticoagulation therapy, 2) quality of anticoagulation therapy management, 3) clinical outcomes related to anticoagulation care, 4) humanistic/educational outcomes related to anticoagulation therapy. A total of 5374 studies were screened, 570 studies received full-text review, and 96 studies were analyzed. The largest mapped focus was patients' access to guideline-based anticoagulation therapy (88/96 articles, 91.7%). Seventy-eight articles made statistical outcomes comparisons among ethnoracial groups. Across all four research questions, 79 articles demonstrated favorable outcomes for White patients compared to non-White patients, 38 articles showed no difference between White and non-White groups, and 8 favored non-White groups (the total exceeds the 78 articles with statistical outcomes as many articles reported multiple outcomes). Disparities disadvantaging non-White patients were most pronounced in access to guideline-based anticoagulation therapy (43/66 articles analyzed) and quality of anticoagulation management (19/21 articles analyzed). Although treatment guidelines do not differentiate anticoagulant therapy by ethnoracial group, this scoping review found consistently favorable outcomes for White patients over non-White patients in the domains of access to anticoagulation therapy for guideline-based indications and quality of anticoagulation therapy management. No differences among groups were noted in clinical outcomes, and very few studies assessed humanistic or educational outcomes.

Prescription and switching patterns of direct oral anticoagulants in patients with atrial fibrillation

Background

The patterns of direct oral anticoagulant (DOAC) selection and switching to a different oral anticoagulant (OAC) in patients with atrial fibrillation (AF) are unknown.

Objectives

To describe temporal patterns in first DOAC prescriptions, estimate the incidence, and identify predictors of switching to a different OAC within 1 year in OAC-naive AF patients.

Methods

In this retrospective cohort study, using a near-nationwide prescription registry (IQVIA, the Netherlands), we determined the number of patients per month initiated on each DOAC and identified predictors of switching within 1 year with robust Poisson regression.

Results

We included 94,874 patients. From November 2015 to November 2019, the monthly use of apixaban (n = 366 to n = 1066, +191%), rivaroxaban (n = 379 to n = 868, +129%), and edoxaban (n = 2 to n = 305, +15,150%) increased, whereas that of dabigatran decreased (n = 317 to n = 179, -44%). In the 66,090 patients with ≥1 year of available calendar time, 7% switched to a different OAC within 1 year. Strong predictors of switching to a different DOAC were using dabigatran (adjusted risk ratio [aRR], 3.33; 95% CI, 3.02-3.66) or edoxaban (aRR, 1.56; 95% CI, 1.34-1.82) rather than apixaban and using a standard DOAC dose (aRR, 2.54; 95% CI, 2.23-2.88). Strong predictors of switching to a vitamin K antagonist were using rivaroxaban (aRR, 1.36; 95% CI, 1.19-1.54 vs apixaban) and using a standard DOAC dose (aRR, 1.49; 95% CI, 1.26-1.77).

Conclusion

In the Netherlands, factor Xa inhibitors are increasingly being selected for OAC-naive AF patients. Seven percent of patients switch to a different OAC within 1 year, and the initial DOAC type and dose are strong predictors of switching.

Frequency and clinical outcomes of pharmacist-driven switching from warfarin to direct oral anticoagulants in an underserved patient population: A retrospective cohort study

PURPOSE

Direct oral anticoagulant (DOAC) medications have improved safety, efficacy, and laboratory monitoring requirements compared to warfarin. However, available data are limited on the frequency and clinical outcomes of pharmacist-driven warfarin-to-DOAC switches. We aimed to quantify the frequencies and rationale of warfarin-to-DOAC switches in an underserved population. We also assessed clinical outcomes and compliance with recommended laboratory monitoring after switches.

METHODS

This retrospective cohort study included adult (age 18 years or older) patients on warfarin who were assessed by a clinical pharmacist for switch appropriateness to a DOAC. Study data were collected via manual chart review and included demographics, comorbid illnesses, switch status, the rationale for or against switching, incidence of thromboses and bleeds within 6 months of the switch assessment, and the time to the first complete blood count and renal and hepatic function tests after the switch. Statistical analysis utilized descriptive statistics, including the mean and SD, median and interquartile range, and frequencies and percentages.

RESULTS

Among 189 eligible patients, 108 (57%) were switched from warfarin to a DOAC. The primary rationales for switching were less monitoring (64%) and labile international normalized ratio (32%). The main reason against switching was DOAC inappropriateness (53%), such as in morbid obesity (14%). Patient preference was commonly cited in both groups (54% and 36%, respectively). The overall incidence of thrombotic events (9%) and bleeds (15%) after switch assessment was low. Laboratory monitoring after switches was consistent with current recommendations.

CONCLUSION

No increase in harm was observed 6 months after switch assessment when pharmacists at a family medicine clinic switched underserved patients from warfarin to DOACs.

Association of Race and Ethnicity With Oral Anticoagulation and Associated Outcomes in Patients With Atrial Fibrillation: Findings From the Get With The Guidelines-Atrial Fibrillation Registry

Importance

Oral anticoagulation (OAC) is underprescribed in underrepresented racial and ethnic group individuals with atrial fibrillation (AF). Little is known of how differential OAC prescribing relates to inequities in AF outcomes.

Objective

To compare OAC use at discharge and AF-related outcomes by race and ethnicity in the Get With The Guidelines-Atrial Fibrillation (GWTG-AFIB) registry.

Design, Setting, and Participants

This retrospective cohort analysis used data from the GWTG-AFIB registry, a national quality improvement initiative for hospitalized patients with AF. All registry patients hospitalized with AF from 2014 to 2020 were included in the study. Data were analyzed from November 2021 to July 2022.

Exposures

Self-reported race and ethnicity assessed in GWTG-AFIB registry.

Main Outcomes and Measures

The primary outcome was prescription of direct-acting OAC (DOAC) or warfarin at discharge. Secondary outcomes included cumulative 1-year incidence of ischemic stroke, major bleeding, and mortality postdischarge. Outcomes adjusted for patient demographic, clinical, and socioeconomic characteristics as well as hospital factors.

Results

Among 69 553 patients hospitalized with AF from 159 sites between 2014 and 2020, 863 (1.2%) were Asian, 5062 (7.3%) were Black, 4058 (5.8%) were Hispanic, and 59 570 (85.6%) were White. Overall, 34 113 (49.1%) were women; the median (IQR) age was 72 (63-80) years, and the median (IQR) CHA2DS2-VASc score (calculated as congestive heart failure, hypertension, age 75 years and older, diabetes, stroke or transient ischemic attack, vascular disease, age 65 to 74 years, and sex category) was 4 (2-5). At discharge, 56 385 patients (81.1%) were prescribed OAC therapy, including 41 760 (74.1%) receiving DOAC. OAC prescription at discharge was lowest in Hispanic patients (3010 [74.2%]), followed by Black patients (3935 [77.7%]) Asian patients (691 [80.1%]), and White patients (48 749 [81.8%]). Black patients were less likely than White patients to be discharged while taking any anticoagulant (adjusted odds ratio, 0.75; 95% CI, 0.68-0.84) and DOACs (adjusted odds ratio, 0.73; 95% CI, 0.65-0.82). In 16 307 individuals with 1-year follow up data, bleeding risks (adjusted hazard ratio [aHR], 2.08; 95% CI, 1.53-2.83), stroke risks (aHR, 2.07; 95% CI, 1.34-3.20), and mortality risks (aHR, 1.22; 95% CI, 1.02-1.47) were higher in Black patients than White patients. Hispanic patients had higher stroke risk (aHR, 2.02; 95% CI, 1.38-2.95) than White patients.

Conclusions and Relevance

In a national registry of hospitalized patients with AF, compared with White patients, Black patients were less likely to be discharged while taking anticoagulant therapy and DOACs in particular. Black and Hispanic patients had higher risk of stroke compared with White patients; Black patients had a higher risk of bleeding and mortality. There is an urgent need for interventions to achieve pharmacoequity in guideline-directed AF management to improve overall outcomes.

Choice of oral anticoagulant prescribed by general practices in Wales: Application of Dirichlet regression and linked data

Aims

There has been sustained growth in the prescribing of direct oral anticoagulants (OACs) in primary care in the UK. Given the different indications, properties and prices of OACs, variation between prescribers is expected; however, a high level of variation may be evidence of inappropriate or suboptimal prescribing. This study examined the variation in the relative use of OACs in primary care in Wales.

Methods

Data on total defined daily doses of all community‐dispensed OACs in 2019 were linked at the GP practice level with disease registers, patient demographic data and GP and patient numbers. The relative use of each OAC, as a fraction of all OACs prescribed, was analysed using Dirichlet regression to quantify the association between prescribing patterns and practice and area‐level characteristics.

Results

Across 417 GP practices, the mean (range) in the relative prescribing of warfarin was 37% (6%–64%), apixaban was 32% (2%–65%), rivaroxaban 23% (0%–66%), dabigatran 3% (0%–23%) and edoxaban 6% (0%–59%). Statistical modelling provided strong evidence that prescribing patterns are associated with a GP practice's health board and also their nearest major hospital. Compared to the null model, a model including health board resulted in a 15% fall in Akaike information criterion, increasing to 20% with the addition of nearest major hospital and 27% including further covariates.

Conclusion

Systematic variation in OAC prescribing, by health board and based on nearest hospital, indicates that factors other than patient clinical characteristics and preferences may be influencing prescribing decisions.

Factors Influencing the Selection of Non-Vitamin K Antagonist Oral Anticoagulants for Stroke Prevention in Patients With Non-Valvular Atrial Fibrillation

BACKGROUND

Major atrial fibrillation (AF) guidelines recommend non-vitamin K antagonist oral anticoagulants (NOACs) over warfarin, except in rare clinical circumstances based on 4 randomized controlled trials comparing each NOAC with warfarin. We aimed to investigate the current NOAC prescription behaviors in alignment with the recent clinical evidence available.

METHOD

We conducted a cross-sectional analysis of NOAC-using patients with non-valvular atrial fibrillation (NVAF) who were aged ≥65 years on the index date (July 1, 2018) based on nationwide claims data. The types of NOACs being taken were analyzed using chi-squared tests, and factors influencing NOAC selection were identified using multinomial logistic regression analysis.

RESULTS

A total of 6,061 patients were included. Among the 4 NOACs, rivaroxaban was the most used NOAC. Patients aged ≥75 years (odds ratio [OR] = 1.270, confidence interval [CI] = 1.089-1.450) and women (OR = 1.148, CI = 1.011-1.284) were more likely to use apixaban relative to rivaroxaban. Patients with prior stroke/transient ischemic attack/thromboembolism had higher odds of using dabigatran (OR = 1.508, CI = 1.312-1.704) and apixaban (OR = 1.186, CI = 1.026-1.346). Patients with renal disease had higher odds of using apixaban (OR = 1.466, 95% CI = 1.238-1.693). These findings are consistent with the efficacy and safety profiles reported in pivotal trials and observational studies comparing individual NOACs.

CONCLUSION

Among the 4 NOACs, rivaroxaban was the most commonly used NOAC. Apixaban was preferred for patients aged ≥75 years, females, and patients with renal disease.

Meta-Analysis of Safety and Efficacy of Direct Oral Anticoagulants Versus Warfarin According to Time in Therapeutic Range in Atrial Fibrillation

Among atrial fibrillation (AF) patients, it is unclear whether the efficacy and safety of direct oral anticoagulants (DOAC) relative to warfarin is consistent across various levels of international normalized ratio (INR) control. To determine the efficacy and safety of DOAC agents compared with warfarin for patients with various levels of anticoagulation control as reflected by their time in therapeutic range (TTR), we conducted a systematic review and meta-analysis of published randomized controlled trials of DOAC versus (vs) warfarin which reported outcomes stratified by TTR. Based on reported center-based TTR (cTTR) ranges, degrees of INR control were categorized into 3 cTTR strata: low (<60%), intermediate (60% to 66%), and high (>66%). Pooled hazard ratios (HR) and 95% confidence intervals (CI) were determined for stroke or systemic embolism (SSE), major bleeding, and intracranial hemorrhage (ICH). Across all cTTR strata, DOAC-treated patients had lower risk of SSE versus warfarin, with a HR of 0.73 (95% CI 0.61 to 0.88) for the low, 0.76 (95% CI 0.59 to 0.98) intermediate; and 0.78 (95% CI 0.63 to 0.96) high cTTR subgroups. Compared with warfarin, DOAC-treated patients had lower risk of major bleeding in the low and intermediate cTTR strata, and similar risk in the highest cTTR stratum (HR 1.00, 95% CI 0.80 to 1.26). Patients treated with DOAC had lower risk of ICH compared with warfarin (HR 0.55, 95% CI; 0.40 to 0.74) which was observed across all cTTR strata. In conclusion, regardless of the degree of INR control, DOAC agents are preferable over warfarin as stroke prevention therapy for patients with AF.

Factors That Affect Time to Switch From Warfarin to a Direct Oral Anticoagulant After Change in the Reimbursement Criteria in Patients With Atrial Fibrillation

BACKGROUND

Anticoagulation therapy is recommended for stroke prevention in high-risk patients with atrial fibrillation (AF). This study aimed to estimate the time to switch from warfarin to a direct oral anticoagulant (DOAC) and identify the factors associated with it.

METHODS

By using claims data, we studied 7111 warfarin-using patients with nonvalvular AF who were aged ≥65 years. The Kaplan-Meier analysis was performed to estimate the time to switch from warfarin to a DOAC, and Cox proportional hazard regression analysis was used to estimate the influencing factors.

RESULTS

Approximately one-third of the patients (2403, 33.8%) switched from warfarin to a DOAC during the study period. Female sex, aged between 75 and 79 years, having a Medical Aid or Patriots and Veterans Insurance, hypertension, and history of prior stroke, and transient ischemic attack or thromboembolism (prior stroke/TIA/TE) were associated with a significantly shorter time to switch. The odds of switching to a DOAC were increased by approximately 1.2-fold in the women and 1.4-fold in the patients with prior stroke/TIA/TE.

CONCLUSIONS

Approximately one-third of the warfarin-using patients switched from warfarin to a DOAC within 6 months after the change in the DOAC reimbursement criteria. In the Cox proportional hazard regression analysis, the factors that affected anticoagulant switching from warfarin to a DOAC were female sex and history of prior stroke/TIA/TE.