Patients' preferences for new versus old anticoagulants: a mixed-method vignette-based study

Half-dose direct oral anticoagulation versus warfarin for atrial fibrillation following cardiac surgery

BACKGROUND

Optimal anticoagulation strategies have not been defined for patients with atrial fibrillation following cardiac surgery.

METHODS

From a total cohort of 228 patients with pre-existing or new onset atrial fibrillation following coronary artery bypass grafting and/or valve surgery, we compared in-hospital and 30-day outcomes in 119 patients treated with low-dose aspirin and a half-dose direct oral anticoagulant (DOAC) versus 109 treated with low-dose aspirin and warfarin.

RESULTS

DOAC patients were older (73.1±7.0 vs. 68.7±11.4 years, P<0.001) and had a lower incidence of preoperative atrial fibrillation (37 [31.1%] vs. 69 [63.3%], P<0.001). Otherwise, the two cohorts were well matched for baseline demographics, cardiovascular risk factors, comorbidities, prior cardiac history and STS Risk Score. In comparison to Warfarin patients, DOAC patients had a shorter length of post-surgical stay (6 [5-8] vs. 7 [5-10] days, P=0.037). The two cohorts, however, had a similar incidence of stroke, transient ischemic attack, reoperation for bleeding and postoperative blood bank product usage. Follow-up 30-day outcomes did not differ between the two groups with respect to mortality (0 [0.0%] vs. 0 [0.0%], P=1.000) and hospital readmission (16 [13.4%] vs. 14 [12.8%], P=0.893), although two DOAC patients required drainage of sanguineous pericardial effusions.

CONCLUSIONS

In comparison to warfarin, half-dose DOAC anticoagulation in patients with atrial fibrillation following cardiac surgery is associated with a shorter postoperative length of stay, without a significant increase in stroke/transient ischemic attack, reoperation for bleeding or postoperative blood product transfusion. Follow-up echocardiography in anticoagulated patients is recommended to rule out significant sanguineous pericardial effusions in the early postoperative period following hospital discharge.

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.

Reasons for Nonadherence to the Direct Oral Anticoagulant Apixaban: A Cross-Sectional Survey of Atrial Fibrillation Patients

Background

Nonadherence to direct oral anticoagulants to prevent stroke occurs in up to 40% of atrial fibrillation patients. Underlying reasons are poorly understood.

Objectives

This study quantified patient-reported reasons for nonadherence and identified strategies to improve adherence.

Methods

This is a cross-sectional survey of atrial fibrillation patients in 2 academic health systems who reported apixaban nonadherence. We examined patient-reported reasons for nonadherence and level of nonadherence (assessed by a validated 3-item adherence measure) using a multivariable logistic regression model.

Results

Of 419 study patients, 41.5% were women. The mean age was 71.1 ± 10 years and mean CHA2DS2VASc score was 3.2 ± 1.6. About two-thirds had adherence scores ≥80 (mild nonadherence) and one-third scores <80 (poor adherence). In all groups, forgetfulness contributed to nonadherence. Attitudes/beliefs associated with adherence score <80 included: not believing apixaban was needed (odds ratio [OR]: 12.24 [95% CI: 2.25-66.47]); medication cost (OR: 3.97 [95% CI: 1.67-9.42]); and fear of severe bleeding (OR: 3.28 [95% CI: 1.20-8.96]). Strategies that patients with adherence scores <80 selected as helping "a great deal/a lot" to increase adherence included bloodwork to evaluate efficacy (56%), physician counseling about adherence (55%), and having a reversal agent (39%). Almost one-half of all patients did not disclose nonadherence to their providers.

Conclusions

Patients may not disclose their nonadherence to prescribers, and attitudes related to apixaban nonadherence differ among patients with mild nonadherence versus poor adherence. While all patients may benefit from strategies to address forgetfulness, concerns related to the purpose of apixaban, cost, and bleeding risk may require special attention in those with poor adherence.

Assessment of adherence, treatment satisfaction and knowledge of direct oral anticoagulants in atrial fibrillation patients

AIM

The direct oral anticoagulants (DOACs) are increasingly used for stroke prevention in atrial fibrillation (AF). However, little is known about the association between medication adherence, patient satisfaction and treatment knowledge. The objective was to determine patients' DOAC adherence and their treatment satisfaction over time. Furthermore, we respectively investigated possible associations of treatment satisfaction and treatment knowledge in relation to adherence.

METHODS

Longitudinal study conducted in AF patients hospitalized in 2019 in a tertiary university hospital. DOAC adherence, treatment satisfaction and knowledge were assessed with validated questionnaires. Mixed effects logistic regression was modelled to investigate the effect of both treatment satisfaction and knowledge on DOAC adherence over time.

RESULTS

In total, 164 patients participated of which 128 and 101 patients could be recontacted after a period of respectively 3 (first contact) and 6 months (second contact) to assess adherence and treatment satisfaction. Suboptimal adherence was observed in 40.6% of the patients after 3 months and in 42.6% after 6 months (p=0.78). There was no significant difference (p=0.29) in the total score for treatment satisfaction between the first (79.2%) and the second contact (80.6%). DOAC adherence was not affected by time (p=0.71) nor by total knowledge score (p=0.61) or treatment satisfaction score (p=0.34). Nonetheless, a strong correlation between treatment satisfaction and knowledge was found (p=0.004).

CONCLUSION

DOAC adherence was suboptimal. Treatment satisfaction and knowledge were not associated with DOAC adherence over a 6 month period. Knowledge gaps were identified that could be remediated through patient education and follow-up.

Development of a New Patient-Reported Medication Adherence Instrument: Concerns Influencing Medication Adherence

PURPOSE

The purpose of this research was to conceptualize and develop a tool for identifying persons who are, or are likely to be, non-adherent to medications prescribed by their healthcare provider(s) by identifying concerns that patients have regarding their treatments.

PATIENTS AND METHODS

The target populations were persons diagnosed with atrial fibrillation or osteoarthritis, who were prescribed anticoagulants or over-the-counter or prescription pain medications, respectively. In this two-stage, multi-year, qualitative research study, relevant concepts were explored, confirmed and refined. The focus was on non-adherence due to active (thus potentially modifiable) patient decisions to forego taking medications as prescribed.

RESULTS

The most common concerns among participants with atrial fibrillation were medication-related side effects and fear of bleeding. Participants with osteoarthritis were most concerned about short-term stomach problems and long-term kidney and liver side effects. The Concerns Influencing Medication Adherence (CIMA) instrument was developed based on these concerns and those identified in the literature. It is comprised of 16 items: a core set of 11 items potentially applicable to multiple disease states, 3 items specific to atrial fibrillation, and 2 items unique to osteoarthritis. The instrument is intended to be completed electronically, and publicly available for use in direct patient care in the United States or in population health management.

CONCLUSION

To our knowledge, this is the first instrument focused on medication adherence that includes documented details of patient input as recommended by the United States Food and Drug Administration guidance. Patient input is considered a key component of content validity. In this research, for example, the concerns that patients have regarding their treatments can be expected to have affected past medication adherence and can potentially impact future adherence. Although applicability outside atrial fibrillation or osteoarthritis was not assessed, the general items may be useful in assessing adherence in other chronic diseases.

Differences in Perceived and Predicted Bleeding Risk in Older Adults With Atrial Fibrillation: The SAGE-AF Study

Background Little research has evaluated patient bleeding risk perceptions in comparison with calculated bleeding risk among oral anticoagulant users with atrial fibrillation. Our objective was to investigate underestimation of bleeding risk and to describe the characteristics and patient-reported outcomes associated with underestimation of bleeding risk. Methods and Results In the SAGE-AF (Systematic Assessment of Geriatric Elements in Atrial Fibrillation) study, a prospective cohort study of patients ≥65 years with atrial fibrillation, a CHA2DS2-VASc risk score ≥2 and who were on oral anticoagulant therapy, we compared patients' self-reported bleeding risk with their predicted bleeding risk from their HAS-BLED score. Among the 754 participants (mean age 74.8 years, 48.3% women), 68.0% underestimated their bleeding risk. Participants who were Asian or Pacific Islander, Black, Native American or Alaskan Native, Mixed Race or Hispanic (non-White) (adjusted OR [AOR], 0.45; 95% CI, 0.24-0.82) and women (AOR, 0.62; 95% CI, 0.40-0.95) had significantly lower odds of underestimating their bleeding risk than respective comparison groups. Participants with a history of bleeding (AOR, 3.07; 95% CI, 1.73-5.44) and prior hypertension (AOR, 4.33; 95% CI, 2.43-7.72), stroke (AOR, 5.18; 95% CI, 1.87-14.40), or renal disease (AOR, 5.05; 95% CI, 2.98-8.57) had significantly higher odds of underestimating their bleeding risk. Conclusions We found that more than two-thirds of patients with atrial fibrillation on oral anticoagulant therapy underestimated their bleeding risk and that participants with a history of bleeding and several comorbid conditions were more likely to underestimate their bleeding risk whereas non-Whites and women were less likely to underestimate their bleeding risk. Clinicians should ensure that patients prescribed oral anticoagulant therapy have a thorough understanding of bleeding risk.

Impact of an extended International Normalized Ratio follow-up interval on healthcare use among veteran patients on stable warfarin doses

PURPOSE

To analyze the impact of a 12-week extended International Normalized Ratio (INR) follow-up interval on healthcare use.

METHODS

A prospective cohort study of the use of an extended INR follow-up interval of up to 12 weeks was conducted over 2 years in a pharmacist-managed anticoagulation clinic. A detailed protocol was used to extend the INR follow-up interval to 5-6 weeks and then 7-8 weeks and 11-12 weeks. The number of planned and unplanned anticoagulation encounters, procedures requiring warfarin interruption, telephone triage phone calls, emergency department visits, and hospitalizations were collected. A post hoc subanalysis was also completed on participants who were scheduled for 4 consecutive 12-week intervals.

RESULTS

Compared to baseline, at 12 months there was a mean decrease in planned anticoagulation encounters of 2.24 visits (p < 0.001) among 44 participants. From 12 to 24 months compared to baseline, there was a mean decrease in planned anticoagulation encounters of 3.13 visits (p < 0.001) and an increase of 0.54 unplanned anticoagulation encounters (p = 0.04) among 39 participants. The remainder of healthcare use variables were not statistically significantly different from baseline at any time point. Of the 15 participants scheduled for 4 consecutive 12-week intervals, there was a decrease from baseline of approximately 5 visits over the course of a year (p < 0.001).

CONCLUSION

An extended INR follow-up interval appears to decrease anticoagulation healthcare use without an increase in acute healthcare use. While this intervention could be cost-effective, institutions need to consider safety, efficacy, and feasibility prior to implementation.

Veterans Perceptions of Satisfaction and Convenience with Anticoagulants for Atrial Fibrillation: Warfarin versus Direct Oral Anticoagulants

BACKGROUND

Atrial fibrillation (AFib) is associated with high morbidity and mortality. Traditionally, AFib was treated with warfarin, yet recent evidence suggests patients may favor direct oral anticoagulants (DOACs). Variation in preferences is common and we explored patients' perceptions of satisfaction and convenience of DOACs versus warfarin within the Veterans Health Administration (VA).

PATIENTS AND METHODS

We administered a cross-sectional survey, the Perception of Anticoagulant Treatment Questionnaire 2 (PACT-Q2), to Veterans residing in New England, age ≥65, diagnosed with AFib, and actively taking anticoagulant medication in fiscal year 2018. Survey recipients were randomly selected among patients on warfarin (n=200) or DOACs (n=200). A selection of survey respondents agreed to a follow-up semi-structured interview (n=16) to further investigate perceptions of satisfaction and convenience.

RESULTS

Of 400 patients, 187 completed the PACT-Q2 survey (49% on DOACs; 51% on warfarin). DOACs received significantly higher convenience ratings than warfarin (87.6, SD 13.5 vs 81.1, SD 18.8; p=0.007); there was no difference in satisfaction (64.2, SD 20.5 SD, warfarin vs, 67.3, SD 19.4, DOACs). Interview results showed that participants perceived their treatment to be convenient. However, participants expressed challenges related to the convenience of taking warfarin or DOACs, such as warfarin users having to follow dietary recommendations or DOAC users desiring some additional monitoring to answer questions or concerns. Overall, warfarin and DOAC users reported satisfaction with ongoing monitoring methods, although a few DOAC users expressed uncertainties with the frequency of monitoring. For most participants, concerns about side effects did not differ by anticoagulant type nor affect satisfaction.

CONCLUSION

Our survey and interview results showed variable patient satisfaction and perceptions of convenience with both DOACs and warfarin. Although DOACs are increasingly prescribed for AFib, some Veterans felt that regular follow-up on warfarin was advantageous. Our findings demonstrate the importance of patient-centered decision-making in AFib treatment in the VA patient population.

Assessing patient preferences for switching from warfarin to direct oral anticoagulants

Warfarin remains the most commonly prescribed oral anticoagulant in the United States, but it has disadvantages such as dietary interactions and frequent laboratory monitoring. Direct oral anticoagulants (DOACs) have been introduced as safer and equally effective alternatives to warfarin. This study assessed patient preference for warfarin or DOAC based on a willingness to pay more for potential DOAC benefits. Current warfarin patients with atrial fibrillation or venous thromboembolism enrolled in the University of Utah Health Thrombosis Service were given a one-time electronic survey that assessed preferences between warfarin and DOACs using scenarios comparing effectiveness, safety, and convenience. When DOACs were preferred, patients were asked how much more they would be willing to pay monthly for the perceived advantages associated with DOACs. With 123 completed surveys, 68% of patients preferred to stay on warfarin. No particular factor influenced patient preference (lack of routine laboratory monitoring, lower risks of major bleeding, and fewer dietary interactions). Reduced stroke risk was associated with the highest value (willing to pay an additional $21). Considering all factors, patients preferring DOACs would pay a median $18 extra per month for the additional benefits. Prior exposure to DOACs was associated with preference for DOACs. Many patients currently taking warfarin preferred to stay on warfarin when given the choice, despite DOAC benefits. Willingness to pay extra for DOAC advantages did not exceed $20 in the majority of survey respondents. Previous DOAC exposure influences patient preference and perceived value for DOACs.

Treatment Expectations, Convenience, and Satisfaction with Anticoagulant Treatment: Perceptions of Patients in South-East Queensland, Australia

Background: Warfarin has long been the only oral anticoagulant (OAC) available, but options now include non-vitamin K antagonists. Prescribing an OAC may be influenced by patient factors and preferences influenced by dosing, monitoring, and adverse effects, which may ultimately impact patient satisfaction and convenience. The aim of this study was to explore the perception of OAC treatment by Australian patients in terms of treatment expectations, convenience, and satisfaction. Methods: The Perception of Anticoagulant Treatment Questionnaire was distributed to patients dispensed OAC medication from three pharmacies in South-East Queensland. Responses to questions using a five-point Likert scale were collated and mean results utilised to assess expectations, convenience, and satisfaction, including an analysis across demographic groups. Results: A total of 56 (26.8%) surveys were returned, with the majority of respondent’s male (58.2%). Highest mean scores for treatment expectation were for an OAC that was easy to take (4.85 ± 0.79) and that could be taken care of by the respondents themselves (4.11 ± 1.14). The mean overall score for convenience was 68.90 ± 11.44% and for satisfaction 69.43 ± 16.58%. Significantly higher mean convenience scores were found in females and patients with atrial fibrillation. Conclusions: Patients’ highest expectations were for an OAC that would be easy to take, and overall satisfaction and convenience was around 69%. Factors including demographics can influence perceptions of therapy, and addressing individual preferences for OAC therapy may increase ratings of satisfaction and convenience.

Feasibility and safety of a 12-week INR follow-up protocol over 2 years in an anticoagulation clinic: a single-arm prospective cohort study

The 2012 American College of Chest Physicians' guidelines recommended a 12-week INR follow-up interval may be appropriate for patients on stable warfarin doses. Limited evidence supports this recommendation. A single-arm, prospective cohort study over 24 months was completed in a Veterans Affairs anticoagulation clinic to determine the long-term feasibility and safety of implementing an extended INR follow-up interval in Veterans on stable doses of warfarin. Participants were required to have a stable warfarin dose for 6 months prior to enrollment. A prespecified protocol was used to titrate, extend, and manage the INR interval up to 12 weeks. Scheduling of extended INR intervals was a primary outcome. Safety outcomes included major and serious bleeding and thromboembolic events. A post-hoc comparison of baseline characteristics between individuals who were scheduled for at least 4 consecutive 12-week INR follow-up intervals and those who were not was completed. Of the 50 participants, 36 (72%) were scheduled for at least one 12-week interval and 15 (30%) were scheduled for 4 consecutive intervals. There were 2 thromboembolic events that occurred in 1 participant. There were 28 major and serious bleeding events in 19 participants; 8 occurred while on the extended INR interval. In the post-hoc analysis, no participants scheduled for 4 consecutive 12-week intervals had heart failure. Based on 2 years of monitoring, a 12-week INR follow-up interval using a detailed protocol with titration of INR interval extension appears feasible for a subset of patients. Patients with heart failure may not be suitable for this intervention.

Racial, Ethnic, and Socioeconomic Inequities in the Prescription of Direct Oral Anticoagulants in Patients With Venous Thromboembolism in the United States

BACKGROUND

Beginning in 2012, direct oral anticoagulants (DOACs) were approved for treatment and prevention of venous thromboembolism. Prior investigations have demonstrated slow rates of adoption of novel therapeutics for black patients. We assessed the association of racial/ethnic and socioeconomic factors with DOAC use among commercially insured venous thromboembolism patients.

METHODS AND RESULTS

We performed a retrospective cohort analysis of adult patients with an incident diagnosis of venous thromboembolism between January 2010 and December 2016 using OptumInsight's Clinformatics Data Mart. We identified the first filled oral anticoagulant prescription within 30 days of discharge of an inpatient admission. We performed a multivariable logistic regression, adjusting for age, sex, race/ethnicity, region, zip code-linked household income, and clinical covariates to identify factors associated with the use of DOACs. Race and ethnicity were determined in this database through a combination of public records, self-report, and proprietary ethnicity code tables. There were 14 140 patients included in the analysis. Treatment with DOACs increased from <0.1% in 2010 to 65.6% in 2016. In multivariable analyses, black patients were less likely to receive a DOAC compared with white patients (odds ratio, 0.86; 95% CI, 0.77-0.97; P=0.02). There were no differences in DOAC utilization among Asian (odds ratio, 1.06; 95% CI, 0.75-1.49; P=0.74) or Hispanic patients (odds ratio, 1.04; 95% CI, 0.88-1.22; P=0.66) compared with whites. Patients with a household income over $100 000 per year were more likely to receive DOAC therapy compared with patients with a household income of <$40 000 per year (odds ratio, 1.50; 95% CI, 1.33-1.69; P<0.0001).

CONCLUSIONS

Although DOAC adoption has increased steadily since 2012, among a commercially insured population, black race and low household income were associated with lower use of DOACs for incident venous thromboembolism despite controlling for other clinical and socioeconomic factors. These findings suggest the possibility of both racial and socioeconomic inequity in access to this novel pharmacotherapy.

Drug-drug interactions in an era of multiple anticoagulants: a focus on clinically relevant drug interactions

Oral anticoagulants are commonly prescribed but high risk to cause adverse events. Skilled drug interaction management is essential to ensure safe and effective use of these therapies. Clinically relevant interactions with warfarin include drugs that modify cytochrome 2C9, 3A4, or both. Drugs that modify p-glycoprotein may interact with all direct oral anticoagulants, and modifiers of cytochrome 3A4 may interact with rivaroxaban and apixaban. Antiplatelet agents, nonsteroidal anti-inflammatory drugs, and serotonergic agents, such as selective serotonin reuptake inhibitors, can increase risk of bleeding when combined with any oral anticoagulant, and concomitant use should be routinely assessed. New data on anticoagulant drug interactions are available almost daily, and therefore, it is vital that clinicians regularly search interaction databases and the literature for updated management strategies. Skilled drug interaction management will improve outcomes and prevent adverse events in patients taking oral anticoagulants.

Drug-drug interactions in an era of multiple anticoagulants: a focus on clinically relevant drug interactions

Oral anticoagulants are commonly prescribed but high risk to cause adverse events. Skilled drug interaction management is essential to ensure safe and effective use of these therapies. Clinically relevant interactions with warfarin include drugs that modify cytochrome 2C9, 3A4, or both. Drugs that modify p-glycoprotein may interact with all direct oral anticoagulants, and modifiers of cytochrome 3A4 may interact with rivaroxaban and apixaban. Antiplatelet agents, nonsteroidal anti-inflammatory drugs, and serotonergic agents, such as selective serotonin reuptake inhibitors, can increase risk of bleeding when combined with any oral anticoagulant, and concomitant use should be routinely assessed. New data on anticoagulant drug interactions are available almost daily, and therefore, it is vital that clinicians regularly search interaction databases and the literature for updated management strategies. Skilled drug interaction management will improve outcomes and prevent adverse events in patients taking oral anticoagulants.

Physicians' views on patient participation in choice of oral anticoagulants in atrial fibrillation-a qualitative study

Direct oral anticoagulants provide an alternative to vitamin K antagonists for the anticoagulation therapy in atrial fibrillation (AF). The availability of several treatment options with different attributes makes shared decision-making appropriate for the choice of anticoagulation therapy. The aim of this study was to understand how physicians choose an oral anticoagulant (OAC) for patients with AF and how physicians view patients' participation in this decision. Semi-structured interviews with 17 Finnish physicians (eight general practitioners and nine specialists) working in the public sector were conducted. An interview guide on experience, prescribing and opinions about oral anticoagulants was developed based on previous literature. The data were thematically analysed using deductive and inductive approaches. Based on the interviews, patient's opinion was the most influential factor in decision-making when there were no clinical factors limiting the choice between OACs. Of patient's preferences, the most important was the attitude towards co-payments of OACs. Patients' opinions on monitoring of treatment, dosing and antidote availability were also mentioned by the interviewees. The choice of an OAC in AF was patient-centred as all interviewees expressed that patient's opinion affects the choice.