Home About us Editorial board Search Ahead of print Current issue Archives Submit article Instructions Subscribe Contacts Login 
  Users Online: 67 Home Print this page Email this page Small font sizeDefault font sizeIncrease font size  

 Table of Contents  
ORIGINAL ARTICLE
Year : 2021  |  Volume : 11  |  Issue : 3  |  Page : 177-181  

Cross-sectional survey of anticoagulant use among specialist physicians with a focus on direct anticoagulants


1 Department of Medical Oncology, Dayanand Medical College, Ludhiana, Punjab, India
2 Department of Nephrology, Dayanand Medical College, Ludhiana, Punjab, India
3 Department of Periodontics, Christian Dental College, Ludhiana, Punjab, India
4 New Medical College and Hospital, Kota, Rajasthan, India
5 Department of Internal Medicine, New Medical College, Kota, Rajasthan, India
6 Department of Clinical Hematology and Oncology, Dayanand Medical College, Kota, Rajasthan, India
7 Department of Neurology, Dayanand Medical College, Kota, Rajasthan, India

Date of Submission17-Feb-2021
Date of Acceptance27-May-2021
Date of Web Publication19-Jul-2021

Correspondence Address:
Suvir Singh
Department of Clinical Hematology and Stem Cell Transplantation, Dayanand Medical College and Hospital, Ludhiana - 141 001, Punjab
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/ijabmr.ijabmr_135_21

Rights and Permissions
   Abstract 


Introduction: Direct oral anticoagulants (DOACs) have been available for clinical use since 2010 and offer the advantages of a lower bleeding risk with similar efficacy compared to Vitamin K antagonists (VKAs). However, no data is available on practice patterns anticoagulation usage and determinants of the same among physicians in India. Methods: A cross-sectional survey was conducted using Google Forms comprising of 24 questions in 4 categories on baseline information, practice details, knowledge, and outlook. Results: A total of 412 physicians were contacted, of which complete responses were received from 50 (12%). Majority had a subspecialist (58%) or a specialist (32%) qualification, with 54% working in a medical college. VKAs were the preferred first-line agent for 46%, with the most common perceived disadvantage being need of regular monitoring. The absence of regular blood testing was the most prominent advantage attributed to novel oral anticoagulants (NOACs) by 76% participants. Equivalent number of participants perceived efficacy to be similar in both groups, and 86% indicated NOACs to have better safety. Most participants responded to knowledge-based questions correctly and cited high costs of DOACs as the most common barrier to clinical use (78%). Conclusions: Our survey indicates VKAs as the preferred first-line agents despite perceived disadvantages. Among specialist physicians, high drug costs and not lack of knowledge or familiarity appear to be predominant factors precluding more frequent use of NOACs.

Keywords: Acitrom, bleeding, novel oral anticoagulant, thrombosis, warfarin


How to cite this article:
Singh J, Sethi S, Kaur T, Bhardwaj A, Meena M, Singh S, Singla M. Cross-sectional survey of anticoagulant use among specialist physicians with a focus on direct anticoagulants. Int J App Basic Med Res 2021;11:177-81

How to cite this URL:
Singh J, Sethi S, Kaur T, Bhardwaj A, Meena M, Singh S, Singla M. Cross-sectional survey of anticoagulant use among specialist physicians with a focus on direct anticoagulants. Int J App Basic Med Res [serial online] 2021 [cited 2021 Oct 17];11:177-81. Available from: https://www.ijabmr.org/text.asp?2021/11/3/177/321799




   Introduction Top


Oral anticoagulants are the mainstay of treatment for the prevention of recurrent venous thromboembolism (VTE) and ischemic stroke in atrial fibrillation.[1] VTE includes deep venous thrombosis (DVT) and pulmonary embolism (PE) and constitutes a significant global health-care burden, with an estimated incidence of 115–269 and mortality of 9–32 per 100,000 population.[2] A similar burden is imposed by atrial fibrillation, with an estimated 33 million patients worldwide as of 2010, which is expected to be much higher at present.[3] Before directly acting oral anticoagulants (DOACs) were introduced in 2010, Vitamin K antagonists (VKAs) were only oral agents available for continued anticoagulation.[4]

Since 2010, several DOACs utilizing newly defined and distinct mechanisms in the coagulation system have been introduced, with a better safety profile and lower bleeding risk, while providing at least equivalent efficacy to VKAs.[5],[6] However, there have been several barriers to adoption of DOACs as first-line agents for oral anticoagulation, including high costs and incomplete information about clinical usage and management of complications.[7],[8] Seemingly, VKAs appear to be the most common anticoagulants prescribed in clinical use, and the factors leading to physician preference in choice of initial agent are not well defined. We performed this pilot study to evaluate physician preferences in anticoagulant use and possible determinants of the same.


   Methods Top


This study was conducted as a cross-sectional survey. The questionnaire was developed as a qualitative questionnaire to be administered through Google Forms. Initial questionnaire development was performed by a writing committee comprising of physicians from nephrology, dental sciences, and internal medicine. Questionnaire sequence and language were finalized discursively. Subsequently, a questionnaire review was performed by an expert board comprising three physicians from medical specialties, following which it was pretested on a group of five physicians. The questionnaire was revised and finalized based on feedback received during validation and pretesting. A total of 24 questions were finalized with the four categories as – baseline information (4 questions); clinical practice (7 questions); knowledge (9 questions); and outlook/attitude (4 questions).

The questionnaire was applied as a pilot survey among a group of five physicians to assess spelling errors and ambiguous questions, which were modified before the survey was finalized. The questionnaire was sent by E-mail and WhatsApp to intended participants, constituting physicians from various specialties and levels of experience. To ensure maximum responses, the questionnaire was distributed thrice among the intended participants. Data were compiled in Google Forms and analyzed using Microsoft Excel.


   Results Top


Baseline data

A total of 412 physicians were contacted among various specialties (140 through E-mail and 272 through WhatsApp), of which complete responses were obtained by 50, providing an overall response rate of 12%. A majority of respondents had a subspecialty qualification including DM/MCh (n = 29, 58%), followed by MD/MS in 16 (32%). The site and type of practice included private medical college in 17 (34%) respondents, followed by private hospital in 16 (32%) and government medical college in 10 (20%). Most participants (n = 44, 88%) reported seeing more than 30 patients in outpatient clinics per week, with the majority (n = 33, 66%) having 2–5 patients per week on anticoagulation. Twenty-three (46%) respondents had <5 patients following up on DOACs per week while 26 (52%) had more than five. Baseline data of respondents are summarized in [Table 1].
Table 1: Baseline information on practice characteristics of respondents

Click here to view


Clinical practice and perceptions

The choice of initial agent for anticoagulation was VKA in a majority of respondents (n = 23, 46%), followed by Dabigatran (n = 11, 22%). Overall, 42 (84%) participants reported ever having started DOAC for any new patient. Among those who had started a DOAC, the agent of choice was dabigatran in 24 (57%), followed by rivaroxaban in 11 (26%) and apixaban in 7 (16%). Indications for starting a DOAC included DVT/PE in 21 (50%) and atrial fibrillation in 16 (38%). While using VKAs, 44 (88%) reported requesting for a prothrombin time/international normalized ratio (INR) with each visit, but only 12 (24%) reported complete patient compliance in getting tested for INR. [Table 2] summarizes salient features of queries on clinical practice.
Table 2: Characteristics of clinical practice of anticoagulants

Click here to view


On being questioned about the reason for not choosing DOACs as first-line agents, a majority (n = 39, 78%) indicated cost as the major barrier. Inadequate information about clinical use and management of complications was less frequent, cited by 8 (16%) respondents. Most participants (n = 42, 84%) said that they would continue the same DOAC without modification if a patient was referred to them for follow-up. On being asked about problems with VKAs, the most common response cited was need of regular INR monitoring (n = 41, 82%), followed by food-drug interactions (n = 7, 14%). Only 3 (6%) respondents considered bleeding to be the most important problem with VKAs. Conversely, lack of regular blood testing was perceived to be the most attractive property of DOACs, reported by 38 (76%), followed by reduced bleeding risk by 6 (12%) and better efficacy by 5 (10%). Thirty participants (60%) indicated that even a fivefold difference in cost, if acceptable to patients, would make them prescribe DOACs as need of regular testing was obviated. Although we did not inquire about the preferred DOAC agent, most respondents (n = 38, 76%) indicated that twice a day administration would reduce patient compliance.

Knowledge-based questions

Most participants indicated journals as the predominant source of information on DOACs (n = 30, 60%), followed by conferences/meetings (n = 7, 14%). Pharmaceutical representatives, textbooks, and local meetings were uncommon sources and collectively constituted 12% of responses (n = 6). On being inquired about drugs with better efficacy, 21 (42%) selected warfarin while 26 (52%) selected DOACs. On asking about agents with a better safety profile, 43 (86%) respondents indicated DOACs to have a lesser bleeding risk than VKAs. Forty eight (96%) correctly indicated no need for regular blood testing while on DOACs. On being asked about conditions that precluded the use of DOACs, 39 (78%) correctly identified chronic kidney disease, with 5 (10%) indicating anemia and 3 (6%) ischemic heart disease as possible contraindications. Participants were also asked to respond to practice-based scenarios while using DOACs. On being asked about the best option to manage a patient in shock caused by Dabigatran-related bleeding, 15 (30%) chose fresh frozen plasma transfusion directly while 6 (12%) chose to check an activated partial thromboplastin time first. Seventeen (34%) selected looking for a specific antidote. On being asked about preoperative discontinuation of rivaroxaban, 34 (68%) correctly indicated stopping the drug 48 h preoperatively. [Figure 1]a illustrates responses to important perceived advantages of DOACs and [Figure 1]b and c to clinical scenario-based questions.
Figure 1: (a) Responses to most common perceived advantages of direct oral anticoagulants over Vitamin K antagonists, (b) Responses to the management of a critically ill patient in shock secondary to direct oral anticoagulant related bleeding, (c) Responses to preoperative management of rivaroxaban in a patient planned for elective surgery

Click here to view



   Discussion Top


Our study reports the results of a cross-sectional survey documenting physician preferences and determinants of the same while prescribing oral anticoagulant agents. Principal findings include a predilection toward VKAs as choice of first-line therapy, with cost being the most important barrier to DOAC usage.

Physician preference for VKAs as has been documented in several studies but is rapidly evolving as more patients receive DOACs as first-line agents.[9],[10] As anticoagulation must continue for a prolonged duration, cost, safety, and tolerability become major determinants of adherence and long-term outcomes. Despite robust data on safety and efficacy of VKAs available over the past six decades, several problems such as food-drug interactions and need for regular monitoring continue to persist. The introduction of ximelagatran in 2003 was the first step aimed to overcome these issues while maintaining equivalent efficacy compared to VKAs.[11]

A majority of respondents in our cohort identified VKAs to have better efficacy compared to DOACs, which is a predominant finding in most clinical trials comparing the two. For patients with atrial fibrillation, dabigatran,[12] rivaroxaban,[13] and apixaban[14] are found to be noninferior to VKAs for the prevention of ischemic stroke. All three agents have also been found to be noninferior to VKAs for patients for the prevention of recurrent VTE in patients receiving long-term anticoagulation.[15],[16],[17] A majority of our respondents correctly identified DOACs to have a lower risk of bleeding compared to VKAs. A lower bleeding risk is a predominant advantage of DOACs over VKAs noted in most clinical trials. In a meta-analysis including 12 studies with 77,000 patients with AF, DOACs were noted to have a 50% lower risk of major bleeding compared to VKAs.[18] A similar study including patients with VTE from six phase III trials also found a lower risk of bleeding with DOACs, while maintaining equivalent efficacy.[19]

Most participants indicated the need for regular INR monitoring to be the major disadvantage with VKAs and can affect the time in therapeutic range with VKAs, bringing down efficacy. Strict adherence to follow-up and INR monitoring was reported to be done by less than 1/3rd patients, a finding echoed in other published data.[20] Inadequate information about clinical usage and management of adverse events with DOACs is an apparent barrier to more frequent usage. This has been reported to be equally prevalent among junior and experienced physicians.[21] Surprisingly, we did not note a significant deficit in answers to knowledge-based questions on DOACs, with most participants answering questions on preoperative use of, management of bleeding and need of testing correctly.

Cost is one of the most important factors deciding initial anticoagulant usage.[22] As of January 2021, the approximate monthly cost of warfarin at a dose of 5 mg per day is ₹ 77 (US$ 1), compared to ₹ 1500 (US$ 20) for dabigatran at 150 mg twice a day, ₹ 3900 (US$ 53) for apixaban at 5 mg twice a day, and ₹ 3810 (US$ 52) for rivaroxaban at 20 mg once a day. However, direct costs paint an incomplete picture and may be modified with the emergence of generic manufacturers. Moreover, individual agents have a variable impact on recurrent VTE, therapy-related bleeding, and quality-adjusted life years and must take cost-effectiveness into account. A meta-analysis in 2018 evaluated 11 studies comparing DOACs with VKAs and found DOACs to be uniformly more cost-effective. The incremental cost-effectiveness ratio of any DOAC agent to VKA ranged from -60000US$ to -45000 US$.[23] Among the DOACs, apixaban appears to be the most cost-effective option, with a cost avoidance of approximately US$ 4000 per patient year.[24] Indigenous cost-effective analyses including local data are essential in reaching correct inferences.

Limitations

Our study may be limited by an over-representation of specialist physicians and may not provide a true picture of barriers to DOAC usage. Although response rates of 10%–20% are typical for a complex survey, a response rate of 12% noted by us may not provide a representative picture.[25]


   Conclusions Top


Our survey illustrates physician preferences in choosing initial oral anticoagulants and indicates lack of INR monitoring and better safety as the predominant advantages perceived with DOACs. Within our cohort of specialist physicians, knowledge about DOACs does not appear to be a major limiting factor and cost emerges as the predominant barrier for more frequent use.

Ethical clearance

IEC No: 2021-62 (DMCH, Ludhiana).

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
   References Top

1.
Harter K, Levine M, Henderson SO. Anticoagulation drug therapy: A review. West J Emerg Med 2015;16:11-7.  Back to cited text no. 1
    
2.
Wendelboe AM, Raskob GE. Global burden of thrombosis: Epidemiologic aspects. Circ Res 2016;118:1340-7.  Back to cited text no. 2
    
3.
Chugh SS, Havmoeller R, Narayanan K, Singh D, Rienstra M, Benjamin EJ, et al. Worldwide epidemiology of atrial fibrillation: A global burden of disease 2010 Study. Circulation 2014;129:837-47.  Back to cited text no. 3
    
4.
Bauersachs R, Breddin HK. Modern anticoagulation. Problems of the proven, hope for the new. Internist (Berl) 2004;45:717-26.  Back to cited text no. 4
    
5.
Makam RC, Hoaglin DC, McManus DD, Wang V, Gore JM, Spencer FA, et al. Efficacy and safety of direct oral anticoagulants approved for cardiovascular indications: Systematic review and meta-analysis. PLoS One 2018;13:e0197583.  Back to cited text no. 5
    
6.
Van Ganse E, Danchin N, Mahé I, Hanon O, Jacoud F, Nolin M, et al. Comparative safety and effectiveness of oral anticoagulants in nonvalvular atrial fibrillation. Stroke 2020;51:2066-75.  Back to cited text no. 6
    
7.
Wong SL, Marshall LZ, Lawson KA. Direct oral anticoagulant prescription trends, switching patterns, and adherence in Texas Medicaid. Am J Manag Care 2018;24:P309-14.  Back to cited text no. 7
    
8.
Dalal JJ, Dhall A, Bhave A. Current perspective on use of DOAC in clinical practice in India. J Assoc Physicians of India 2016;64:56.  Back to cited text no. 8
    
9.
Fosbøl EL, Vinding NE, Lamberts M, Staerk L, Gundlund A, Gadsbøll K, et al. Shifting to a non-vitamin K antagonist oral anticoagulation agent from vitamin K antagonist in atrial fibrillation. Europace 2018;20:e78-86.  Back to cited text no. 9
    
10.
Friberg L, Rosenqvist M, Lip GY. Net clinical benefit of warfarin in patients with atrial fibrillation: A report from the Swedish atrial fibrillation cohort study. Circulation 2012;125:2298-307.  Back to cited text no. 10
    
11.
Hrebickova L, Nawarskas JJ, Anderson JR. Ximelagatran: A new oral anticoagulant. Heart Dis 2003;5:397-408.  Back to cited text no. 11
    
12.
Connolly SJ, Ezekowitz MD, Yusuf S, Eikelboom J, Oldgren J, Parekh A, et al. Dabigatran versus warfarin in patients with atrial fibrillation. N Engl J Med 2009;361:1139-51.  Back to cited text no. 12
    
13.
Rocket AF Study Investigators. Rivaroxaban-once daily, oral, direct factor Xa inhibition compared with vitamin K antagonism for prevention of stroke and Embolism Trial in Atrial Fibrillation: Rationale and design of the ROCKET AF study. Am Heart J 2010;159:340-7.e1.  Back to cited text no. 13
    
14.
Lopes RD, Alexander JH, Al-Khatib SM, Ansell J, Diaz R, Easton JD, et al. Apixaban for reduction in stroke and other ThromboemboLic events in atrial fibrillation (ARISTOTLE) trial: Design and rationale. Am Heart J 2010;159:331-9.  Back to cited text no. 14
    
15.
Schulman S, Kearon C, Kakkar AK, Mismetti P, Schellong S, Eriksson H, et al. Dabigatran versus warfarin in the treatment of acute venous thromboembolism. N Engl J Med 2009;361:2342-52.  Back to cited text no. 15
    
16.
EINSTEIN Investigators, Bauersachs R, Berkowitz SD, Brenner B, Buller HR, Decousus H, et al. Oral rivaroxaban for symptomatic venous thromboembolism. N Engl J Med 2010;363:2499-510.  Back to cited text no. 16
    
17.
Agnelli G, Buller HR, Cohen A, Curto M, Gallus AS, Johnson M, et al. Apixaban for extended treatment of venous thromboembolism. N Engl J Med 2013;368:699-708.  Back to cited text no. 17
    
18.
Hicks T, Stewart F, Eisinga A. DOACs versus warfarin for stroke prevention in patients with AF: A systematic review and meta-analysis. Open Heart 2016;3:e000279.  Back to cited text no. 18
    
19.
Cohen AT, Hamilton M, Mitchell SA, Phatak H, Liu X, Bird A, et al. Comparison of the novel oral anticoagulants apixaban, dabigatran, edoxaban, and rivaroxaban in the initial and long-term treatment and prevention of venous thromboembolism: Systematic review and network meta-analysis. PLoS One 2015;10:e0144856.  Back to cited text no. 19
    
20.
Mayet AY. Patient adherence to warfarin therapy and its impact on anticoagulation control. Saudi Pharm J 2016;24:29-34.  Back to cited text no. 20
    
21.
Ahmed M, Gautam M. New oral anticoagulants (DOACs) vs. warfarin: Are doctors ready to switch? Eur Respir J 2015;46:PA2779.  Back to cited text no. 21
    
22.
Somani A, Raja V. Prevailing practices of usage of oral anticoagulant in stroke prevention in atrial fibrillation (SPAF) in Indian Patients: Results of a Multicenter, cross sectional questionnaire based physician survey. J Adv Med Med Res 2017:1-8.  Back to cited text no. 22
    
23.
Huang Y, Chen SH, Wang Y, Zhao B. cost effectiveness of direct oral anticoagulants (DOACS) compared with warfarin: A literature review. Value Health 2018;21:S60.  Back to cited text no. 23
    
24.
Al Mukdad M, Al-Badriyeh D, Elewa HF. Cost-effectiveness evaluations among the direct oral anticoagulants for the prevention and treatment of venous thromboembolism: Systematic review. Clin Appl Thromb Hemost 2019;25:1076029619849103.  Back to cited text no. 24
    
25.
Sahlqvist S, Song Y, Bull F, Adams E, Preston J, Ogilvie D, et al. Effect of questionnaire length, personalisation and reminder type on response rate to a complex postal survey: Randomised controlled trial. BMC Med Res Methodol 2011;11:62.  Back to cited text no. 25
    


    Figures

  [Figure 1]
 
 
    Tables

  [Table 1], [Table 2]



 

Top
 
 
  Search
 
    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Access Statistics
    Email Alert *
    Add to My List *
* Registration required (free)  

 
  In this article
    Abstract
   Introduction
   Methods
   Results
   Discussion
   Conclusions
    References
    Article Figures
    Article Tables

 Article Access Statistics
    Viewed460    
    Printed8    
    Emailed0    
    PDF Downloaded75    
    Comments [Add]    

Recommend this journal