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January • 17 • 2023

Avoiding Anticoagulant Errors: A National Priority for Reducing Adverse Drug Events


By Robin Webster, MHA, BSN, RN, CPHRM



Learn what to consider when prescribing, managing, and monitoring anticoagulants in order to increase the success of mitigating anticoagulant adverse drug events.

The National Action Plan for Adverse Drug Event Prevention identifies anticoagulants as the most common cause of error across all healthcare settings. The Joint Commission has made reducing the likelihood of patient harm associated with using anticoagulant therapy a National Patient Safety Goal for both the hospital and ambulatory care setting. Further, the Institute for Safe Medication Practices (ISMP) considers anticoagulants and direct oral anticoagulants (DOACs) to be high-alert medications that must be carefully managed and monitored in both the acute care and ambulatory care setting.

Not surprisingly, errors related to anticoagulation management have historically been the second-leading cause of Coverys’ medication-related claims. Forty-four percent of Coverys’ anticoagulation claims stem from initial medication ordering, while another 44% involve patient monitoring and management over time.
Warfarin is frequently involved in these claims. Failure to adequately monitor a patient on warfarin can lead to hemorrhage, stroke, and/or death. Monitoring problems include:
  • Failure to obtain baseline lab tests and/or to verify the most recent lab values before prescribing and administering an anticoagulant.
  • Adjusting warfarin doses too often without assessing overall trends in international normalized ratio (INR) values.
  • Failure to monitor INRs closely when medications known to interact with warfarin are prescribed.
  • Patient failure to comply with outpatient testing.
Mitigating anticoagulant adverse drug events is a national priority. Consider the following when prescribing, managing, and monitoring anticoagulants:
  • Develop protocols. Establish anticoagulation protocols that are based on evidence-based clinical guidelines and consensus statements. At a minimum, protocols should address the indication(s) for anticoagulation, patient selection criteria, expected therapy duration, types of anticoagulants included, and initiating and regulating anticoagulant medications. Specify in the protocol the time frames 
  • and testing that must be completed prior to initiating anticoagulation or DOAC therapy. Update protocols regularly or when guidelines change.
  • Develop written policies and procedures. Establish policies and procedures that address prescribing, dispensing, administering, monitoring, providing patient education, and follow-up on patients on anticoagulation therapy. Include clear guidelines for appropriate laboratory monitoring and a process for managing patients who fail to show for anticoagulation monitoring visits, whether the visits involve coagulation testing or follow-up.
  • Include clear monitoring guidelines. Be sure anticoagulation management policies and protocols include clear guidelines for appropriate laboratory monitoring. Specify in the protocol the time frames and testing that must be completed prior to initiating anticoagulation or DOAC therapy.
  • Addressing missing labs. Anticoagulation management policies and protocols should include prioritization guidelines for call backs and follow-up. For example, a missing INR for a patient whose most recent INR was significantly out of range requires immediate follow-up. Include a process for collaborating with patients who have NOT presented for INR testing as planned. Considerations might include identifying root causes or barriers to compliance, case management referral, and/or treatment plan changes.
  • Define critical lab values. Anticoagulation protocols should define critical values for the following:
    • Hemoglobin and hematocrit and platelet count (warfarin and DOACs).
    • Activated partial thromboplastin time (aPTT) and INR (warfarin).
    • Serum creatinine and estimated creatinine clearance (DOACs).
    • Ensure the organization’s critical values policy correlates with the policies of the laboratories, diagnostic facilities, and/or hospitals used to perform the testing.
  • Develop warfarin periprocedural transitioning guidelines. Injuries related to failure to resume warfarin after a procedure are a significant cause of anticoagulation-related claims. Many of these claims involve a miscommunication between the practitioner managing a patient’s anticoagulant treatment and the practitioner performing the procedure, resulting in a failure to adequately communicate to the patient when to resume warfarin. Establish specific guidelines for withholding warfarin before a procedure and resuming warfarin after the procedure that specify: 
    • The practitioner responsible for deciding to stop warfarin.
    • The practitioner responsible for notifying the patient when to stop warfarin.
    • The practitioner responsible for deciding to resume warfarin.
    • The practitioner responsible for notifying the patient to resume warfarin.
    • If a parenteral anticoagulant will be used during the bridge, the practitioner responsible for ordering the parenteral anticoagulant and how and where the patient will receive anticoagulant injections.
  • Centralize anticoagulation information. Providing a method for clinicians to view historical laboratory values from the computer order entry system makes it easier for the clinician to quickly determine trends over time when placing an order for an anticoagulant. Ensure staff members with patient care responsibilities can access all patient-specific anticoagulation therapy-related information, including anticoagulant name, patient risk factors, target INR range, treatment duration, laboratory/point-of-care testing (POCT) results, starting dose, and dose adjustments in one designated place in a patient’s health record. Make sure over-the-counter medications like aspirin are also included.
  • Maintain staff competency. A list of anticoagulation competencies is in the National Certification Board for Anticoagulation Care Providers’ Candidate Handbook for Certified Anticoagulation Care Provider. Implement role-specific annual competencies for practitioners who prescribe and dispense oral anticoagulants and the staff members who work with these clinicians. Include the following:
    • Anticoagulation-specific CEU requirements (as applicable).
    • New guideline recommendations.
    • Anticoagulant medication review for prescribers and nurses that includes indications, dose, risks, side effects, and contraindication.
    • Demonstration of POCT competency for all staff who use point-of-care devices.
    • A “sample patient” scenario or a case review as part of the evaluation process.
    • Annual competency documentation in the employee review process.
  • Educate patients. Because warfarin is a narrow therapeutic range medication, it can be complex for patients to manage, especially when there are alternating dosage strengths and dose alterations based on INR lab results. Provide oral and written anticoagulation plain language education materials to patients. Use teach-back techniques to ensure patient/family understanding. Include special instructions for warfarin patients that address:
    • Monitoring (INR testing, goal target range for patient, frequency of testing, etc.).
    • Keeping INR in range (consistent vitamin K content in diet, limit alcohol use, adhere to dosing instructions, etc.).
    • Factors influencing INR (dietary vitamin K intake, general health, activity level, alcohol, medications/supplements, etc.).
  • Obtain informed consent.  After educating patients and prior to prescribing an anticoagulant, inform patients of the risks, benefits, and alternatives to treatment with the medication plan and obtain their consent. Encourage the patient to ask questions about the anticoagulant and/or treatment plan. Document the consent discussion in the medical record. Have the patient sign an informed consent form as an adjunct to the documented discussion.
  • Monitor outcomes. Measure outcomes regularly and review all outcome measures being monitored at least annually to determine if goals are being met and if revisions are needed. Define what measurements to monitor. Consider including:
    • Patients maintained within target INR range.
    • INR levels associated with hemorrhagic complication and thromboembolism.
    • All deaths related to anticoagulant therapy.
    • Minor and major bleeding episodes.
    • Emergency department visits or hospitalizations due to anticoagulation problems.
    • Compliance with the protocols. 
Ordering, managing, and monitoring anticoagulants can be challenging and error prone. Proactively implementing risk management strategies is essential to reducing adverse drug events. 

Additional Resources: 
Copyrighted. No legal or medical advice intended. This post includes general risk management guidelines. Such materials are for informational purposes only and may not reflect the most current legal or medical developments. These informational materials are not intended, and must not be taken, as legal or medical advice on any particular set of facts or circumstances. 


  • Risk Management & Patient Safety