Warfarin Patient Safety is an audittool developed by PRIMIS and

funded by Boehringer Ingelheim. It is available to GP practices in Englandfor free. The tool enables practices toaudit their clinical data in order to lookat the appropriateness of warfarin pre-scribing.

In particular, the tool assists in exam-ining whether patients are benefittingfrom taking warfarin by calculating theamount of time their international nor-malised ratio (INR) is within therapeuticrange (TTR).

What does the audit do?The audit tool is concerned with patientswho are established on warfarin, and it isbased on patients who are currently reg-istered at the practice who have had anissue with warfarin both recently (in thelast three months) and historically (in thelast 12 months). This produces a cohortthat is more relevant for the analyses.

The audit tool:• calculates the percentage of TTR fromthe INRs recorded in the patient’s elec-tronic record• identifies patients with out-of-rangeINRs as recommended in the BritishCommittee for Standards in Haematology(BCSH) guidelines on oral anticoagula-tion1

•calculates the HAS-BLED bleeding riskscore2 (patients with atrial fibrillation only)and compares it with the patient’sCHADS2 score

3

• reports on patients with or without anidentified coded reason for being on war-farin and patients with or without a codedannual warfarin assessment.

How does the audit work?The audit tool operates in conjunctionwith the Care and Health Analysis in RealTime (CHART) software tool, also pro-duced by PRIMIS (see Prescriber 5November 2013;24[21]:15–18). CHARTis a Microsoft Excel-based programdesigned to support GP practices in car-rying out clinical audit and data qualityreviews.

GP practices use the various displayswithin CHART to review clinical data atboth patient and practice level, enablingthem to maintain an overall picture ofhow they are managing patients at apopulation level but at the same timelook in detail at the care of individualpatients.

The Warfarin Patient Safety audit toolproduces a practice report summarisingthe outcome, together with some sug-gested actions.

The results are displayed in a user-friendly format with easy-to-read graphs,

PRESCRIBING SUPPORT n

Prescriber July/August 2014 z 33prescriber.co.uk

Warfarin Patient Safety: freeanalysis tool for GP practicesJohn Robinson MRCGP, DA, DRCOG and Kerry Oliver

The authors describe howthe freely available WarfarinPatient Safety audit tool canhelp GP practices managetheir warfarin patients moresafely and effectively.

KEY POINTS

n the Warfarin Patient Safety tool is available for free to GPpractices in England

n it audits patients established on warfarin who have had aproblem both recently and historically

n it calculates the percentage of TTR, identifies patients without-of-range INRs and calculates HAS-BLED scores forcomparison with CHADS2

n it works in conjunction with CHART to review clinical dataat both patient and practice level

n categories reported on in the audit tool are based on spe-cific recommended safety indicators for patients estab-lished on anticoagulation

tables and an evidence-based narra-tive.

Audit examplesTTRIt is critical that patients prescribed war-farin achieve their desired INR for anti -coagulation to be effective. The audit tooluses the Rosendaal4 method to calculatethe TTR percentage.

Evidence from a study on patients withatrial fibrillation5 indicates that only patientswith a TTR greater than 70 per cent have asignificantly reduced risk of stroke, and onlythose with control in excess of over 40 percent have significantly improved outcomesin terms of overall mortality compared totreatment without warfarin. The data aregrouped as such within the audit tool (seeFigure 1 and 2).

Out-of-ranges INR resultsA patient’s risk of bleeding increases withtheir INR. The categories reported on inthe audit tool are based on specific rec-ommended safety indicators for patientsestablished on anticoagulation. Thesepatients need to be reviewed to see ifthere is anything that can be done toimprove their control (see Figure 3): • INR >5 – the risk of bleeding is signifi-cantly increased • INR >8 – can be dangerous andrequires urgent reversal • INR >1 unit below target – patients aregenerally not adequately anticoagulated.

HAS-BLED scoreHAS-BLED is a bleeding risk assess-ment tool used for patients with atrialfibrillation. The new guidance fromNICE6 on the management of atrial fib-rillation recommends that GPs shoulduse the HAS-BLED score to assess therisk of bleeding both when initiatinganticoagulation therapy and monitoringpatients.

A HAS-BLED score of 3 or more is gen-erally considered high risk but this aloneshould not stop the use of anticoagula-tion therapy (see Figure 4).

HAS-BLED can be used with theCHADS2 or CHADS2-VASc scores to helpclinicians balance the risk of bleedingwith the risk of stroke, determiningwhether anticoagulation is in the bestinterest of the patient.

Future plansCHART works in conjunction with CHARTOnline, a secure web-enabled tool allow-ing nonidentifiable practice data to beshared for comparative analysis. PRIMISplans to develop a CHART Online versionof the Warfarin Patient Safety audit tool

so that practices can compare their carewith that of other practices nationally,locally or at CCG level.

PRIMIS PRIMIS is a business unit in the Divisionof Primary Care at The University ofNottingham (www.nottingham.ac.uk/primis). PRIMIS provides education andinformatics services to GP practices, theNHS, commercial organisations andresearchers.

Both CHART and the Warfarin PatientSafety audit tool are free to use by all GPpractices in England and can be down-loaded by members of the PRIMIS Hub.Hub members have access to informa-tion, advice, training and tools aimed atsupporting effective use of health infor-mation, helping to achieve better healthoutcomes.

PRIMIS’s development of the audittool has been funded by BoehringerIngelheim Ltd. PRIMIS retains editorialcontrol and intellectual property rights forthe audit tool.

References1. Baglin TP, et al. Br J Haematol 2006;136:26–9.2. Pisters R, et al. Chest 2010;138:1093–100.3. The Task Force for the Management of Atrial Fibrillation of the European Society ofCardiology. Eur Heart J 2010;31(19):2369–429.4. Rosendaal FR, et al. Thromb Haemost1993;69(3):236–9.5. Morgan CL, et al. Thromb Res 2009;124:37–41.6. NICE. The management of atrial fibrillation.CG180. June 2014.

Dr Robinson is a GP and clinical adviserand Kerry Oliver is managing director atPRIMIS, University of Nottingham

n PRESCRIBING SUPPORT l Warfarin Patient Safety

34 z Prescriber July/August 2014 prescriber.co.uk

Figure 1. A practice report showing that nine patientshave a TTR of less than 40 per cent; a further 47 patientshave a TTR of 40–70 per cent

Figure 2. The datasheet enables practices toeasily access and sort the TTRs for each pa-tient included in the audit; L6M = last sixmonths, L3M = last three months

Figure 3. The practice report shows both the number ofINRs and the number of patients involved (the number ofpatients appears in brackets), categorised according tosafety indicators

Figure 4. The audit tool shows that there are 17 patients on warfarin with a HAS-BLED scoreof 3 or more (dark blue) and 14 patients on warfarin with a low-risk CHADS2 score (first row)