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Service improvement system to enhance the safety of patients admitted on long-term warfarin

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Service improvement system to enhance the safety of patients admitted on long-term warfarin

Abstract

It is common for hospital inpatients on warfarin to suffer from fluctuations in their INR (international normalised ratio). Raised INRs are potentially very dangerous and may result in acute life-threatening haemorrhages. Conversely, low INRs may increase the risk for the development of venous thromboembolism. Having observed many deranged INRs among hospital inpatients, we decided to focus our project on identifying the contributing factors to deranged INRs and ways to address this problem. We analysed the warfarin prescriptions on all drug charts and surveyed the junior doctor staff. Our results revealed poor knowledge and confidence levels on warfarin prescribing among junior doctor staff. This is likely to be reflected in the poor completion rate of warfarin prescriptions. We instituted practical changes to resolve the issue: most importantly, a change to the warfarin administration time from 6 pm to 2 pm, supported by a poster campaign to increase awareness of the problem. The objective of these changes was to reduce prescribing errors by reducing warfarin prescriptions out-of-hours, by the on-call doctors. We repeated the audit cycle twice. Although our interventions were successfully introduced as shown in our second audit cycle, the changes that were implemented were not sustained as shown in the third audit cycle. We identified a need for annual intervention to educate new junior doctor staff to ensure that the positive outcomes achieved are maintained in the long term.
BMJ Quality Improvement Reports 2014; u202818.w1361 doi: 10.1136/bmjquality.u202818.w1361
Service improvement system to enhance the safety of patients admitted on
long-term warfarin
Dana Warcel, Daniel Johnson, Neeraj Shah, Norman shreeve
North Middlesex University Hospital NHS Trust, London, United Kingdom.
Abstract
It is common for hospital inpatients on warfarin to suffer from fluctuations in their INR (international normalised ratio). Raised INRs are
potentially very dangerous and may result in acute life-threatening haemorrhages. Conversely, low INRs may increase the risk for the
development of venous thromboembolism. Having observed many deranged INRs among hospital inpatients, we decided to focus our project
on identifying the contributing factors to deranged INRs and ways to address this problem. We analysed the warfarin prescriptions on all drug
charts and surveyed the junior doctor staff. Our results revealed poor knowledge and confidence levels on warfarin prescribing among junior
doctor staff. This is likely to be reflected in the poor completion rate of warfarin prescriptions. We instituted practical changes to resolve the
issue: most importantly, a change to the warfarin administration time from 6 pm to 2 pm, supported by a poster campaign to increase
awareness of the problem. The objective of these changes was to reduce prescribing errors by reducing warfarin prescriptions out-of-hours, by
the on-call doctors. We repeated the audit cycle twice. Although our interventions were successfully introduced as shown in our second audit
cycle, the changes that were implemented were not sustained as shown in the third audit cycle. We identified a need for annual intervention to
educate new junior doctor staff to ensure that the positive outcomes achieved are maintained in the long term.
Problem
Dosing warfarin is a daily challenge and deranged international
normalised ratios (INRs) are a frequent occurrence in hospital
patients. This is likely due to a combination of acute illness,
interactions with other medications, changes in diet and exercise,
and inadequate prescribing knowledge. Errors in prescribing
leading to deranged INRs can have serious clinical implications and
put patients at risk of life-threatening haemorrhages or thrombosis.
In the UK warfarin is traditionally administered at 6 pm, and for
hospital inpatients this means that warfarin is inevitably prescribed
by an out-of-hours junior doctor. We sought to identify common
problems relating to the prescription and administration of warfarin
at our district general hospital and implement a service
improvement system to enhance the safety of patients admitted on
warfarin.
Background
Warfarin is the most prescribed oral anticoagulant in the UK (1).
Many of the patients admitted to hospital are on long term warfarin,
and we often observe fluctuations in their INR during their hospital
stay. Our project focuses on ways to improve warfarin prescribing
among junior doctors, one of the areas which we believe is having
on impact on the incidence of deranged INRs observed.
Baseline Measurement
We conducted a hospital-wide snapshot audit and analysed all
inpatient warfarin prescriptions during a 1 week period, excluding
patients on labour, paediatric, and dialysis wards. We analysed the
warfarin prescriptions through the review of the 10 components in
the oral anticoagulant section on the drug chart, to assess if they
were completed correctly. They included: indication, target INR,
duration, date started, name, route, time, signature, bleep, and
prescription date. We also surveyed the junior doctor staff through
the use of questionnaires. We focused on three main areas: level of
knowledge on prescribing warfarin; knowledge of local hospital
policies and guidelines with regard to warfarin prescribing; and the
proportion of warfarin prescriptions completed out-of-hours when on-
call. In addition, we collected laboratory data to evaluate the total
number of raised INRs above 5 over a 1 week period for all
inpatients. We excluded patients from the accident and emergency
department, those from the anticoagulant clinic, and those admitted
from the community with a raised INR. The cut-off value of 5 was
used because this is the value for which the risk of bleeding is
deemed high enough by the latest edition of the British Committee
for Standards in Haematology, such that explicit guidance is issued
(either withholding warfarin for 1-2 doses in INRs 5-8, or
administering oral vitamin K in INRs >8 in non-bleeding patients)
(2).
Our results showed that doctors had a low level of knowledge and
little confidence in prescribing warfarin. This led to components of
the warfarin prescription on the drug chart being left blank and
others completed by pharmacists. In addition, a considerable
proportion of warfarin prescriptions was made out-of-hours because
warfarin is usually administered at 6 pm. There were also no
hospital clinical guidelines to advise doctors on prescribing the
correct maintenance dose of warfarin, taking into account the
patient’s INR.
Design
Our findings were presented at the hospital’s Patient Safety Board’s
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meeting, and our proposed interventions were approved by senior
hospital management and physician representatives.
First, the warfarin administration time was changed to 2 pm to
enable the patient’s regular day team to prescribe the warfarin
instead of the on-call doctor. This was authorised by our pharmacy
department and all nursing, medical, and pharmacy staff were
made aware of the change. Secondly, we updated the hospital
warfarin prescribing guidelines in cooperation with one of the
haematology consultants. Thirdly, we increased junior doctor
awareness through a poster campaign.
Our project was conducted between March and November 2013
with the cycle being repeated twice following the implementation of
our interventions. Our third cycle was completed in November 2013,
to assess whether the changeover of new junior doctor staff in
August 2013 would adversely affect the positive outcomes that had
been achieved initially.
Strategy
Cycle 1 relates to our results obtained in March 2013. Out of a total
of 240 hospital inpatients, we analysed the warfarin prescriptions of
14 patients (23 patients had no drug chart available for analysis).
Our results revealed that, on average, 74% of the components on
the warfarin prescription were completed by doctors, 8% by
pharmacists, and 18% were left blank. The survey of junior doctors
revealed they were often called to prescribe warfarin when on-call
(mean 3 per shift) and there was a lack of guidance and education
about warfarin prescribing. Laboratory data revealed 20 cases of
raised INRs above 5 over a 1 week period in adult inpatients.
Cycle 2 relates to our results obtained in July 2013, following the
implementation of our interventions in May 2013. We analysed 22
warfarin prescriptions out of a total of 240 hospital inpatients.
Results revealed the successful transition of warfarin administration
time to 2 pm, with 100% of warfarin prescriptions being prescribed
for 2 pm. This correlated with a reduction in the number of out-of-
hours warfarin prescriptions by on-call junior doctors (mean <1 per
shift). Furthermore, warfarin prescription by doctors improved from
an average of 74% to 78%, although using a chi-squared analysis,
this was not a statistically significant change (p>0.5). However, in
both cycle 1 and cycle 2 there were significant outliers within the
data itself; in particular, “Start date” and “Duration” were persistently
poorly completed by doctors in both audit cycles, out of keeping
with the remainder of the chart. If these components are removed
and the results re-analysed, then an improvement from 73.1% to
90.3% is seen, which represents a significant improvement
(p<0.05). There was also a reduction in the number of raised INRs
above 5, with 11 cases over a 1 week period.
Cycle 3 relates to our results obtained in November 2013, following
the changeover of junior doctor staff. We analysed 20 warfarin
prescriptions out of a total of 253 hospital inpatients (30 patients
had no drug chart available for analysis). Results revealed a
statistically significant (p<0.05) decline both in terms of the
proportion of components of the warfarin prescription completed by
doctors (from 78% to 62%, with now 16% being completed by
pharmacists), and with regard to the warfarin administration time
with only 70% being administered at 2 pm. These results correlated
with an increase in the number of raised INRs above 5 over a 1
week period from 11 to 15 cases. Figure 1 illustrates the average
completion rates of the warfarin prescriptions for each audit cycle.
In each cycle, it was noted that a number of drug charts were not
available for review during data gathering. This was due to the drug
charts not being on the ward, often in the pharmacy. Given the
incidence of warfarin prescription being 7.6% on average across the
cycles, this would correlate with between 1-2 additional warfarin
prescriptions being unavailable for analysis within each audit cycle.
Results
The results of our analyses show that simple actions can be taken
to implement change. However, more work is needed to ensure that
these changes remain in place in the long term.
The warfarin prescription is not completed adequately by doctors,
and in all three cycles the components which were most often
missed included start date, and duration. This information is easily
found in the patient’s yellow book, which, in the UK, is used to
monitor warfarin dosage and INR fluctuations in the community. We
have concluded that by changing the prescribing time to 2 pm, this
ensures that the patient’s own team takes ownership for prescribing
and obtaining current information from the patient’s yellow book. It
also allows for the common situation when the patient’s blood tests
are omitted from the morning phlebotomy round. If this is noted at 2
pm there is still time to take a sample of the patient’s blood, check
the INR, and prescribe warfarin accordingly, before the patient’s
own team go off duty. The timing change repatriates the
responsibility of warfarin prescribing to the patient’s own team of
doctors. The components which are most frequently correctly
completed include name, route, time, and signature.
We have successfully introduced changes to increase the safety of
patients admitted on long term warfarin. Our results, however, show
the need for an annual “refresher” course for new junior doctors to
ensure we maintain the positive changes that were introduced.
See supplementary file: ds2982.pptx - “diagram for presentation
warfarin prescribing”
Lessons and Limitations
We have identified several limitations in our project, which may
have partly contributed to the poor outcomes observed in audit
cycle 3. Although we updated the hospital clinical guidelines on
prescribing warfarin following our first audit cycle, the guidelines are
not easily searchable on the intranet for use as a reference guide.
This is caused by the search facility selecting documents other than
clinical guidelines, meaning the new guidance was not easily found.
In addition, the e-learning module that we developed and planned
to introduce following the first audit cycle was not delivered before
our second or third audit cycles. Those planned changes will now
be implemented and we hope they will help to ensure that our initial
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actions will be sustained.
There was also the potential to have missed between 1-2 additional
warfarin prescriptions per audit cycle, if the average incidence of
warfarin prescriptions were applied to the drug charts not available.
Given the relatively low number of warfarin prescriptions within
each cycle, this could have an impact on the overall results seen.
However, given the high turnover and movements on/off wards, it
was not felt to be practical to review these missing charts at other
times, owing to the risk of potentially re-analysing the same chart
more than once (because to maintain anonymity, charts were
assigned to bed number only, not patient details).
Our actions were made possible by our Trust’s early phlebotomy
service which allows INR results to be made available in time for
the 2 pm warfarin prescription. Lack of this service in other trusts
could hinder the roll-out of this project.
Conclusion
Overall, our results show that improvement is possible with simple,
low cost measures. However, the changes that were introduced
require regular reinforcement to ensure they remain effective in the
long term. For this reason we propose annual education courses in
the form of a compulsory prescribing e-learning module for all new
junior doctor staff joining the Trust.
References
1. Cousins D, Harris W. Risk assessment of anticoagulant
therapy. London: NHS National Patient Safety Agency,
2006.
http://www.nrls.npsa.nhs.uk/easysiteweb/getresource.axd?a
ssetID=60022
2. . Keeling D, Baglin T, Tait C, et al. Guidelines on oral
anticoagulation with warfarin, 4th edn. British Committee for
Standards in Haematology, 2011.
http://www.bcshguidelines.com/documents/warfarin_4th_ed.
pdf
Declaration of interests
Nothing to declare
Acknowledgements
None
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warfarin
safety of patients admitted on long-term
Service improvement system to enhance the
Dana Warcel, Daniel Johnson, Neeraj Shah and Norman shreeve
doi: 10.1136/bmjquality.u202818.w1361
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Supplementary resource (1)

... Furthermore a previous quality improvement project carried out at another trust showed that changing the time of administration from 18:00 to 14:00 was associated with a reduction in the number of warfarin doses given out of hours [7]. ...
Article
Full-text available
Warfarin is frequently administered to hospital patients. The prescription and administration of this medication are particularly susceptible to error. Factors contributing to this include the narrow therapeutic index, patient-specific target range, and the need for regular INR monitoring. NICE guidelines state that warfarin should be given at the same time every day and the Bristol Royal Infirmary guidelines are warfarin to be given at 14:00. The 14:00 dosing ensures standardisation of administration; poor adherence to this recommendation may cause patient harm. We noticed that many warfarin doses were often given outside of maximal staffing hours and it was often left to the on call doctor to prescribe warfarin at erratic and inconsistent times. Our primary aim was to reduce the number of adverse outcomes associated with warfarin prescription and administration. We targeted two system measures: the proportion of warfarin administrations occurring within an hour of the 14:00 prescription and the proportion of INR results outside target range. We employed the model for improvement and carried out our project across seven acute medical wards. Baseline data showed that only 24% of doses were being given within an hour of the recommended time and 64% of doses were being given after 17:00 during minimal staffing hours. We successfully introduced a warfarin box within our trust which demonstrated an improvement in warfarin administration from 24% of patients receiving their warfarin within an hour of 14:00 to 49% and this was subsequently associated with a reduction in INRs above target range (23% to 9%).
Risk assessment of anticoagulant therapy. London: NHS National Patient Safety Agency
  • D Cousins
  • W Harris
Cousins D, Harris W. Risk assessment of anticoagulant therapy. London: NHS National Patient Safety Agency, 2006.
Guidelines on oral anticoagulation with warfarin, 4th edn. British Committee for Standards in Haematology
  • D Keeling
  • T Baglin
  • C Tait
Keeling D, Baglin T, Tait C, et al. Guidelines on oral anticoagulation with warfarin, 4th edn. British Committee for Standards in Haematology, 2011.