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Audit of anti-platelet and anti-coagulation prophylaxis in the secondary prevention of ischaemic cardiac events

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 REASON FOR CHOICE OF AUDIT

 I chose to audit the use of anti-platelet and anti-coagulant therapy in the secondary prevention of ischaemic cardiac events at Well Close Square Surgery as: -

 

1.       People with a history of Acute Myocardial Infarction (MI) are at high risk of further ischaemic cardiac events carrying a high rate of morbidity and mortality. Antiplatlet and anticoagulant therapy has been shown to reduce the risk of further ischaemic events [1,2,3,4].

 

2.       This is a highly computerised practice, which regularly undertakes its own internal audit.  The use of anti-platelet therapy in patients with ischaemic heart disease had initially been audited five years ago in 1996/1997, the loop having been completed in 2000 and I was interested to see how the practice compared now to then.

 

3.       Since the initial audit, a computerised template has been introduced with annual reviews of patients with ischaemic heart disease.  At present this only addresses whether a patient is on Aspirin or Warfarin.  Other anti-platelet drugs are not currently considered.

 

4.       The practice takes pride in being paperless, and I was also interested to see if data was recorded in an accessible fashion within the computerised network.

 

CRITERIA CHOSEN

 The criterion chosen was: -

 Patients with previous myocardial infarction should be on either Antiplatelet or Anticoagulant prophylaxis unless contraindicated.

 The reason for this are: -

 1.         75% of patients with a previous MI are at moderate to high risk of further ischaemic cardiac events [1].

 2.         A recent analysis suggests that oral anticoagulants, i.e. Warfarin, substantially reduce the risk of vascular events in the absence of anti-platelet therapy [2]. 

 3.         Aspirin reduces the risk of serious vascular events in people at risk of either ischaemic cardiac events [3,4].

 4.         Clopidogrel is an alternative anti-platelet regime to Aspirin and though no more effective than Aspirin, trials have suggested that it also can decrease the risk of further vascular events [5].

 A patient was deemed to be taking a medicine (Warfarin, Aspirin, or Clopidogrel) if a prescription had been issued in the last 180 days, this reflects repeat prescribing practices at the surgery.  The exception to this was Aspirin as some patients take it ‘Over The Counter’ (OTC), if this was recorded in the notes, then they were included as taking Aspirin.

 Patients who have a record of contraindication to Aspirin were excluded from the group of patients not receiving prophylaxis; this was to make results comparable to previous audits carried out in the Practice.

 Patients on other anti-platelet therapies were not included.  This was because Ticlopidine is not on the practice formulary though is licensed for secondary prevention in people with ischaemic heart disease.  Dipyridamole is also not included as this only has a licence for secondary prevention of ischaemic stroke and TIAs, not IHD [6]. 

STANDARDS SET

A standard of 98% of patients with a previous MI being on Warfarin, Aspirin or Clopidogrel, or having a record that this was contraindicated was set.

A 98% standard was set because: -

1.                   Local PMS sets a standard of 80% that all patients with coronary artery disease/TIA or peripheral vascular disease should be in receipt of Aspirin.  All practices achieved this standard with ease.  Many of the practices being well above 90%.

2.                   Audits conducted within the practice in 1996/1997 achieved a rate of 93% of patients with a read code of IHD having a record of Aspirin prophylaxis or contra-indication.  At this time a standard of 98% was suggested as an appropriate target.  When the cycle was repeated in March 2000; this time including patients on Warfarin; the overall achievement was only 94%.

3.                   All patients with IHD are reviewed annually by the practice nurses if they are able to attend the surgery, or if house bound by the district nurses, this review follows a previously agreed protocol. This includes prompts to check if patients are on Warfarin or Aspirin, to initiate Aspirin if appropriate and record whether therapy is contraindicated. Given all patients should have had at least one annual review since the audit was last performed the pre existing standard of 98% was kept

PREPARATION AND PLANNING

 The following preparation and planning was undertaken, with input from a variety of members of the primary health care team: -

 1.                   The audit was discussed with my trainer and the other partners at the practice who felt that it would be worthwhile re-auditing this area.

 2.                   A session was spent with the nurse practitioner who helps carry out much of the ischaemic heart disease reviews and was instrumental in developing the current computer driven pro-forma for this review.

 3.                   The topic was also discussed at a practice clinical meeting at which the partners, practice nurses and district nurses were all present. 

 4.                   With the help of my trainer the various computer read codes where identified for patients with:-

a.                   MI ever.

b.                   Prescription for asprin, warfrin or clopidogrel in last 180days.

c.                   OTC asprin.

d.                   Contraindication to salicylates or asprin

 5.                   The data collections were performed using computer searches, the practice IT specialist helped in performing these searches. 

DATA COLLECTION 1

The first data collection was performed on the 9th August 20002.

 

Patients with MI ever

211

 

anticoagulant or antiplatlet prescription

169

OTC asprin

18

asprin contraindicated

5

TOTAL

192 

 

Of the 211 patients with a record of MI, nineteen have no computerised records of taking antiplatlet or anticoagulant prophylaxis; nor a contraindication to these.

 

This is an achievement of 91%.

 

The standard of 98% was not achieved.

CHANGES TO BE EVALUATED

Given the small number of patients involved a pro-active approach was taken.  The computer records of all nineteen patients were viewed by myself and then the patient discussed with their named principal.

Three patients were found to be deceased and one to have moved from the area.  These patients details were removed from the computer system.

If it was felt appropriate for the patients to be on either Warfarin or Aspirin, the patient was initially contacted via telephone, either by their own GP or me.  A few of the patients were deemed to be inappropriate for treatment for a variety of reasons: one was suffering advanced lung carcinoma and another from advanced dementia and refusing all oral medication, these patients were not contacted.

At the initial telephone consultation, it became apparent that some patients were taking OTC asprin, or that antiplatlet treatment was contraindicated; their records were updated accordingly.

When patients were approached by telephone, it was explained to them that anti-platelet therapy such as Aspirin was beneficial for people such as themselves and could reduce the risk of a further significant ischaemic event such as a heart attack.  Given this information if the patient choose to commence Aspirin this was done.  If they wanted to discuss things further or required more information, they were offered a consultation at the surgery or a home visit depending on circumstances.  Their notes were updated accordingly.

DATA COLLECTION 2

Data was collected again on 14th October 2002.  The results were:

CONCLUSIONS

The practice is highly computerised and undertakes regular audit in many different areas of clinical practice. Standards in this area set two years earlier were not being met, the reasons identified for this are:  

1.         Problems with record keeping: -

a.         Deceased patients and patients having moved from the area but not having been removed from the computer system (4 patients).

            b.         Use of OTC asprin not having been recorded.

            c.         Contraindication to Aspirin not recorded.

2.                   The audit cycle not having been completed for 2yrs

3.                   Deficiencies in the current template used for IHD annual review.

Having now achieved a good rate of antiplatlet or antithrombotic prophylaxis, it is important to try and maintain this standard.

After discussion at the practice multidisciplinary meeting the following proposals for change have been or are in the process of being implemented: -

1.                   Twice yearly search to remove deceased patients from active computer records.

2.         Changes to IHD annual review template.  This will now: -

a.                   Prompt to consider the use of Clopidogrel in patients not using Warfarin or Aspirin.

b.                   Prompt to ask if Aspirin is contraindicated, and the reason why, again this will automatically generate the appropriate read code.

c.                   A prompt to ask if OTC Aspirin is being used, if answered yes this will automatically enter the appropriate read code.

3.         Yearly completion of the Audit cycle.

With these changes in mind the audit cycle should be completed again in one year when a standard of 98% would still be appropriate.

REFERENCES

1.                   The Multicenter Postinfarction Research Group. Risk stratification and survival after myocardial infarction. N Engl J Med 1983;309;331-336.

2.                   Anand SS, Yusuf S. Oral anti-coagulant therapy in patients with coronary artery disease: a meta-analysis.  JAMA 1999; 282:2058-2067.

3.                   Antiplatelet Trialists' Collaboration.  Collaborative overveiw of randomised trials of antiplatlet therapy -I:prevention of death, myocardial infarction, & stroke by prolonged antiplatlet therapy in various categories of patients. BMJ 1994;308:81-105.

4.                   Fallen E, Cairns J, Dafoe W, et al.  Management of the post myocardial infacrtion patient: a consensus report – revesion of the 1991 CCS guidelines. Can J Cardiol 1995;11:477-486.

5.                   CAPRIE Steering Committee.  A randomised, blinded, trial of clopidogrel versus asprin in patients at risk of ischaemic events.  Lancet 1996;348:1329-1339.

6.                   BNF, Section 2.9

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