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Stroke risk assessment CHADS2 score of 1 Recorded in the preceding 15 months,

38DE. Congestive heart failure, hypertension, age, diabetes, stroke 2 risk score - Score of 1

Anti-coagulant drug therapy or an anti-platelet drug therapy (Prescribed after 1st October, i.e. in previous 6 months)

Salicylate contra-indications: persistent

14LK. H/O: aspirin allergy
ZV148 [V]Personal history of aspirin allergy
U6051 [X]Salicylates causing adverse effects in therapeutic use
TJ53. Adverse reaction to salicylates

Salicylate contra-indications: expiring (12 months)

8I24. Aspirin prophylaxis contra-indicated
8I38. Aspirin prophylaxis refused
8I66. Aspirin not indicated
8I70. Aspirin not tolerated

Warfarin contraindications: persistent

14LP. H/O: warfarin allergy
TJ42. Adverse reaction to anticoagulants
TJ421 Adverse reaction to warfarin sodium
TJ422 Adverse reaction to nicoumalone
TJ423 Adverse reaction to phenindione
TJ42z Adverse reaction to anticoagulants NOS
U6042 [X]Anticoagulants causing adverse effects in therapeutic use
ZV14A [V]Personal history of warfarin allergy

Warfarin contraindications: expiring (12 months)

8I25. Warfarin contraindicated
8I3E. Warfarin declined
8I65. Warfarin not indicated
8I71. Warfarin not tolerated
8I2R. Anticoagulation contraindicated
8I3d. Anticoagulation declined
8I6N. Anticoagulation not indicated
8I7A. Anticoagulation not tolerated
8I2o. Dabigatran contraindicated
8IES. Dabigatran declined
8I611 Dabigatran not indicated
8I7R. Dabigatran not tolerated
8I2u. Novel oral anticoagulant contraindicated
8IH1. Novel oral anticoagulant declined
8I6s. Novel oral anticoagulant not indicated
8I7V. Novel oral anticoagulant not tolerated

Clopidogrel contraindications: persistent

14LQ. H/O: clopidogrel allergy
U6048 [X]Clopidogrel causing adverse effects in therapeutic use
ZV14B [V]Personal history of clopidogrel allergy

Clopidogrel contraindications: expiring (12 months)

8I2K. Clopidogrel contraindicated
8I3R. Clopidogrel declined
8I6B. Clopidogrel not indicated
8I72. Clopidogrel not tolerated

Dipyridamole contraindications: persistent

14LX. H/O: dipyridamole allergy
TJC44 Adverse reaction to dipyridamole
U60C3 [X]Coronary vasodilators causing adverse effects in therapeutic use, not elsewhere classified

Dipyridamole contraindications: expiring (12 months)

8I2b. Dipyridamole contraindicated
8I3n. Dipyridamole declined
8I6a. Dipyridamole not indicated
8I7J. Dipyridamole not tolerated

OTC salicylate codes ( in last 6 months (v10))

67I8. Advice about taking aspirin
8B63. Salicylate prophylaxis
8B3T. Over the counter aspirin therapy

Salicylate prescription codes (prescribed in last 6 months (v10))


Clopidogrel prescription codes (prescribed in last 6 months (v10))

8B6P. Clopidogrel prophylaxis (v23)

Warfarin prescription codes (prescribed in last 6 months (v10))

8B2K. Anticoagulant prescribed by third party

Dipyridamole prescription codes (prescribed in last 6 months (v10))

bu1..% (excluding bu13., bu1z.)


AF 005.1 Rationale

Atrial fibrillation is the most common sustained cardiac arrhythmia and if left untreated is a significant risk factor for stroke and other morbidities.

There is evidence that stroke risk can be substantially reduced by warfarin (approximately 66 per cent risk reduction) and less so by aspirin (approximately 22 per cent risk reduction).

To help clinicians decide which management path to choose, several tools have been developed to estimate the risk of stroke on the basis of clinical factors. The scoring system recommended for QOF is CHADS2, which is validated and particularly suitable for identifying high-risk AF patients, while also being relatively simple to use. The CHADS2 system is based on the AF Investigators I Study (AFI1) and Stroke Prevention in AF I Study (SPAF1) risk criteria

The revised CHADS2 system scores one point, up to a maximum of six, for each of the following risk factors (except previous stroke or TIA, which scores double, hence the 2)

1. C - Congestive HF (One Point)

2. H - Hypertension (One Point)

3. A - Age 75 or Over (One Point)

4. D - Diabetes Mellitus (One Point)

5. S2 - Previous strke or TIA (Two Points)

A score of zero is classified as low risk, one is moderate risk and two or more is high risk.

Evidence from the Birmingham Atrial Fibrillation Treatment of the Aged (BAFTA) and Atrial fibrillation Clopidogrel Trial with Irbesartan for prevention of Vascular Events (ACTIVE-W) studies suggests that not only is warfarin more effective than aspirin, but that it is not as unsafe (in terms of risk of serious haemorrhage) as previously thought. For example, in the BAFTA trial, the relative risk (RR) for stroke for patients treated with anti-coagulation versus aspirin was 046 (95% confidence interval [CI] 026 to 079). The same study showed no significant difference in the rate of haemorrhage between the warfarin and aspirin arms of the study (RR 088, 95% CI 046 to 163), which suggests a shift in the balance between the risks and benefits of warfarin compared with aspirin. However, to date no meta-analysis has been identified combining the results of studies comparing the two treatments for the outcome of haemorrhage.

Anti-coagulation would not necessarily be indicated if the episode of atrial fibrillation was an isolated event that was not expected to re-occur (for example, one-off atrial fibrillation with a self-limiting cause).

This indicator uses the CHADS2 risk stratification scoring system to inform treatment options.The use of a risk stratification scoring system is in line with European Society of Cardiology (ESC) (2010) guidance that states that recommendations for therapy should be based on the presence (or absence) of risk factors for stroke and thromboembolism.

Where the CHADS2 score is 0 (low risk), then the patient can be offered treatment with aspirin. Where the CHADS2 score is 1 (moderate risk) then either aspirin or anti-coagulants can be offered.

AF 005.2 Reporting and verification

See indicator wording for requirement criteria.

The Business Rules will look for the latest CHADS2 score in the patient record and if the score is 1, the patient is eligible for inclusion in the denominator.



No authors listed (1994) Risk factors for stroke and efficacy of antithrombotic therapy in atrial fibrillation: analysis of pooled data from five randomized clinical trials. Archives of Internal Medicine 154: 1449-57

Mant J, Hobbs FD, Fletcher K et al. (2007) Warfarin versus aspirin for stroke prevention in an elderly community population with atrial fibrillation (the Birmingham Atrial Fibrillation Treatment of the Aged Study, BAFTA): a randomised controlled trail. Lancet 370: 493-503

Healey JS, Hart RG, Pogue J et al. (2008) Risks and benefits of oral anticoagulation compared with clopidogrel plus aspirin in patients with atrial fibrillation according to stroke risk: the Atrial fibrillation Clopidogrel Trial with Irbesartan for prevention of Vascular Events (ACTIVE-W). Stroke 39: 1482-6

Guidelines for the management of atrial fibrillation The Task Force for the Management of Atrial Fibrillation of the European Society of Cardiology (ESC) (2010). European Heart Journal 31: 2369-429. Available from www.escardio.org/guidelines-surveys/esc-guidelines/GuidelinesDocuments/guidelines-afib-FT.pdf



Prepared By Jean Keenan