Stroke and Transient Ischaemic Attacks (TIA)

Stroke/TIA - Rationale for Inclusion of Indicator Set
Stroke is the third most common cause of death in the developed world. One quarter of stroke deaths occur under the age of 65. There is evidence that appropriate diagnosis and management can improve outcomes.

Stroke Indicator 1
The practice can produce a register of patients with Stroke or TIA

Stroke 1.1 Rationale
A register is a prerequisite for monitoring patients with stroke or TIA.

For patients diagnosed prior to April 2003 it is accepted that various diagnostic criteria may have been used. For this reason the presence of the diagnosis of stroke or TIA in the records will be acceptable. However, practices may wish to review patients previously diagnosed and if appropriate attempt to confirm the diagnosis.

As with other conditions, it is up to the practice to decide, on clinical grounds, when to include a patient, eg when a 'dizzy spell' becomes a TIA.

Stroke 1.2 Preferred Coding
Haemorrhagic Stroke - G61%
Non-haemorrhagic Stroke - G64%
TIA - G65%

Stroke 1.3 Reporting and Verification
The practice reports the number of patients on its stroke/TIA disease register and the number of patients on its stroke/ TIA register as a proportion of total list size.

Verification - PCOs may compare the expected prevalence with the reported prevalence.

Stroke Indicator 2
The percentage of new patients with presumptive stroke (presenting after 1 April 2003) who have been referred for confirmation of the diagnosis by CT or MRI scan

Stroke 2.1 Rationale
Randomised trials of the use of CT brain scanning have not been performed, but a clinical consensus exists that assessment of most patients with acute cerebrovascular events should include CT or MRI brain scanning because:

- Specific treatment of intracranial haemorrhage (eg neurosurgery, cessation/reversal of antithrombotic therapies) may be indicated if rapidly diagnosed
- There is conclusive evidence for the efficacy of antiplatelet therapy and anticoagulant agents in the secondary prevention of ischaemic stroke, but these drugs should be avoided in cases of haemorrhagic stroke
- Clinical scoring systems have been found to be unreliable in distinguishing ischaemic and haemorrhagic stroke.

Grade C Recommendation SIGN 13

Further information: http://www.sign.ac.uk/pdf/sign13.pdf

SIGN guideline 13 emphasises the importance of timing CT scanning, preferably within 48 hours and no later than seven days after an acute stroke. The diagnosis of stroke will often be made in secondary care and has to take account of locally based services.

TIAs (ie focal neurological symptoms which resolve within 24 hours) are almost invariably ischaemic in nature. Although CT or MRI scan can be helpful in managing TIA it is not considered essential that TIA patients receive a CT or MRI scan.

Stroke 2.2 Preferred Coding
CT Scan - 5674
MRI (abnormal) - 5693
MRI (normal) - 5692

Stroke 2.3 Reporting and Verification
The practice should report those patients who have been referred for a CT scan or MRI scan within 12 months of being added to the register in whom a new diagnosis of stroke has been made since 1 April 2003.

In verifying that this information has been correctly recorded, a number of approaches could be taken by a Primary Care Organisation:

1. Inspection of the output from a computer search that has been used to provide information on this indicator
2. Inspection of a sample of records of patients with stroke diagnosed after 1 April 2003 to look at the proportion with CT or MRI scan
3. Inspection of a sample of records of patients for whom a record of CT or MRI scan is claimed, to see if there is evidence of this in the medical records.

Stroke Indicator 3
The percentage of patients with TIA or stroke who have a record of smoking status in the last 15 months, except those who have never smoked where smoking status should be recorded at least once since diagnosis

Stroke 3.1 Rationale
There are few randomised clinical trials of the effects of risk factor modification in the secondary prevention of ischaemic or haemorrhagic stroke. Inferences can be drawn from the findings of primary prevention trials that cessation of cigarette smoking should be advocated.

Grade C Recommendation SIGN 13

Further information: http://www.sign.ac.uk/pdf/sign13.pdf

Stroke 3.2 Preferred Coding
Never Smoked - 1371
Ex Smoker - 137L
Smoker - 137R

Stroke 3.3 Reporting and Verification
The aim of this indicator is to ensure that the smoking status of all patients is known in the previous year, making the assumption that patients who have never smoked will continue not to smoke (in order to avoid keeping asking them).

The numerator of the indicator is the number of stroke/TIA patients who have never smoked plus the number who have been recorded as ex- or current smokers in the past 15 months. The denominator is the total number of stroke/TIA patients. Thus:

Stroke Indicator 4
The percentage of patients with a history of TIA or stroke who smoke and whose notes contain a record that smoking cessation advice or referral to a specialist service, if available, has been offered in the last 15 months

Stroke 4.1 Rationale
Smoking cessation evidence has mostly been investigated in the domain of ischaemic heart disease (IHD). Many strategies have been used to help people to stop smoking. A meta-analysis of controlled trials in patients post myocardial infarction showed that a combination of individual and group smoking cessation advice, and assistance reinforced on multiple occasions - initially during cardiac rehabilitation and reinforced by primary care teams - gave the highest success rates.

Reference Grade B recommendation SIGN Guidelines 41/51

Further Information: http://www.sign.ac.uk/guidelines/fulltext/51/index.html
Further Information: http://www.sign.ac.uk/guidelines/fulltext/41/index.html

A number of studies have recently shown benefits from the prescription of nicotine replacement therapy or buproprion in patients who have indicated a wish to quit smoking. Further guidance is available from NICE.

Further Information: http://www.nice.org.uk/pdf/NiceNRT39GUIDANCE.pdf

In a significant number of PCOs across the UK specialist smoking cessation clinics are now available. Referral to such clinics, where they are available, can be discussed with patients. This should also be recorded as smoking cessation advice.

Stroke 4.2 Preferred Coding
Smoking Cessation Advice 8CAL

Stroke 4.3 Reporting and Verification
The practice should report the percentage of patients on the stroke/TIA register who are current smokers who have been offered smoking cessation advice in the last 15 months.

Stroke Indicator 5
The percentage of patients with TIA or stroke whose notes have a record of blood pressure in the preceding 15 months

Stroke 5.1 Rationale
All patients should have their blood pressure checked and hypertension persisting for over one month should be treated. The British Hypertension Society Guidelines are: optimal blood pressure treatment targets are systolic pressure less than or equal to 140 mmHg and diastolic blood pressure (DBP) less than or equal to 85 mmHg. The proposed audit standard is less than or equal to 150/90.

In one major overview, a long-term difference of 5-6 mm Hg in usual DBP is associated with about 35-40% less stroke over five years. (Collins et al. Lancet 1990; 335: 827-38).

Grade A Recommendation RCP Stroke Guideline 2002

Further information: http://www.rcplondon.ac.uk/pubs/books/stroke/ceeu_stroke_clinical11.htm#113

Stroke 5.2 Preferred Coding
Examination of BP 246.

Stroke 5.3 Reporting and Verification
Practices should report the percentage of patients on the stroke/TIA register who have had a blood pressure recorded in the last 15 months.

Stroke Indicator 6
The percentage of patients with a history of TIA or stroke in whom the last blood pressure reading (measured in last 15 months) is 150/90 or less

Stroke 6.1 Rationale
See Stroke 5.1.

Stroke 6.2 Preferred Coding
Blood Pressure numeric value

Stroke 6.3 Reporting and Verification
Practices should report the percentage of patients on the stroke/TIA register in whom the last recorded blood pressure in the last 15 months was 150/90 or less.

Stroke Indicator 7
The percentage of patients with TIA or stroke who have a record of total cholesterol in the past 15 months

Stroke 7.1 Rationale
There is evidence for benefit in reducing cholesterol in ischaemic stroke and TIA. The issue around potential harm in haemorrhagic stroke is more controversial (Oliver MF. Cholesterol and strokes. BMJ 2000; 320: 459-460).

GJ Hankey reviewed the evidence in terms of establishing the role of cholesterol-modifying therapy in stroke prevention. This paper states "Population-based observational cohort studies show a variable weak positive relationship between increasing plasma total cholesterol concentrations and an increasing risk of ischaemic stroke, which is partly offset by a weaker negative association between decreasing total cholesterol concentrations and an increasing risk of haemorrhagic stroke.

However, randomised controlled trials show unequivocally that lowering plasma total cholesterol by approximately 1.2 mmol/l (and LDL-cholesterol by 1.0 mmol/l) is associated with a reduced relative risk of stroke and other serious vascular events by at least a quarter, and probably a third, without any increase in haemorrhagic stroke, in a wide range of men and women (including individuals with previous stroke).

The proportional reduction in stroke risk is consistent, irrespective of the patient's age, baseline plasma cholesterol concentration, and absolute risk of stroke (although perhaps less in very low-risk individuals), but is increased with greater degrees of cholesterol lowering (15% or more), and thus with statin medications, which are more potent than non-statin interventions in lowering cholesterol levels.

The absolute reduction in stroke risk achieved by statins is greatest among individuals at highest risk of stroke. Preliminary evidence suggests that lowering total cholesterol levels by diet may be an effective adjunctive therapy to statins, and raising plasma HDL-cholesterol concentrations among patients with coronary heart disease and low HDL-cholesterol levels ( 1 mmol/l) by means of gemfibrozil may also effectively prevent stroke. In summary statin drugs are effective and safe in preventing initial and recurrent stroke." (Curr Opin Lipidol 2002 Dec;13(6):645-51)

Given the vast majority of strokes and TIAs are ischaemic in origin, it is proposed that this indicator is applied. In recognition that where there is a proven haemorrhagic stroke clinicians may wish to weigh up the risks for the patient, the payment levels have been set at a lower level.

Stroke 7.2 Preferred Coding
Serum cholesterol 44P%

Stroke 7.3 Reporting and Verification
Practices should report the percentage of patients on the stroke/TIA register who have a record of total cholesterol in the last 15 months.

In verifying that this information has been correctly recorded, a number of approaches could be taken by a Primary Care Organisation:
1. Inspection of the output from a computer search that has been used to provide information on this indicator
2. Inspection of a sample of records of patients with stroke/TIA to look at the proportion with recorded serum cholesterol
3. Inspection of a sample of records of patients with stroke/TIA for whom a record of serum cholesterol is claimed, to see if there is evidence of this in the medical records.

Stroke Indicator 8
The percentage of patients with TIA or stroke whose last measured total cholesterol (measured in last 15 months) is 5 mmol/l or less

Stroke 8.1 Rationale
See Stroke 7.1.

Stroke 8.2 Preferred Coding
Cholesterol numeric value

Stroke 8.3 Reporting and Verification
Practices should report the percentage of patients on the stroke/TIA register who have a record of total cholesterol in the last 15 months which is 5mmol/l or less.

In verifying that this information has been correctly recorded, a number of approaches could be taken by a Primary Care Organisation:
1. Inspection of the output from a computer search that has been used to provide information on this indicator
2. Inspection of a sample of records of patients with stroke to look at the proportion with recorded serum cholesterol of 5mmol/l or less
3. Inspection of a sample of records of patients for whom a record of serum cholesterol of 5mmol/l is claimed, to see if there is evidence of this in the medical records.

Stroke Indicator 9
The percentage of patients with a stroke shown to be non-haemorrhagic, or a history of TIA, who have a record that aspirin, an alternative anti-platelet therapy, or an anti-coagulant is being taken (unless a contraindication or side-effects are recorded)

Stroke 9.1 Rationale
Long-term antiplatelet therapy reduces the risk of serious vascular events following a stroke by about a quarter. Antiplatelet therapy, normally aspirin, should be prescribed for the secondary prevention of recurrent stroke and other vascular events in patients who have sustained an ischaemic cerebrovascular event.

Grade A recommendation SIGN 13

Further information: http://www.sign.ac.uk/pdf/sign13.pdf

All patients who are not on anticoagulation should be taking aspirin (50-300mg) daily, or a combination of low-dose aspirin and dipyridamole modified release(MR). Where patients are aspirin-intolerant an alternative antiplatelet agent (clopidogrel 75mg daily or dypyridamole MR 200mg twice daily) should be used.

Grade A Recommendation RCP Stroke Guideline

Further information: http://www.rcplondon.ac.uk/pubs/books/stroke/ceeu_stroke_clinical11.htm#113

Warfarin should be considered for use in patients with non-valvular atrial fibrillation.

Grade A recommendation SIGN 13

Stroke 9.2 Preferred Coding
OTC Aspirin 8B3T

Other drugs will be prescribed and picked up on drug search.

Medication stopped, interaction 8BI6
Aspirin prophylaxis contraindicated 8I24.
Warfarin contraindicated 8I25.
Adverse reaction to warfarin TJ421
Adverse reaction to salicylates TJ53.
History of aspirin allergy ZV148

Stroke 9.3 Reporting and Verification
Practices should report the percentage of patients with non-haemorrhagic stroke or TIA who have a record in the last 6 months of prescribed aspirin, clopidrogel, dypiridamole or warfarin or of taking OTC aspirin.

Stroke Indicator 10
The percentage of patients with TIA or stroke who have a record of influenza immunisation in the preceding 1 September to 31 March

Stroke 10.1 Rationale
This is a current recommendation from the Departments of Health and the Joint Committee on Vaccination and Immunisation (www.doh.gov.uk/greenbook/).

Stroke 10.2 Preferred Coding
Flu Vaccination given 65E

Flu vac contra-indicated 8I2F.

Stroke 10.3 Reporting and Verification
The percentage of patients on the stroke/TIA register who have had an influenza vaccination administered in the preceding 1 September to 31 March.