© 2010 Public Health Module Venue Date Unit: Public Health Aspects of Stroke.

© 2010

Public Health Module

VenueDate 

Unit: Public Health Aspects of Stroke

Aims of Unit

This unit of study will:• Explore how common strokes are and the evidence

of their impact on quality and length of life• Familiarise students with the major risk factors

for stroke• Explore the efficacy and ethics of interventions for the

prevention and management of strokes

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What is health?WB6

WHO Definition ‘a state of complete

physical, mental and social

well-being and not merely

the absence of disease

or infirmity’

Antonovosky: Salutogenic model

‘sense of coherence’

Seedhouse and Duncan: Achievement of potential

Empirical Lack of health

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What is public health?WB7

‘the science and art of preventing disease, prolonging life and promoting health through the organized efforts of society’

C.E.A. Winslow, 1920

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The wider determinants of health

Source: Dahlgreen and Whitehead, G and Whitehead M (1991)

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The challenge for public healthWB7

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Statistical description of nation’s healthWB8

Census data

Health Inequalities data

Infant Mortality Rates

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What is a stroke?

• A stroke is an interruption in the blood supply to the brain. Also known as cerebrovascular accident or CVA

• Usually because

1. Blood vessel has ruptured

2. Blood vessel blocked by a blood clot• Reduced blood supply results in

• Decreased oxygen/nutrient supply to the brain

• Damage to the brain tissue

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Types of stroke

There are two main types of stroke:

1. Ischaemic – caused by a blockage

(80% of all strokes)

2. Haemorrhagic – caused by a bleed

(20% of all strokes)

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Ischaemic Stroke

• Result of an obstruction blocking an artery carrying blood to the brain

• Causes include:

– Cerebral thrombosis – blood clot (thrombus) forms in a main artery – Cerebral embolus – obstruction caused by a blood clot, air bubble or

globule of fat (embolism) formed elsewhere in the body and carried to the brain

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Haemorrhagic Stroke

• Results of a burst blood vessel, causing haemorrhage into the brain

• Haemorrhagic stroke may result from:– Intra-cerebral haemorrhage where a blood vessel bursts within

the brain– Sub-arachnoid haemorrhage when a blood vessel on the surface

of the brain bleeds into the sub-arachnoid space between the brain and the skull

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Epidemiology of Stroke

• Around111,000 people have a stroke each year in the UK

• Second most common cause single cause of death in UK

• Significant numbers left with moderate or severe disabilities

• Stroke consumes 5% of all NHS costs

• Incidence has fallen by 40% over the past 20 years

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Modifiable Non-modifiable

Risk Factors for Stroke

• Diet• Raised cholesterol• Physical inactivity• Alcohol• High blood pressure• Smoking• Sleep apnoea• Obesity • Diabetes mellitis• Atrial Fibrillation • Previous Transient Ischaemic Attack

• Age• Gender• Ethnicity

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Preventing Stroke

In order to prevent stroke, we need to: 1. Understand factors associated with stroke2. Know how individual causal factors contribute to the aetiology

of stroke3. Understand these issues at both an individual and population level

Primary prevention: preventing disease in healthy individual and population

Secondary prevention: preventing the onset of stroke in patients with risk factors

Tertiary prevention: preventing the recurrence of stroke in patients who have previously had a stroke or TIA

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Methods of Prevention

Methods include:

• Controlling high blood pressure • Monitoring elevated blood cholesterol and controlling this

where appropriate• Prescribing drugs to thin the blood• Stopping smoking • Dietary improvements including avoiding excess fat, and

avoidance of excess alcohol intake• Maintaining a healthy weight • Exercising regularly• Optimising control of diabetes

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Epidemiological data and prevention

• Studies have demonstrated that the incidence of major stroke has fallen by 40% over the past 20 years (OXVASC)

• Stroke registers also hold a wealth of data on the descriptive epidemiology of stroke, as well as its natural history and impact

• Adequate data coverage and accuracy are crucial

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NHS Health Checks

• Preventative checks for those aged 40-74• Assess risk of vascular disease, including stroke

– Objective measurements (e.g. weight)– Self-reporting of lifestyle characteristics (e.g. smoking)

• Patients advised how to reduce their risk

Can an intervention like this really change behaviour?

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Symptoms of a stroke

Symptoms may include any of the following:

• Problems with speech

• Weakness or sensory loss on one side of the body

• Dizziness, nausea, balance and coordination problems

• Visual problems: loss or double vision

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Diagnosis of Stroke

• Head CT or MRI• ECG• Echocardiogram• Carotid Duplex• Heart Monitor• Cerebral angiography• Blood tests for cholesterol, glucose, clotting tendency etc

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Angiography

Severe narrowing of the internal carotid artery:

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Emergency Management

• Effectiveness of emergency management directly impacts outcome

• Ideally, patients transported direct to stroke unit– Rapid triage– Specialist clinicians– Rapid brain imaging

• Thrombolysis for ischaemic strokes – use of thrombolysis units

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Determinants of Prognosis

• Long term outcome depends on:

– Effectiveness of emergency intervention– Extent of damage to brain– Associated medical problems– Predisposition to recurrence (i.e. risk factors)

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Economic Cost of Stroke

• Stroke care costs the NHS approximately:– £7 billion per year in total– £2.9 billion in direct care costs

• 1 in 5 acute hospital beds and 1 in 4 long-term beds are occupied by stroke patients

• For each stroke patient, the cost to the NHS is around £15,000

over five years

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Economic Cost of Stroke

• Total societal costs (treatment + productivity losses) = £8.9 billion a year – 50% direct care costs – 27% informal care costs– 24% indirect costs

• Human, personal cost to stroke survivors and their families

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Quality of Life

• Individual’s perception of position in life in cultural, social, + environmental context

• Influenced by:– Physical– Material– Social– Emotional well-being– Personal development– Purposeful activity

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Quality of Life after a Stroke

• 1/3 will be left with significant disabilities • Measurement of health status must include an estimation of

well being • Important factors include disability, depression, age and

social support

• Depression is also a common consequence of stroke

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Targets for 2010: under 75 rates met

National Stroke Strategy 10 point plan for action

Government strategies for stroke

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SummaryWB26

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