Dr. Yoga NathanSenior Lecturer in Public Health

GEMS UL

Risks & Trends Asthma trends in Ireland & GloballyPrevalence Risk Pyramid

Consider ways to measure rates and trends of disease and apply them to asthma management

Estimate the prevalence of asthma in Ireland.

Construct a 'risk pyramid'.

.

Risk can be defined as “the threat or probability that an action or event will adversely or beneficially affect an organization's ability to achieve its objectives”.

In simple terms risk is ‘Uncertainty of Outcome’, either from pursuing a future positive opportunity, or an existing negative threat in trying to achieve a current objective.

In statistics and mathematical epidemiology, relative risk (RR) is the risk of an event (or of developing a

disease) relative to exposure.

Relative risk is a ratio of the probability of the event occurring in the exposed group versus a non-exposed group.

The relative risk is the risk ratio because it is the ratio of the risk in the exposed divided by the risk in the unexposed. In a simple comparison between an experimental group and a control group:

A relative risk of 1 means there is no difference in risk between the two groups.

An RR of < 1 means the event is less likely to occur in the experimental group than in the control group.

An RR of > 1 means the event is more likely to occur in the experimental group than in the control group.

Risks Published studies e.g. ISAAC

(International Study of Asthma and Allergies in Childhood)

and unpublished studies The effect of prior atopic illness, was largely explained

by the strong independent association of incidence of asthma and wheezy bronchitis with atopic disease at the end of each incidence period

Genetic Family History Twin Studies

Environmental Antenatal/Neonatal

Maternal smoking ?in utero/post natal nutrition Neonatal illness

House dust mite exposure Parental smoking Lower socioeconomic group Pets Air pollutants Climate Diet Hygiene Hypothesis

Allergens: animals, house dust mite, mould spores, pollen etc

Infection Air pollution: Indoor and outdoor Physical stimuli: cold air Exercise Emotional factors Chemicals: e.g. Tartrazine dye Drugs: e.g. Aspirin

Trend estimation is a statistical technique to aid interpretation of data.

When a series of measurements of a

process are treated as a time series, trend estimation can be used to make and justify statements about tendencies in the data

TrendsIncidence dataPrevalence dataMorbidity dataMortality dataNational and International data

Incidence data In Ireland no routine collection of this data Potential sources:

• GP databases• Specially collected data

Prevalence data ISAAC National studies Local studies

Hospital In-patient Enquiry (HIPE) Public Health Information System (PHIS) Health Atlas Ireland Central Statistics Office (CSO)

Between 60 and 80 people die in Ireland each year from asthma (30% of these are under 40 years of age

Costs of Asthma in Ireland (Direct and Indirect Costs):

In 2003 asthma cost the State €463m in total

Prevalence of diagnosed asthma

Wheeze in past 12/12

ISAAC Ireland (13-14 years) (1)

Phase One 1992-1998

Phase Three 1999-2004

 

29.1%

26.7%

Ireland (13-14 years) (2)

 1995

 1998

 2003

15.2%

18.2%

21.6%

29%

29.8%

26.7%

Ina Kelly Thesis (13-14 years)

Midlands 2007 (3)

23.5% 32.6%

Combined Clarecastle/Ennistymon group all ages 2007/2008

17.1% 29.1%

0

100

200

300

400

500

600

1998 1999 2000 2001 2002 2003 2004 2005 2006

Num

bers

Year

PHIS asthma inpatient episodes Mid-West

Age0-14

Age 15+

All

National trends for asthma inpatient episodes

0

1000

2000

3000

4000

5000

6000

7000

1998 1999 2000 2001 2002 2003 2004 2005 2006

Year

nu

mb

ers age0-14

Age 15+

All

These studies demonstrates a sizable persisting level of childhood asthma in the Irish population and in addition there has been an overall upward trend for asthma prevalence.

This represents a 42% relative increase in Irish childhood asthma diagnosis from the period 1995 to 2002-3.

There was however, a relative drop in reported wheeze in these children by over 10%.

The cause for these trends is unknown but may reflect better recognition and diagnosis of asthma in clinical practice, reduced childhood asthma admissions to hospital and the drop in reported wheezing rates in the Irish population from 1998 to 2002-3 would be supportive of this.

These changes have coincided with the launch and the wide dissemination of national evidence-based Asthma Management Guidelines.

Ireland has the 4th highest prevalence of asthma worldwide

Ireland has highest rate (with UK) in EU About 470,000 Irish population have asthma

(1 in 8 of population) Four (4) fold increase in Childhood asthma

from 1984-2003 Asthma is the most common chronic disease

in children and young adults

Lifestyle changes (indoors) Increased atopy (influenced by

pollution) Diet changes (reduced breast feeding,

lowered antioxidant intake, increased salt)

Reduced exposure to childhood illness

Results of WHO surveys: The existing burden of asthma and other

allergic diseases in developing countries was significant.

The prevalence of asthma in developing countries was likely to increase with industrialisation and Westernisation.

Some 235 million people currently suffer from asthma. It is the most common chronic disease among children

Big Picture Increasing prevalence of diagnosed asthma

Decreasing prevalence of asthma symptomsHigh prevalence in English speaking world with

downward trendLow prevalence in many developing countries with

upward trend Decreasing hospital discharges for diagnosis of

asthma Decreasing number of MORTALITY from

asthma

Increasing prevalence of diagnosed asthma ?Real ? Changing diagnostic criteria May be related to increased awareness by

GPs Public

Decreasing prevalence of symptoms ? Increased numbers being diagnosed may mean more

people on adequate treatment

Worldwide prevalence of clinical asthma

Braman S S Chest 2006;130:4S-12S©2006 by American College of Chest Physicians

Asthma case fatality rates worldwide (deaths/100,000 cases)

Braman S S Chest 2006;130:4S-12S©2006 by American College of Chest Physicians

Despite international consensus on asthma management , patterns of asthma prescribing &

asthma diagnosis frequency by GP vary considerably. If prescribing were more in concordance with

published guidelines, one would expect more consistent asthma treatment, minimal antibiotic use and no prescribing of drugs of limited clinical value.

The variation in proportions of patients with asthma suggests that there may well be differences in the labelling of asthma as indicated by other studies

Despite the variation in the number of participating GPs

between the countries, similar trends of high prevalence in the U.K. and Ireland and low in the

Mediterranean countries have been reported For antibacterial drugs, higher levels were found to be

prescribed for children in Belgium and Ireland and for adults in Scotland followed by Italy.

Antibacterial drug prescribing for asthma is considered to be irrational.

The incidence of asthma attacks diagnosed by GP’s in the UK and Ireland is about 5 times higher than it was 25 years ago.

A gap in patient/provider communications.

Braman S S Chest 2006;130:4S-12S©2006 by American College of Chest Physicians

Severe asthma is associated with disproportionately high costs in comparison with other degrees of asthma severity

Braman S S Chest 2006;130:4S-12S©2006 by American College of Chest Physicians

X people were diagnosed with asthma

X emergency admissions

X people had wheezing during past year

X Deaths

X Registered in primary care organisation

X received GP treatment

X Wheezing in past year

X Admissions

X Population

X Deaths

X Asthma diagnosis

Educate patients to develop a partnership in asthma management

Assess and monitor asthma severity with symptom reports and measures of lung function as much as possible

Avoid exposure to risk factors Establish medication plans for chronic management in

children and adults Establish individual plans for managing exacerbations Provide regular follow-up care http://www.ginasthma.org/

Improved communication of outcomes of specialist referrals

Increased involvement of specialist asthma nurses

More use of self-management plans Financial drivers for primary care, but

linked to quality of care

Poverty; inadequate resources Low public health priority Poor health-care infrastructure Difficulties in implementing guidelines

developed in wealthier countries Limited availability of and access to

medication

Lack of patient education Environmental factors Tobacco Pollution Occupational exposure Poor patient compliance

Despite considerable knowledge with regard to the pathologic basis of asthma, the ongoing increases in asthma prevalence and subsequent increases in morbidity and mortality cannot yet be explained.

In addition, the GINA goals of asthma management are not being achieved, with considerable under diagnosis and under appropriate or inappropriate treatment.

A significant proportion of patients are receiving only basic care and are not able to benefit from therapeutic advances.

For the majority of the population of the world, asthma is a low public heath priority.

The diversity of health-care systems worldwide and large variations in access to care require that asthma management guidelines to be tailored to local needs.

More cooperation is imperative between health-care officials and primary and secondary care providers in order to develop individualized asthma management programs that will work at a local level

Ireland to lead the way in asthma care (Posted: Fri 10/07/2009 by Joanne McCarthy)

Ireland is set to become one of the leading countries in the EU to tackle asthma in the community with the roll out of a programme that could see asthma-related hospitalisations halved and asthma deaths reduced by

90%.

http://www.asthmasociety.ie http://www.asthmacare.ie/ http://www.irishhealth.com/clin/asthma/index.html http://www.asthma-uk.co.uk/ http://www.greenparty.ie/en/policies/asthma_and_allergies/

profile_of_allergies_and_asthma_in_ireland http://www.who.int/respiratory/asthma/en/

1. Asher MI MS, Bjorksten B, Lai CKW, Strachan DP, Weiland SK, Williams H, and the ISAAC Phase Three Study Group Worldwide time trends in the prevalence of symptoms of asthma, allergic rhino conjunctivitis, and eczema in childhood: ISAAC Phase One and Three repeat multicountry cross-sectional surveys. Lancet. 2006;368:733-43.

2. Manning PJ Goodman P O'Sullivan A CL. Rising prevalence of asthma but declining wheeze in teenagers (1995-2003): ISAAC protocol. Irish Medical Journal. 2007;100(10):614-5.

3. Kelly I. Epidemiology of Asthma in Children and the use of Best Practice Guidelines in Primary care in the management of Children with Asthma in the counties of Laois, Offaly, Westmeath and Longford. Dublin: Royal College of Physicians of Ireland; 2008.