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and unpublished studies The effect of prior atopic illness, was largely explained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