global strategy for asthma management and prevention

GINA_WR_2006.qxp:GINA_WR_2006.qxp 7/20/07 4:11 PM Page 3THE BURDEN OF ASTHMAPrevalence, Morbidity, and MortalityAsthma is a problem worldwide, with an estimated 300million affected individuals 2,3 . Despite hundreds of reportson the prevalence of asthma in widely differing populations,the lack of a precise and universally accepted definition ofasthma makes reliable comparison of reported prevalencefrom different parts of the world problematic. Nonetheless,based on the application of standardized methods tomeasure the prevalence of asthma and wheezing illness inchildren 3 and adults 4 , it appears that the global prevalenceof asthma ranges from 1% to 18% of the population indifferent countries (Figure 1-1) 2,3 . There is good evidencethat asthma prevalence has been increasing in somecountries 4-6 and has recently increased but now may havestabilized in others 7,8 . The World Health Organization hasestimated that 15 million disability-adjusted life years(DALYs) are lost annually due to asthma, representing1% of the total global disease burden 2 . Annual worldwidedeaths from asthma have been estimated at 250,000 andmortality does not appear to correlate well with prevalence(Figure 1-1) 2,3 . There are insufficient data to determine thelikely causes of the described variations in prevalencewithin and between populations.Figure 1-1. Asthma Prevalence and Mortality 2, 3Permission for use of this figure obtained from J. Bousquet.days lost from work are reported as substantial social andeconomic consequences of asthma in studies from theAsia-Pacific region, India, Latin America, the UnitedKingdom, and the United States 9-12 .The monetary costs of asthma, as estimated in a varietyof health care systems including those of the UnitedStates 13-15 and the United Kingdom 16 are substantial.In analyses of economic burden of asthma, attentionneeds to be paid to both direct medical costs (hospitaladmissions and cost of medications) and indirect, nonmedicalcosts (time lost from work, premature death) 17 .For example, asthma is a major cause of absence fromwork in many countries, including Australia, Sweden,the United Kingdom, and the United States 16,18-20 .Comparisons of the cost of asthma in different regionslead to a clear set of conclusions:• The costs of asthma depend on the individual patientʼslevel of control and the extent to which exacerbationsare avoided.• Emergency treatment is more expensive than plannedtreatment.• Non-medical economic costs of asthma are substantial.• Guideline-determined asthma care can be cost effective.• Families can suffer from the financial burden of treatingasthma.Although from the perspective of both the patient andsociety the cost to control asthma seems high, the cost ofnot treating asthma correctly is even higher. Propertreatment of the disease poses a challenge for individuals,health care professionals, health care organizations, andgovernments. There is every reason to believe that thesubstantial global burden of asthma can be dramaticallyreduced through efforts by individuals, their health careproviders, health care organizations, and local andnational governments to improve asthma control.Detailed reference information about the burden of asthmacan be found in the report Global Burden of Asthma* .Further studies of the social and economic burden ofasthma and the cost effectiveness of treatment are neededin both developed and developing countries.Social and Economic BurdenSocial and economic factors are integral to understandingasthma and its care, whether viewed from the perspectiveof the individual sufferer, the health care professional, orentities that pay for health care. Absence from school and*(http://www.ginasthma.org/ReportItem.asp?l1=2&l2=2&intId=94).DEFINITION AND OVERVIEW 3