Controlled asthma imposes far less of an economic burden than non-controlled asthma. Strategies towards improving access and adherence to evidence-based therapies can therefore be effective in reducing the economic burden of asthma in both developed and developing countries.
ECONOMIC BURDEN OF ASTHMA
It is difficult to quantify the global economic burden of asthma, but estimates for separate countries and regions are tremendously high. The indirect costs of asthma, especially its negative impact on productivity, is at least as large as its direct costs. Attempts to reduce the economic burden of asthma should move towards better management of asthma. Improving access to care and adherence to evidence-based treatment can reduce the economic burden of asthma, even in locations where prevalence is rising.
Challenges in estimating the global economic burden of asthma
Diseases can cause economic loss in a number of ways. They can impose direct costs through consumption of resources (e.g., hospitalisations, physician visits, and medications), as well as indirect costs through loss of productivity. Globally, as a major non-communicable disease, asthma creates a tremendous economic burden, although the exact quantification of this burden is challenging. What is clear is that the economic burden of asthma is high, adding to the need for it to be recognised as a public health priority.
Attaching numbers to the economic burden of asthma is fraught with several challenges. One challenge is how to attribute resources to asthma. For example, it is difficult to tease out the contribution of asthma to depression in a patient with both conditions, or to attribute how many days of sick leave are due to asthma. Even estimating the prevalence of asthma, a key factor in estimating the burden at the regional and national level, is difficult, as seen in The Burden of Asthma/Global Burden, given the inconsistencies in definition, as well as under-diagnosis and over-diagnosis of asthma in different subgroups of individuals.
What we know about the global burden of asthma
Most studies on the burden of asthma are from developed countries, where national surveys of diseases and large, administrative databases, can be interrogated to provide a broad picture of the burden. The one systematic review (2009) illustrates the variation within countries and the relative lack of information from low-and middle-income countries. A recent study in the United States of America estimated that the total cost of asthma to society was $56 billion in 2007, or $3,259 per person per year (in 2009 US dollars). A further European study in 2011 has estimated the total cost of asthma in that year to be €19.3 billion among Europeans aged from 15 to 64 years (in 2011 Euros). In a separate study in the Asia-Pacific region, the sum of direct and indirect costs of asthma per person per year ranged from $184 in Vietnam to $1,189 in Hong Kong (in 2000 US dollars). Furthermore, there is a significant variation in cost estimates even among the studies from the same country. For example, US-based estimates of the cost of asthma per person vary up to five-fold. Despite the heterogeneous settings and different numbers, many studies have pointed towards the fact that the indirect cost of asthma is at least as large as its direct costs. This is not a surprising finding: disability from asthma affects individuals who are often at the most productive phase of their working lives, and parents of dependent children with asthma are also often in the workforce. Research also suggests that the contribution of “presenteeism” (individual loss of function when at work) is larger than absenteeism (inability to come to work) in patients with asthma. A recent Canadian study has shown that, compared with controlled asthma, uncontrolled asthma results in a $184 (in 2012 Canadian dollars) loss of productivity during a week for such a person, 90% of which is attributable to presenteeism.
The preventable burden of asthma: the importance of clinical control
Currently, asthma cannot be cured, and there are limited evidence-based options to prevent its development. The emphasis of asthma management is therefore focused on achieving clinical control with an added priority of preventing the future risk of exacerbations. Strategies which result in well-controlled asthma are associated with a significant reduction in economic burden compared to uncontrolled disease, as shown by programmes implemented in Salvador (Brazil) and Finland (for more examples see Management of Asthma/Asthma Management Strategies). Despite the wide availability of effective medications for several decades, asthma remains uncontrolled in a substantial proportion of the population. Thus, the incremental economic burden of uncontrolled asthma is of particular relevance to decision makers as it represents the aspect of the burden that is preventable.
Low adherence as a major cause of preventable burden
Research in diverse jurisdictions, including both developed and developing countries, has consistently shown that adherence to controller medications is poor. The evidence linking adherence to controller medications with better asthma outcomes is strong, making adherence a modifiable factor and a potential target for reducing the economic burden of asthma.
Improving access to care and adherence to evidence-based medication
Given the proven benefit of existing essential asthma medicines for most asthma patients, improving access and adherence to such treatments should be a major global priority (see Management of Asthma/Asthma Management in Low-Income Countries). In developing countries, additional barriers to delivering effective management may include poverty, poor education, and poor infrastructure, indicating that a more comprehensive approach is required, including political commitment to better asthma care (see Management of Asthma/Asthma Management in Low-Income Countries). In both developing and developed countries, improving adherence to controller treatment requires education of both care providers and patients about its long-term benefits. Developing interventions such as shared care models for asthma management, or the use of communication technologies to facilitate interaction between patients and care providers, can be beneficial. The role of health literacy and the socio-cultural context in which the patients find themselves are also important.
A small fraction (less than 10%) of patients with asthma which is difficult to control (refractory asthma) do not respond to conventional controller therapies and depend on treatments that are currently very expensive and only accessible in certain parts of the world. Reducing the cost of these treatments and making them accessible across the world will help reduce the burden due to refractory asthma. This requires the coordinated efforts of industry, government, non-governmental organisations (NGOs), and international organisations such as the World Health Organization (WHO).
Most countries have not yet estimated the costs of asthma. Where it has been estimated, the economic burden of asthma is great because of direct healthcare costs, and indirect costs, as a result of loss of productivity due to people being absent from work, or working less effectively while at work. The impact of these indirect costs would be diminished by improving asthma control, through improving access to good management including medicines.
Governments should measure and monitor the economic costs of asthma in their countries, including health care costs and productivity losses.