Recent estimates suggest nearly 25 million Americans have asthma, and more than 3,000 people die each year from complications with the disease, according to the Centers for Disease Control and Prevention.
Given that treatment for asthma is readily available and undergoing constant updates and improvements, this mortality rate is difficult to accept. The persistent enigma remains with a sub group of people who have what’s known as severe asthma. This group is not only experiencing most of the deaths, but also comprises the majority of hospitalizations and therefore, the high cost of care for this condition.
There are newer techniques for identifying individuals with the risk that will likely make them part of this subgroup. New knowledge about characteristics of different asthmatics that groups them into phenotypes helps to isolate individuals with severe asthma risk. (Phenotype applies to individuals with common, genetic features that predict their interaction with certain environments.)
There are three organizations that have undertaken the task of addressing severe asthma. Here we’ll look into what function they have and how they’re working to prevent people from dying from it.
The big three
The National Education and Prevention Program (NAEPP) created the Expert Panel Report-3 in conjunction with the National Heart, Lung, and Blood Institute.
The NAEPP committee developed the classification of asthma into these categories: mild-intermittent, mild, moderate, and severe-persistent. This classification system is based on the number of acute exacerbations a person has per week, the number of awakenings they have from sleep due to shortness of breath per month, and also on the objective results from spirometry screenings and use of single breath peak flows.
Physicians then give therapeutic recommendations based on which classification a person falls under. This is a dynamic process since individuals often move between different levels of severity as they go through life.
When it comes to severe asthma, this committee added measures of identifying and controlling triggers. These include workplace irritants, for example, that can cause permanent airway changes in a person who is persistently exposed to them over time. In children, indoor environmental triggers include cigarette smoke from adults and dust mites in sheets and pillowcases.
The NAEPP guidelines also direct treatment and limiting comorbidities — conditions that commonly occur alongside asthma, like gastric acid reflux and sneezing and runny nose — which may be responsible for asthma exacerbations even after increasing medication doses. New updates also address “overlap syndromes,” which combine asthma with other conditions that prolong symptoms (severity) like smokers with chronic obstructive pulmonary disease (COPD) and obese people with obstructive sleep apnea.
The second organization is the Global Initiative for Asthma (GINA).
GINA was established in 1993 in collaboration with the National Heart, Lung, and Blood institute and the World Health Organization (WHO). This is a different government organization from the one that developed the NAEPP. GINA examines asthma from a global perspective. This is significant since there are differences in the management of asthma in different environments and cultures — especially in how accessible treatment is and how it is received. This group’s guidelines also stress the selection of phenotypes to individualize therapy and predict response.
GINA also stresses the importance of follow-up since patients with asthma frequently stop seeing their provider once their symptoms are under control. GINA also developed a clinical algorithm for distinguishing “uncontrolled asthma” and “severe refractory asthma,” which seem similar but actually have differences. The GINA report takes a more pragmatic approach. It also includes specific recommendations for when it’s appropriate to seek help from a specialist, which is important as there is a scarcity of specialists in the field.
The third organization that has addressed severe asthma is a joint effort between the American Thoracic Society and the European Thoracic Society.
They performed a literature review and assembled a committee to create a GRADE approach. The GRADE system is Grading of Recommendations, Assessment, Development, and Evaluation.
The quality of the evidence in the studies is based on confidence in the available “estimates of treatment outcomes.” Studies in the medical literature are categorized as high, moderate, low, and very low confidence in findings. GRADE levels of recommendations depend on the available evidence.
To summarize this first part of the severe asthma discussion, each of these organizations has developed a strategy of approach to severe asthma by addressing the following elements:
- Agreeing on the proper definition of severe persistent asthma and the distinction of a separate condition called uncontrolled asthma.
- Evaluating for other conditions that may mimic asthma and that therefore may need different treatment modalities (they sometimes occur concurrently with asthma).
- Assessing contributory factors and triggers that instigate the asthma exacerbations (attempt of environmental control).
- Identifying characteristics of asthma phenotypes to see who would benefit from additional measures such as allergic desensitization.
- Identifying the best time to use advanced treatment modalities, such as the use of biological agents or thermoplasty.