Pulmonary Disease: Asthma

Asthma and Law Enforcement Fitness-for-Duty

Asthma has been classified in various manners over the past 70 years with the current predominant clinically used classification based on a pathophysiologic concept of asthma as a disease primarily of airway inflammation dating from the 1960s. More recent research is leading to appreciation of a heterogeneous group of phenotypes with potential genetic implications. This evolving understanding is anticipated to improve individualization of treatment and lead to improvement in the number of patients able to achieve near complete control.

The 2007 National Asthma Education and Prevention Program’s Expert Panel Report 3, Guidelines for the Diagnosis and Management of Asthma (EPR-3), and the Global Initiative for Asthma (GINA) 2018 Global Strategy for Asthma Management and Prevention report, promulgate classification schemes based on severity and degree of control, defining asthma broadly as an inflammatory airway disorder with variable and recurring symptoms. Though somewhat older (2007), the EPR-3 model of stratification lends itself better to the purposes of this document’s focus on assessment of whether the status of a person’s asthma represents a degree of impairment or risk of impairment that might adversely affect their ability to safely and effectively perform essential LEO job tasks.

There are some differences between the EPR-3 document and the GINA report. EPR-3 primarily refers to asthma as a disorder of chronic airway inflammation with various manifestations, such as intermittent, persistent, exercise-associated, and aspirin-sensitive. Advances in knowledge of the pathophysiology in various sub-populations have led GINA to modify their definition to “a heterogeneous disease, usually characterized by chronic airway inflammation. It is defined by the history of respiratory symptoms such as wheeze, shortness of breath, chest tightness and cough that vary over time and in intensity, together with variable expiratory airflow limitation.” The variation referred to reflects the variable responses to inhaled steroid medications, variable airway hyper-responsiveness patterns and variation in cell types and quantities found in sputum in different patients. These differences form the basis for evolving discussions of multiple asthma phenotypes.

The remainder of this discussion is primarily based on the EPR-3 since it offers a classification system specifically targeting control in adults that can serve as a framework for the task of decision-making regarding ability to safely and effectively perform essential LEO job functions. Thus, citations will not be made for individual statements of fact unless from other sources, or if they represent points on which EPR-3 and GINA 2018 differ.

Three aspects of the clinical situation have been proposed by EPR-3 for assessing asthma:

• Severity, the intrinsic intensity of the disease – Recommended to be assessed on initial presentation or when a person has not been using any longer-term control medications, such as inhaled corticosteroids, for at least several months;
• Control, the degree to which manifestations of asthma are minimized in persons actively being treated, particularly, with inhaled corticosteroids;
• Responsiveness, the ease with which therapy achieves control.

Both Severity and Control are defined in two domains: Impairment and Risk.

Impairment degree is assessed through a combination of patient recall over the most recent 2 weeks, to a maximum of 4 weeks, of four aspects of effect on the person’s life (daytime symptom frequency, nighttime awakenings, use of SABA for symptom control, interference with normal activity) and spirometric (or Peak Expiratory Flow [PEF]) evaluation of lung function. EPR-3 cites several validated questionnaires for assessment of impairment. These cover some of the same issues of frequency and severity of symptoms, use of rescue inhalers and effect on lifestyle.

Table 1. Validated Questionnaires

Risk addresses the chance of future exacerbations or adverse reactions from medications and is classified according to:

• how many times over the prior year the person had been prescribed oral systemic corticosteroids to assist with resolving an episode of asthma exacerbation;
• the severity of an episode; and
• the interval between episodes.

Severity, proposed as an assessment to be performed before any treatment is started or when a person has not been using anti-inflammatory medications for several months, is classified into two categories: intermittent or persistent with persistent being subdivided into mild, moderate and severe (see Table 1).

Intermittent asthma is characterized as 2 or fewer days per week with any symptoms, no nighttime awakening, two or fewer uses of short-acting beta3-agonist (SABA) for symptom control per week other than with upper respiratory illness-associated exacerbations, no interference with normal activities and no more than one exacerbation having been treated with oral steroids in the prior year.

Persistent asthma is defined as more than 2 exacerbations in a year that led to treatment with oral systemic steroids. Persistent asthma is further characterized as mild, moderate, or severe based on frequency and intensity of exacerbations and on activity impairment. No firm data exist to support these classifications.

Table 2: Asthma Severity Classification for Youths ≥12 Years Old and Adults

*FEV1, forced expiratory volume in 1 second; FVC, forced vital capacity

NOTE: Per EPR-3, inadequate data existed at the time of the report to directly correlate frequency of exacerbations with severity, though it was generally felt that more frequent and intense exacerbations implied more severe disease severity. It was concluded that persons with ≥2 exacerbations requiring oral steroids in the prior year should be categorized as having persistent asthma even if the impairment level was not consistent with persistent disease.

Control has been proposed as the characteristic by which to assess the status of persons under established treatment, with inhaled corticosteroids designated as the foundation.

Table 3: Asthma Control Classification for Youths ≥12 Years Old and Adults (adapted from EPR-3)

*See above for discussion of validated questionnaires
†Comments in italics relate to specific focus of this document, not from EPR-3.

EPR-3 recommends that persons with asthma be assigned to the most severe category in which any of the features defining a category occurs. ERP-3 states that persons with 2 or more exacerbations in the past year who otherwise would be classified as well-controlled may be considered as having not-well-controlled asthma for purposes of treatment decisions.

It is important to recognize that asthma is not a static disorder. A person’s status in terms of severity or control can change in either direction. Additionally, persons in any category, including intermittent asthma, despite appearing well-controlled, can have severe acute attacks.

The exacerbation measure used by EPR-3 is the risk of an exacerbation requiring hospitalization or use of oral steroids. The EPR-3 and supporting literature do not address risk of exacerbations that may have limited a person’s ability to participate in activities.

The effect of asthma exacerbations on a person’s functional capabilities is highly variable. No medical literature has been identified that directly assesses functional capacity of persons with active bronchospasm.

At least one study has demonstrated that it is possible to achieve total control in nearly all adult patients with asthma, defining total control as an 8 week period with no symptoms or SABA use in 7 of the 8 weeks and daily morning peak expiratory flow ≥80% predicted. Additionally, with improved appreciation of the genomic and phenomic factors involved in the current diagnostic term of “asthma,” improved targeted treatments are anticipated.

Other Reactive Airway Disease Manifestations
Advancing understanding of the pathophysiology of reactive airway disorders has led to increasing appreciation of various different manifestations that respond differently to treatment and also have varying clinical courses. A full discussion of various phenotypes is both beyond the scope of this document and not particularly helpful at this point in evolution of understanding for the purposes of assessing subjects for impairment or risk of sudden impairment. However, this evolving understanding does improve the clinician’s appreciation that some persons may not be able to achieve control of their asthma despite strict adherence to a medical regimen considered optimal by today’s standards. These issues have, as of late 2016, been studied essentially only in the population of persons classified as having severe asthma.

Exercise-induced Asthma
Exercise-induced asthma refers to bronchospasm that occurs after a person has participated in exercise, more commonly in cool to cold, dry air. It is defined by at least a 10% decrease in, preferably, FEV1 as opposed to peak expiratory flow, using the lowest FEV1 value recorded within 30 minutes after exercise.13

Persons experiencing this phenomenon may have no other symptoms or evidence of asthma, particularly the inflammatory components. Persons with true exercise-induced asthma, as defined above, rarely have difficulty performing high-level physical activity.

Much more common is the phenomenon of persons experiencing wheezing and limitation during exercise. This situation is deemed by pulmonologists to more likely represent poorly controlled underlying asthma with inflamed airways that are primed to experience bronchospasm when irritated by the drying effect of increased bronchial air flow associated with exercising. Thus, the exercise difficulty in these patients may well be relieved by altering the patient’s baseline medication use.

EPR-3 concluded that, since exercise-induced bronchospasm (EIB) is often a marker for inadequate asthma management and that it responds well to anti-inflammatory treatment, persons with this condition should be monitored closely for any symptoms of asthma or decrease in peak expiratory flow when not exercising, thus suggesting a need to reclassify to a more persistent asthma status.