In 1991 and 1997, the National Heart, Lung, and Blood Institute's National Asthma Education and Prevention Program (NAEPP) issued guidelines for the diagnosis and management of asthma. An update on selected issues covered in the guidelines was published in 2002. The NAEPP guidelines have improved the standard and consistency of asthma care and have encouraged research into approaches and treatments leading to continuous advancements in the ability to help patients with asthma.
Although the guidelines have stimulated these advances, their application in clinical practice can be challenging. In particular, the recommendation of severity-based stratification of patients as a means of guiding treatment decisions can be problematic when followed without an appreciation of the challenges inherent in this approach. This issue of Advanced Studies in Medicine, which includes a review article, a case study, and a clinician interview, examines the challenges and practical implications of severity-based classification of patients with asthma.
In the NAEPP guidelines, intervention is tailored to patients' asthma severity, which is classified on the basis of lung function tests, symptoms, and functional ability as being mild intermittent, mild persistent, moderate persistent, or severe persistent. In their review, "Challenges in Assessing Asthma Severity in Clinical Practice," Drs Joseph Spahn and William J. Calhoun emphasize that these severity categories, with their corresponding treatment recommendations, are intended to be general guiding principles for therapeutic decision-making and that they need to be interpreted and applied with flexibility. This flexibility is necessary because of the difficulty in accurate determination of asthma severity in clinical practice. Drs Spahn and Calhoun discuss several factors that may impede accurate determination of asthma severity:
- Severity classification varies according to how it is assessed
- Asthma is a variable disease
- Patients underreport asthma symptoms
- Asthma control and asthma severity are not synonymous
- Mild asthma and/or normal spirometry do not necessarily translate into the absence of a need for careful monitoring or therapeutic intervention. Patients with mild asthma and/or normal spirometry can be sicker than pulmonary function tests reflect and can benefit from interventions typically reserved for patients in higher severity strata.
In the case study accompanying the review, Dr Spahn describes a case that illustrates how the above factors can complicate asthma assessment in clinical practice. The case illustrates that, while assessing asthma severity in the clinic can be difficult, careful attention to the patient and consideration of a range of measures can help in formulating an accurate assessment of asthma severity. To gain an additional perspective on the practical implications of severity-based stratification of patients with asthma, the Senior Contributing Editor for Advanced Studies in Medicine interviewed Dr Calhoun; excerpts of the interview are published in this issue. Aside from offering insight on assessing asthma severity in clinical practice, Dr Calhoun discusses his views on treatment approaches and recent developments in asthma.
Accurate assessment of asthma severity is critical in optimizing patient care. As Drs Spahn and Calhoun point out, misappraisal of patients' clinical status leads to inappropriate intervention, in which medication is either overprescribed or is underprescribed with a resulting deterioration of asthma control. Healthcare providers can improve their ability to gauge asthma severity in clinical practice by judiciously interpreting and applying the NAEPP guidelines while remaining vigilant about their limitations.
*Associate Professor of Medicine and Clinical Director, Division of Allergy and Clinical Immunology, Johns Hopkins University School of Medicine, and Medical Director, Asthma and Allergy Diseases, Johns Hopkins Asthma and Allergy Center, Baltimore, Maryland.