Relationship of physician estimate of underlying asthma severity to asthma outcomes

Background: Implementation of national guidelines for the treatment of asthma requires physician estimates of patients' underlying asthma severity. Asthma severity is commonly assigned based on respiratory symptoms. Objective: To evaluate the relationship of guideline-based physician assessments to asthma control. Methods: Data were collected by survey as part of a cohort study of adults with asthma. Physicians estimated the underlying severity of their patients' asthma as mild, moderate, or severe. We evaluated the relationship of these estimates to (1) general health status, asthma symptoms, and patient-reported emergency department (ED) visits and hospitalizations in the previous year and (2) outcomes in the following year. Results: A total of 3,468 adults with asthma had physicians who completed assessments of their severity. Physician evaluation of severity was significantly associated with the patient's recent general health status, asthma symptom control, ED visits, and hospitalizations (P < .001 for all). Future outcomes, including hospitalizations and ED visits for asthma, increased with increasing severity rating (hospitalizations: 5% [mild] vs 11% [moderate] vs 19% [severe]; ED visits: 15% [mild] vs 22% [moderate] vs 32% [severe]; P < .001 for all). Conclusion: This study provides evidence of the validity of physician assessments of patients' underlying asthma severity using the strategy recommended by national guidelines.