Change in asthma control over time: predictors and outcomes
Published Online October 16, 2013
Maintenance of asthma control over time is a clear goal of national asthma guidelines, but few studies have addressed the natural history of asthma control over time. In a recent article published in The Journal of Allergy and Clinical Immunology: In Practice, Schatz, et al describe the change in the impairment domain of asthma control over time in patients with persistent asthma and identify predictors and consequences of controlled and uncontrolled asthma over time.
Patients aged 18-56 with persistent asthma who completed baseline (November, 2007) and follow-up asthma surveys (April, July, October of 2008) were included in the study. The survey included the Asthma Control Test (ACT) as well as questions regarding other patient and asthma characteristics. Health care utilization (pharmacy and exacerbations) for 2008 was obtained from administrative data.
The baseline and first follow-up surveys were completed by 1,267 patients, and all four surveys were completed by 782 patients. Patients well-controlled at baseline were significantly more likely (p < 0.0001) to be well-controlled over the following year (76.2-80.4 %) than patients who were uncontrolled at baseline (33.5-36.9 %). Prior exacerbations, smoking, Black race, low income, and increased body mass index (BMI) increased the risk of uncontrolled asthma over time. Asthma was more likely to be well controlled in the summer compared to other time periods. Patients whose asthma control improved over the first several months of follow-up experienced significantly (p < 0.05) fewer exacerbations over the subsequent year than patients with initially uncontrolled asthma who did not improve.
The authors concluded that the degree of asthma control at one point in time is strongly related to the achievement or maintenance of control and to asthma exacerbations over time. Thus, patients with uncontrolled asthma should receive intensive management and follow-up in an attempt to achieve well-controlled asthma over time and prevent exacerbations.
The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.