Predicting episodes of poor asthma control in treated patients with asthma.
BACKGROUND
Asthma exacerbations are dangerous, expensive, and difficult to anticipate.


OBJECTIVE
To characterize patients with asthma who had asthma episodes and exacerbations during 4 weeks of observation.


METHODS
A total of 2032 volunteers with asthma (age, 3-64 years; 62% female subjects) were studied over two 2-week intervals after flu vaccine and placebo. Baseline data, including several asthma questionnaires, were analyzed for prediction of subsequent asthma events as recorded on diaries detailing peak flow, medication use, and health care use.


RESULTS
During 28 days of diary collection, 43.2% of participants had at least 1 episode of poor asthma control. Most episodes were characterized by increased use of rescue medications or reductions in peak flow, but nearly 15% of participants had exacerbations characterized by use of systemic corticosteroids, unscheduled health care visits, or both. Episode frequency was highest in children <10 years of age. Additional risk factors were smoking, African American ethnicity, low lung function, and past history of severe asthma. The best predictors were symptom questionnaires, and a simple questionnaire concerning the preceding 2 weeks worked as well as more complex questionnaires or those reflecting longer periods. In regression analyses, questionnaire results, smoking, lung function, ethnicity, and asthma history all were associated with asthma episodes in people older than 10 years, whereas only asthma history was predictive in those <10 years.


CONCLUSIONS
Symptom questionnaires are predictive of subsequent asthma episodes in people older than age 10 years, but not in younger people.


CONCLUSIONS
Simple assessments may be helpful in identifying patients most at risk for future asthma episodes.
McCoy
Karen
K
Ohio State University, USA.
Shade
David M
DM
Irvin
Charles G
CG
Mastronarde
John G
JG
Hanania
Nicola A
NA
Castro
Mario
M
Anthonisen
N R
NR
D000293:Adolescent; D000328:Adult; D001741:Black or African American; D000367:Age Factors; D001249:Asthma / Q000175:diagnosis / Q000208:ethnology / Q000209:etiology* / Q000517:prevention & control*; D002648:Child; D002675:Child, Preschool; D004334:Drug Administration Schedule; D005260:Female; D006306:Health Surveys; D006801:Humans; D007252:Influenza Vaccines / Q000008:administration & dosage / Q000009:adverse effects*; D007251:Influenza, Human / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D055502:Secondary Prevention; D012907:Smoking; D011795:Surveys and Questionnaires; D014481:United States / Q000453:epidemiology; D014611:Vaccination
D007252:Influenza Vaccines