No abstract

Objective The purpose of this study was to determine the relationship of poor asthma control to bronchodilator response (BDR) phenotypes in children with normal spirometry. Methods Asthmatic children were assessed for clinical indices of poorly controlled asthma. Pre and post bronchodilator spirometry were performed and the percent BDR determined. Multivariate logistic regression assessed the relationship of the clinical indices to BDR at ≥8%, ≥10% and ≥12% BDR thresholds. Results There were 510 controller naïve, and 169 on controller medication. In the controller naïve population the mean age (± 1SD) was 9.5 (3.4), 57.1% were male, 85.7% Hispanic. Demographics were similar in both populations. In the adjusted profile, significant clinical relationships were found particularly to positive BDR phenotypes ≥10% and ≥12% versus negative responses including younger age, (odds ratios (OR) 2.0, 2.5; P <.05), atopy (OR 1.9, 2.6;P< .01), nocturnal symptoms in females (OR 3.4, 3.8;P< .01); beta2 agonist use (OR 1.7, 2.8;P< .01); and exercise limitation (OR 2.2, 2.5;P< .01) only in the controller naïve population. Conclusions The BDR phenotype ≥10% is significantly related to poor asthma control providing a potentially useful objective tool in controller naïve children even when prebronchodilator spirometry is normal.

The NAEPP guidelines 2002, based on symptom-frequency criteria as assessed in this study, seem to offer a valid basis for classifying asthma severity in those >5 years of age but may underclassify younger children. Our data suggest that morbidity experienced in the prior year may provide a useful additional criterion for classifying asthma severity, particularly in those children < or =5 years of age.

Urban minority children have higher rates of asthma morbidity due to multiple factors. Many school-based programs have been funded to improve asthma management, especially for these "high-risk" inner-city children with asthma. Here we report the outcomes of the Children's Hospital of Orange County Breathmobile program, which is a school-based asthma program that combines the use of a mobile clinic and a pediatric asthma specialist. Baseline evaluations included a detailed history and physical, skin prick test to common allergens, spirometry measurements, and asthma severity classification based on the current National Asthma Education and Prevention Program guidelines. From April 2002 to September 2005, a total of 1321 children were evaluated for asthma. Analysis of the 1112 (84%) children diagnosed with asthma showed a population mean age of 7.8 years, 81% Latino ethnicity, and 73% with persistent disease. At baseline, only 24% of children with persistent asthma were on daily anti-inflammatory medications, which increased to 78% by the first follow-up visit. In the year prior to entry into the program, 64% had school absenteeism related to asthma (38% >10 days), 45% had emergency room (ER) visits (28% >1), and 19% had hospitalizations (9% >1). There was a significant reduction (p < .001) in the annual rates of ER visits, hospitalizations, and school absenteeism when comparing pre- and postentry into the program. These data suggest that a mobile asthma van clinic at the school site with an asthma specialist could be an effective model in reducing morbidity in the underserved child with asthma. Further studies are necessary to determine whether this model is applicable to other inner-city settings.