PURPOSE OF THE STUDY: To evaluate the prevalence of comorbid allergic rhinitis in children with persistent asthma in school-based asthma programs, and to determine whether these children have increased asthma symptoms and morbidity. STUDY POPULATION: There were 225 videos screened, with 86 meeting the inclusion criteria for further evaluation. STUDY POPULATION: The study population included 1029 children between the ages of 3 to 10 years with persistent or poorly controlled, physician-diagnosed asthma. The children were all included in 3 school-based asthma clinical trials in the Rochester City School District. METHODS: The prevalence of allergic rhinitis was ascertained from baseline survey data. The primary outcome was the mean number of days without asthma symptoms over 2 weeks, including daytime symptoms, nighttime symptoms, and rescue medication use. The association between allergic rhinitis and asthma symptom-free days was examined while adjusting for multiple child and caregiver characteristics. RESULTS: Among the 1029 children with persistent asthma, 63% had allergic rhinitis, with the majority experiencing symptoms around dust mites and pollen. Children with persistent asthma and allergic rhinitis had significantly more days with asthma symptoms, more daytime symptoms, and more rescue medication use when compared with children without allergic rhinitis. Among the 646 children with allergic rhinitis, 44% reported using allergy medications, with only 28% using intranasal corticosteroids. CONCLUSIONS: This study identified that the majority of children with persistent asthma in school-based asthma programs have allergic rhinitis, and the presence of allergic rhinitis is associated with increased asthma morbidity. [ABSTRACT FROM AUTHOR]