title: Respiratory tract infections and asthma control in children.
abstract: BACKGROUND
  Asthma control is considered the major goal of asthma management, while many determinants of control are difficult to modify. We studied the association between respiratory infection episodes (RTIs) of various types and asthma control.
  
  
  METHODS
  Cross-sectional data were used from children aged 4-18 years with physician-diagnosed asthma who participated in a web-based electronic portal for children with asthma, allergies or infections. Asthma control was measured using the Childhood Asthma Control Test (C-ACT) or the Asthma Control Test (ACT). Linear regression was used to analyse the association between categories of numbers of various types of RTIs sustained in the preceding 12 months (categorized) and asthma control, adjusted for potential confounders.
  
  
  RESULTS
  Asthma control was assessed in 654 children, and 68.5% were clinically well controlled (ACT ≥ 20). Higher total numbers of RTIs in the last 12 months were strongly associated with a lower level of asthma control (p(trend) < 0.001). Similarly strong statistically significant associations were found for subtypes of RTI: ≥4 vs. 0 otitis episodes: coefficient -1.7 (95% CI -3.3 to -0.2); ≥5 vs.0 colds: coefficient -2.3 (95% CI -3.0 to -1.6); ≥3 vs. 0 bronchitis episodes: coefficient -3.1 (95% CI -4.0 to -2.3), each with p(trend) < 0.05.
  
  
  CONCLUSIONS
  Higher numbers of reported respiratory tract infections are associated with lower level of asthma control. The different type of respiratory tract infections contribute equally to less controlled asthma.
authors.affiliation: Department of Paediatric Pulmonology and Allergology, University Medical Centre Utrecht, Lundlaan 6, 3508 AB Utrecht, The Netherlands. Electronic address: k.zomer-kooijker@umcutrecht.nl.
authors.forename: Kim
authors.initials: K
authors.lastname: Zomer-Kooijker
authors.affiliation: Julius Centre for Health Sciences and Primary Care, University Medical Centre Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands.
authors.forename: Cuno S P M
authors.initials: CS
authors.lastname: Uiterwaal
authors.affiliation: Department of Paediatric Pulmonology and Allergology, University Medical Centre Utrecht, Lundlaan 6, 3508 AB Utrecht, The Netherlands.
authors.forename: Kim J C
authors.initials: KJ
authors.lastname: Verschueren
authors.affiliation: Utrecht Institute for Pharmaceutical Sciences, Division of Pharmacoepidemiology & Clinical Pharmacology, David de Wied Building, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands.
authors.forename: Anke-Hilse
authors.initials: AH
authors.lastname: Maitland-vd Zee
authors.affiliation: St. Antonius Hospital, Department of Paediatrics, Postbus 2500, 3430 EM Nieuwegein, The Netherlands.
authors.forename: Walter A F
authors.initials: WA
authors.lastname: Balemans
authors.affiliation: Tergooi Hospital, Department of Paediatrics, Rijksstraatweg 1, 1261 AN Blaricum, The Netherlands.
authors.forename: Bart E
authors.initials: BE
authors.lastname: van Ewijk
authors.affiliation: Meander Medisch Centrum, Department of Paediatrics, Postbus 1502, 3800 BM Amersfoort, The Netherlands.
authors.forename: Maartje F
authors.initials: MF
authors.lastname: van Velzen
authors.affiliation: Department of Paediatric Pulmonology and Allergology, University Medical Centre Utrecht, Lundlaan 6, 3508 AB Utrecht, The Netherlands.
authors.forename: Cornelis K
authors.initials: CK
authors.lastname: van der Ent
mesh_terms: D000293:Adolescent; D001249:Asthma / Q000150:complications* / Q000188:drug therapy; D001991:Bronchitis / Q000150:complications*; D002648:Child; D002675:Child, Preschool; D003139:Common Cold / Q000150:complications*; D003430:Cross-Sectional Studies; D004485:Eczema / Q000150:complications; D005260:Female; D005512:Food Hypersensitivity / Q000150:complications; D006801:Humans; D008297:Male; D010031:Otitis / Q000150:complications*; D012220:Rhinitis / Q000150:complications; D012307:Risk Factors; D016896:Treatment Outcome
keywords: Asthma; Bronchitis; Children; Control; Otitis; Respiratory tract infections