title: Prevalence and clinical profile of difficult-to-control severe asthma in children: results from pneumology and allergy hospital units in Spain.
abstract: BACKGROUND
  Severe asthma is often poorly controlled and its prevalence in Spanish children is unknown. The aim was to determine the prevalence of difficult-to-control severe asthma in children, the agreement of asthma control between physicians and Spanish Guidelines for Asthma Management (GEMA), and the health-related quality of life (HRQoL) for children and parents.
  
  
  METHODS
  Observational, cross-sectional, two-phase, multicentre study. In the first phase, all children who attended pneumology and allergy units during a three-month period were classified according to physicians' criteria as patients with: asthma, severe asthma, or difficult-to-control severe asthma. Patients aged 6-14 years with severe asthma (difficult-to-control or controlled) were included in the second phase.
  
  
  RESULTS
  12,376 asthmatic children were screened in the first phase. According to physicians' criteria, 8.8% (95% CI 8.3-9.3%) had severe asthma. Of these, 24.2% (95% CI, 21.7-26.8%) had difficult-to-control severe asthma. 207 patients with severe asthma (mean age 10.8 ± 2.3 years; 61.4% male; mean of 5.5 ± 3.4 years since asthma diagnosis) were included in the second phase. Compared to the patients with controlled asthma, children with difficult-to-control asthma had a higher number of exacerbations, emergency room or unscheduled primary care visits in the previous year (p<0.0001, all) and poor HRQoL (p<0.0001, both children and caregivers). 33.3% of patients with controlled asthma according to physicians' criteria were poorly controlled according to GEMA.
  
  
  CONCLUSIONS
  Around one in four asthmatic children with severe disease had difficult-to-control asthma, although one third was underestimated by physicians. Children with difficult-to-control severe asthma had a poor HRQoL that also affected their parents.
authors.affiliation: Allergy and Clinical Immunology Department, Sant Joan de Déu Hospital, Esplugues de Llobregat, 08950 Barcelona, Spain. Electronic address: aplaza@hsjdbcn.org.
authors.forename: A M
authors.initials: AM
authors.lastname: Plaza-Martín
authors.affiliation: Pneumology Department, Hospital Clinic of Barcelona, 08036 Barcelona, Spain.
authors.forename: M C
authors.initials: MC
authors.lastname: Vennera
authors.affiliation: Medical Department, Novartis Farmacéutica, Gran Via de les Corts Catalanes, 764, 08013 Barcelona, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Galera
authors.affiliation: Medical Department, Novartis Farmacéutica, Gran Via de les Corts Catalanes, 764, 08013 Barcelona, Spain.
authors.forename: L
authors.initials: L
authors.lastname: Herráez
mesh_terms: D000293:Adolescent; D000486:Allergy and Immunology; D018927:Anti-Asthmatic Agents / Q000627:therapeutic use; D001249:Asthma / Q000188:drug therapy* / Q000453:epidemiology*; D002648:Child; D003430:Cross-Sectional Studies; D018450:Disease Progression; D005260:Female; D006757:Hospital Units / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D010290:Parents; D017410:Practice Guidelines as Topic; D015995:Prevalence; D015272:Pulmonary Medicine; D011788:Quality of Life; D013030:Spain / Q000453:epidemiology
chemical_list: D018927:Anti-Asthmatic Agents
keywords: Childhood; Difficult-to-control asthma; GEMA; Health-related quality of life; Severe asthma