title: [Prevalence of asthma and determination of symptoms as risk indicators].
abstract: BACKGROUND
  Asthma is a chronic inflammatory airway disease whose prevalence has increased, especially in developed countries; the results of studies of asthma prevalence vary in different populations and even within the same country; in Mexico we observed fluctuations in prevalence of asthma from 7% to 33%.
  
  
  OBJECTIVE
  To determine the prevalence of asthma and severity of symptoms as risk indicators in school population in cities in various states of Mexico.
  
  
  METHODS
  A descriptive study of detection of asthma prevalence and analytical-comparative observational study of determination of symptoms of asthma. The surveys were applied to preschool, elementary, middle and high school population, in the cities of Puebla, Puebla; Tulancingo, Hidalgo; Tlaxcala, Tlaxcala, and Cancún, Quintana Roo; new validated questionnaire was used as instrument: Asthma Diagnostic Questionnaire for Epidemiologic Studies, consisting of eight questions with summation value for diagnosis.
  
  
  RESULTS
  8,754 surveys showed a 14% prevalence in Puebla, 17% in Tulancingo, 7% in Tlaxcala, and 14% in Cancún; average in four cities surveyed was 13%; the strength of association with asthma symptoms in descending order with significant odds ratio were: recurrent wheezing, breathlessness, chest tightness, recurrent cough, cough cold, recurrent cold symptoms, predominantly nocturnal cough, cough that increases with exercise.
  
  
  CONCLUSIONS
  The average prevalence of asthma in the surveyed cities was 13% and the main symptoms indicators of risk of asthma in school children were: recurrent wheezing, breathlessness, chest tightness and recurrent cough.
authors.affiliation: Colegio Mexicano de Inmunología Clínica y Alergia A. C., Distrito Federal, México. manele05@yahoo.com.mx.
authors.forename: Eleazar
authors.initials: E
authors.lastname: Mancilla-Hernández
authors.forename: Miguel Alejandro
authors.initials: MA
authors.lastname: Medina-Ávalos
authors.forename: Raúl Humberto
authors.initials: RH
authors.lastname: Barnica-Alvarado
authors.forename: Diego
authors.initials: D
authors.lastname: Soto-Candia
authors.forename: Rosario
authors.initials: R
authors.lastname: Guerrero-Venegas
authors.forename: Yahvéh
authors.initials: Y
authors.lastname: Zecua-Nájera
keywords: asthma; prevalence; risk indicators; symptoms