title: Effects of time, sex, ethnic origin, and area of residence on prevalence of asthma in Israeli adolescents.
abstract: OBJECTIVE
  To study effects of time, sex, ethnic origin, and area of residence on prevalence of asthma in Israeli adolescents.
  
  
  METHODS
  Retrospective survey of asthma from computerised medical draft records of conscripts examined up to the end of 1989.
  
  
  METHODS
  Five regional centres in Israel.
  
  
  METHODS
  443 186 conscripts (262 836 males and 180 350 females) aged 17-18 who were born over a nine year period.
  
  
  METHODS
  Asthma determined by medical history, physical examination, and lung function tests at rest and after exercise.
  
  
  RESULTS
  Asthma was more prevalent in males than females (26.5/1000 v 21.4/1000, relative risk 1.25 (95% confidence interval 1.19 to 1.32)). Subjects were split into three groups according to year of birth, and prevalence of asthma increased over time from 18/1000 to 24/1000 to 36/1000 (risk of asthma 0.56 (0.54 to 0.59) for first birth group relative to last birth group and 0.69 (0.66 to 0.72) for second group relative to last group). Risk of asthma was also affected by ethnic origin (highest for Western origin and lowest for north African origin, relative risk 1.63 (1.56 to 1.71)) and area of residence (highest in the central coastal region--risk of 1.24 (1.19 to 1.30) relative to the north coastal region--and lowest in inland areas--risk of 0.67 (0.64 to 0.70) relative to north coastal region).
  
  
  CONCLUSIONS
  Prevalence of asthma in Israel is increasing and is higher in males, in people of Western origin, and in those living in the most industrialised coastal region.
authors.affiliation: Department of Internal Medicine B, Lady Davis Carmel Hospital, Haifa, Israel.
authors.forename: A
authors.initials: A
authors.lastname: Laor
authors.forename: L
authors.initials: L
authors.lastname: Cohen
authors.forename: Y L
authors.initials: YL
authors.lastname: Danon
mesh_terms: D000293:Adolescent; D001249:Asthma / Q000453:epidemiology* / Q000208:ethnology; D005260:Female; D006801:Humans; D007557:Israel / Q000453:epidemiology; D008297:Male; D008889:Military Personnel; D015995:Prevalence; D012111:Residence Characteristics; D012189:Retrospective Studies; D012307:Risk Factors; D012737:Sex Factors; D013997:Time Factors