title: Increased risk of concurrent asthma among patients with gastroesophageal reflux disease: a nationwide population-based study.
abstract: OBJECTIVE
  The possibility of a relationship between gastroesophageal reflux disease (GERD) and asthma has been controversial. Using a nationwide population-based data set, this study aims to investigate the prevalence and risk of concurrent asthma among GERD patients, compared with patients without GERD in Taiwan.
  
  
  METHODS
  This study used the National Health Insurance Research Database. A total of 61 941 patients with GERD and 61 941 randomly selected patients without GERD were included from the year 2006. Conditional logistic regression analyses were used to explore the risk of concurrent asthma for patients with and without GERD. Furthermore, the analyses performed were stratified by sex and age (18-44, 45-64, 65-74 and > 74 years) to evaluate the association between GERD and concurrent asthma.
  
  
  RESULTS
  Of the 123 882 sampled patients, 3% (3681 patients) were diagnosed with asthma in 2006, consisting of 3.9% of the GERD patients (2427 from the study group) and 2% of the patients without GERD (1254 from the comparison group). Conditional logistic regression analysis showed that the odds of concurrent asthma for patients with GERD were 1.97 times greater [95% confidence interval (CI) =1.84-2.12, P < 0.001] than the odds of asthma for patients without GERD. When stratifying by age groups, the odds ratios for GERD with concurrent asthma were 2.61 (95% CI=2.24-3.03, P<0.001) for patients 18-44 years of age, 2.00 for patients 45-64 years of age (95% CI=1.79-2.23, P<0.001), 1.58 for those aged 65-74 (95% CI=1.36-1.83, P<0.001) and 1.80 for those aged 75 years or more (95% CI=1.52-2.12, P<0.001).
  
  
  CONCLUSIONS
  Patients with GERD had a significantly higher risk of concurrent asthma compared with patients without GERD.
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Taipei Medical University, Taipei, Taiwan.
authors.forename: Ming-Chieh
authors.initials: MC
authors.lastname: Tsai
authors.forename: Hsiu-Li
authors.initials: HL
authors.lastname: Lin
authors.forename: Ching-Chun
authors.initials: CC
authors.lastname: Lin
authors.forename: Hsiu-Chen
authors.initials: HC
authors.lastname: Lin
authors.forename: Yi-Hua
authors.initials: YH
authors.lastname: Chen
authors.forename: Stefani
authors.initials: S
authors.lastname: Pfeiffer
authors.forename: Herng-Ching
authors.initials: HC
authors.lastname: Lin
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001249:Asthma / Q000453:epidemiology*; D016208:Databases, Factual; D005260:Female; D005764:Gastroesophageal Reflux / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009313:National Health Programs / Q000706:statistics & numerical data; D015995:Prevalence; D012307:Risk Factors; D013624:Taiwan / Q000453:epidemiology; D055815:Young Adult