title: Risk of Obstructive Sleep Apnea in Adult Patients with Asthma: A Population-Based Cohort Study in Taiwan.
abstract: BACKGROUND
  There are several publications reported that obstructive sleep apnea (OSA) was associated with asthma. However, large-scaled, population-based cohort study has been limited. We aimed to examine the risk of OSA among adult patients with asthma in an Asian population.
  
  
  METHODS
  We conducted a retrospective cohort study using data from the National Health Insurance (NHI) of Taiwan. The asthma cohort included 38,840 newly diagnosed patients between 2000 and 2010. The date of diagnosis was defined as the index date. Each patient was randomly matched with four people without asthma according to gender, age, and the index year as the comparison cohort. The occurrence of OSA was followed up until the end of 2011. The risk of OSA was estimated using the Cox proportional hazard model after adjusting for gender, age, and comorbidities.
  
  
  RESULTS
  The overall incidence of OSA was 2.51-fold greater in the asthma cohort than in the comparison cohort (12.1 versus 4.84 per 1000 person-years). Compared to non-asthma subjects, the adjusted hazard ratio (aHR) of OSA increased to 1.78 for asthma patients with one or less annual emergency room (ER) visit, and 23.8 for those who visited ER more than once per year. In addition, aHR in patients with inhaled steroid treatment compared to those without steroid treatment was 1.33 (95% CI = 1.01-1.76).
  
  
  CONCLUSIONS
  Patients with asthma have a significantly higher risk of developing OSA than the general population. The results suggest that the risk of OSA is proportional to asthma control and patients with inhaled steroid treatment have a higher risk for OSA than those without steroid treatment.
authors.affiliation: Graduate Institute of Clinical Medicine Science, College of Medicine, China Medical University, Taichung, Taiwan; Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan.
authors.forename: Te-Chun
authors.initials: TC
authors.lastname: Shen
authors.affiliation: Management Office for Health Data, China Medical University Hospital, Taichung, Taiwan.
authors.forename: Cheng-Li
authors.initials: CL
authors.lastname: Lin
authors.affiliation: Division of Nephrology, Department of Pediatrics, China Medical University Hospital, Taichung, Taiwan.
authors.forename: Chang-Ching
authors.initials: CC
authors.lastname: Wei
authors.affiliation: Graduate Institute of Clinical Medicine Science, College of Medicine, China Medical University, Taichung, Taiwan; Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan.
authors.forename: Chia-Hung
authors.initials: CH
authors.lastname: Chen
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan.
authors.forename: Chih-Yen
authors.initials: CY
authors.lastname: Tu
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan.
authors.forename: Te-Chun
authors.initials: TC
authors.lastname: Hsia
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan.
authors.forename: Chuen-Ming
authors.initials: CM
authors.lastname: Shih
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan.
authors.forename: Wu-Huei
authors.initials: WH
authors.lastname: Hsu
authors.affiliation: Graduate Institute of Clinical Medicine Science, College of Medicine, China Medical University, Taichung, Taiwan; Management Office for Health Data, China Medical University Hospital, Taichung, Taiwan.
authors.forename: Fung-Chang
authors.initials: FC
authors.lastname: Sung
authors.affiliation: Graduate Institute of Clinical Medicine Science, College of Medicine, China Medical University, Taichung, Taiwan; Department of Nuclear Medicine and PET Center, China Medical University Hospital, Taichung, Taiwan.
authors.forename: Chia-Hung
authors.initials: CH
authors.lastname: Kao
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001249:Asthma / Q000175:diagnosis* / Q000453:epidemiology; D015331:Cohort Studies; D015897:Comorbidity; D004632:Emergency Medical Services / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors; D012737:Sex Factors; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis* / Q000453:epidemiology; D013624:Taiwan / Q000453:epidemiology