title: Effect of Systemic Lupus Erythematosus on the Risk of Incident Respiratory Failure: A National Cohort Study.
abstract: OBJECTIVE
  We conducted a nationwide cohort study to investigate the relationship between systemic lupus erythematosus (SLE) and the risk of incident respiratory failure.
  
  
  METHODS
  From the National Health Insurance Research Database, we identified 11 533 patients newly diagnosed with SLE and 46 132 controls without SLE who were randomly selected through frequency-matching according to age, sex, and index year. Both cohorts were followed until the end of 2011 to measure the incidence of incident respiratory failure, which was compared between the 2 cohorts through a Cox proportional hazards regression analysis.
  
  
  RESULTS
  The adjusted hazard ratio (aHR) of incident respiratory failure was 5.80 (95% confidence interval [CI] = 5.15-6.52) for the SLE cohort after we adjusted for sex, age, and comorbidities. Both men (aHR = 3.44, 95% CI = 2.67-4.43) and women (aHR = 6.79, 95% CI = 5.93-7.77) had a significantly higher rate of incident respiratory failure in the SLE cohort than in the non-SLE cohort. Both men and women aged <35 years (aHR = 31.2, 95% CI = 21.6-45.2), 35-65 years; (aHR = 6.19, 95% CI = 5.09-7.54) and ≥65 years (aHR = 2.35, 95% CI = 1.92-2.87) had a higher risk of incident respiratory failure in the SLE cohort. Moreover, the risk of incident respiratory failure was higher in the SLE cohort than the non-SLE cohort, for subjects with (aHR = 2.65, 95% CI = 2.22-3.15) or without (aHR = 9.08, 95% CI = 7.72-10.7) pre-existing comorbidities. In the SLE cohort, subjects with >24 outpatient visits and hospitalizations per year had a higher incident respiratory failure risk (aHR = 21.7, 95% CI = 18.0-26.1) compared with the non-SLE cohort.
  
  
  CONCLUSIONS
  Patients with SLE are associated with an increased risk of incident respiratory failure, regardless of their age, sex, and pre-existing comorbidities; especially medical services with higher frequency.
authors.affiliation: Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi, Taiwan.|Chia Nan University of Pharmacy and Science, Tainan, Taiwan.|Meiho University, Pingtung, Taiwan.
authors.forename: Jun-Jun
authors.initials: JJ
authors.lastname: Yeh
authors.affiliation: Management Office for Health Data, China Medical University Hospital, Taichung, Taiwan.|College of Medicine, China Medical University, Taichung, Taiwan.
authors.forename: Yu-Chiao
authors.initials: YC
authors.lastname: Wang
authors.affiliation: Graduate Institute of Clinical Medicine Science, College of Medicine, China Medical University, Taichung, Taiwan.|Division of Rheumatology, Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan.
authors.forename: Jiunn-Horng
authors.initials: JH
authors.lastname: Chen
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: Wu-Huei
authors.initials: WH
authors.lastname: Hsu