title: Asthma, corticosteroid use and schizophrenia: A nationwide population-based study in Taiwan.
abstract: OBJECTIVE
  Asthma and corticosteroid use have been implicated as possible risk factors for schizophrenia. The retrospective cohort study herein aimed to investigate the association between asthma, corticosteroid use, and schizophrenia.
  
  
  METHODS
  Longitudinal data (2000 to 2007) from adults with asthma (n = 50,046) and without asthma (n = 50,046) were compared on measures of schizophrenia incidence using Taiwan's National Health Insurance Research Database (NHIRD). Incidence of schizophrenia diagnosis (ICD-9 codes 295.XX) between 2000 and 2007 were compared between groups. Competing risk-adjusted Cox regression analyses were conducted, adjusting for sex, age, residence, socioeconomic status, corticosteroid use, outpatient and emergency room visit frequency, Charlson comorbidity index, and total length of hospital stays days for any disorder.
  
  
  RESULTS
  Of the 75,069 subjects, 238 received a diagnosis of schizophrenia. The mean (SD) follow-up interval for all subjects was 5.8 (2.3) years. After adjusting for potential confounding factors, asthma was associated with significantly greater hazard ratio for incident schizophrenia 1.40 (95% CI = 1.05, 1.87). Additional factors associated with greater incidence of schizophrenia were rural residence, lower economic status, and poor general health. Older age (i.e. ≥65 years) was negatively associated with schizophrenia incidence. Corticosteroid use was not associated with increased risk for schizophrenia.
  
  
  CONCLUSIONS
  Asthma was associated with increased risk for schizophrenia. The results herein suggest that a convergent disturbance in the immune-inflammatory system may contribute to the pathoetiology of asthma and schizophrenia.
authors.affiliation: School of Medicine, Chung Shan Medical University, Taichung, Taiwan.
authors.forename: Wei-Chen
authors.initials: WC
authors.lastname: Wang
authors.affiliation: Department of Psychiatry, Wan Fang Hospital and School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
authors.forename: Mong-Liang
authors.initials: ML
authors.lastname: Lu
authors.affiliation: Department of Psychiatry, Chang Gung Medical Foundation, Chiayi Chang Gung Memorial Hospital, Chiayi, Taiwan.|School of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Vincent Chin-Hung
authors.initials: VC
authors.lastname: Chen
authors.affiliation: Department of Health, Tsaotun Psychiatric Center, Nantou, Taiwan.
authors.forename: Mei-Hing
authors.initials: MH
authors.lastname: Ng
authors.affiliation: Department of Speech, Language Pathology and Audiology, Chung Shan Medical University, Taichung, Taiwan.
authors.forename: Kuo-You
authors.initials: KY
authors.lastname: Huang
authors.affiliation: School of Medicine, Chung Shan Medical University, Taichung, Taiwan.|Department of Psychiatry, Chung Shan Medical University Hospital, Taichung, Taiwan.
authors.forename: Ming-Hong
authors.initials: MH
authors.lastname: Hsieh
authors.affiliation: Department of Respiratory Therapy, Chang-Gung University, Taoyuan, Taiwan.|Department of Pulmonary and Critical Care Medicine, Chang Gung Medical Foundation, Chiayi Chang-Gung Memorial Hospital, Chiayi, Taiwan.
authors.forename: Meng-Jer
authors.initials: MJ
authors.lastname: Hsieh
authors.affiliation: Mood Disorders Psychopharmacology Unit, University Health Network, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Roger S
authors.initials: RS
authors.lastname: McIntyre
authors.affiliation: Mood Disorders Psychopharmacology Unit, University Health Network, University of Toronto, Toronto, Ontario, Canada.|Department of Psychiatry and Pharmacology, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Yena
authors.initials: Y
authors.lastname: Lee
authors.affiliation: Department of Health Promotion and Health Education, National Taiwan Normal University, Taipei, Taiwan.
authors.forename: Charles Tzu-Chi
authors.identifier: http://orcid.org/0000-0002-5958-3680
authors.initials: CT
authors.lastname: Lee
mesh_terms: D000293:Adolescent; D000305:Adrenal Cortex Hormones / Q000627:therapeutic use*; D000328:Adult; D000368:Aged; D001249:Asthma / Q000188:drug therapy* / Q000453:epidemiology*; D015986:Confounding Factors, Epidemiologic; D005260:Female; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009313:National Health Programs / Q000706:statistics & numerical data; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors; D012559:Schizophrenia / Q000453:epidemiology*; D013624:Taiwan / Q000453:epidemiology; D055815:Young Adult
chemical_list: D000305:Adrenal Cortex Hormones