title: Asthma and self-harm: a population-based cohort study in Taiwan.
abstract: OBJECTIVE
  Few studies have investigated the relationship between asthma and suicidality-related outcomes in the world. We sought to investigate the association between asthma and risk of non-fatal self-harm in a large national sample.
  
  
  METHODS
  Cases aged 10years and over were identified from Taiwan's National Health Insurance Research Database with a new primary diagnosis of asthma (ICD-9:493) between 2000 and 2008. Case status required the presence of any inpatient diagnosis of asthma and/or at least two recorded diagnoses and 1year duration of asthma in outpatient services. These 27,781 cases were compared to 138,905 sex- and age-matched controls and both groups were followed until end of 2008 for instances of self-harm, defined as ICD-9 codes E950-E959 (self-harm causes) and E980-E989 (undetermined causes). Competing risk adjusted Cox regression analyses were applied, adjusting for sex, age, residence (urban/rural), insurance premium, episode of psychiatric disease, montelukast, Charlson comorbidity index and mortality.
  
  
  RESULTS
  Of the 166,686 subjects, 445 carried out self-harm during a mean (SD) follow-up period of 5.84 (2.35) years. Asthma (hazard ratio=1.70, 95% CI: 1.35-2.14), age, residence, episode of psychiatric disease and Charlson comorbidity index were independent risks on self-harm in the fully adjusted model.
  
  
  CONCLUSIONS
  Asthma was associated with increased risk of self-harm in this population, independent of a number of potential confounding factors including montelukast use. This reinforces the need to consider mental health in routine asthma care, and to consider asthma as a potentially important stressor in people with comorbid mental disorder.
authors.affiliation: Department of Psychiatry, Chung Shan Medical University Hospital, Taichung, Taiwan; Department of Psychiatry, School of Medicine, Chung Shan Medical University, Taichung, Taiwan. Electronic address: hjcch@yahoo.com.tw.
authors.forename: Vincent Chin-Hung
authors.initials: VC
authors.lastname: Chen
authors.affiliation: Department of Public Health, Kaohsiung Medical University, Kaohsiung, Taiwan. Electronic address: wangtn@kmu.edu.tw.
authors.forename: Tsu-Nai
authors.initials: TN
authors.lastname: Wang
authors.affiliation: Department of Psychiatry, Chung Shan Medical University Hospital, Taichung, Taiwan; Department of Psychiatry, School of Medicine, Chung Shan Medical University, Taichung, Taiwan. Electronic address: je2tezy@yahoo.com.tw.
authors.forename: Yin-To
authors.initials: YT
authors.lastname: Liao
authors.affiliation: Department of Psychiatry, Chung Shan Medical University Hospital, Taichung, Taiwan; Department of Psychiatry, School of Medicine, Chung Shan Medical University, Taichung, Taiwan. Electronic address: jamaalbest@gmail.com.
authors.forename: Tzu Chin
authors.initials: TC
authors.lastname: Lin
authors.affiliation: King's College London, Institute of Psychiatry, London, UK. Electronic address: robert.stewart@kcl.ac.uk.
authors.forename: Robert
authors.initials: R
authors.lastname: Stewart
authors.affiliation: Department of Public Health, Kaohsiung Medical University, Kaohsiung, Taiwan. Electronic address: Charles@kmu.edu.tw.
authors.forename: Charles Tzu-Chi
authors.initials: CT
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D000553:Ambulatory Care; D001249:Asthma / Q000453:epidemiology* / Q000523:psychology*; D015331:Cohort Studies; D015897:Comorbidity; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D001523:Mental Disorders / Q000453:epidemiology; D008875:Middle Aged; D016017:Odds Ratio; D016016:Proportional Hazards Models; D018570:Risk Assessment; D016728:Self-Injurious Behavior / Q000453:epidemiology* / Q000209:etiology; D013405:Suicide / Q000706:statistics & numerical data*; D013624:Taiwan / Q000453:epidemiology
keywords: Asthma; Charlson comorbidity index; Psychiatric disease; Self-harm