title: Age-specific suicide mortality following non-fatal self-harm: national cohort study in Sweden.
abstract: BACKGROUND
  Possible age-related differences in risk of completed suicide following non-fatal self-harm remain unexplored. We examined associations between self-harm and completed suicide across age groups of self-harming patients, and whether these associations varied by violent index method, presence of mental disorder, and repeated self-harm.
  
  
  METHODS
  The design was a cohort study with linked national registers in Sweden. The study population comprised individuals aged ⩾10 years hospitalized during 1990-1999 due to non-fatal self-harm (n = 53 843; 58% females) who were followed for 9-19 years. We computed hazard ratios (HRs) across age groups (age at index self-harm episode), with time to completed suicide as outcome.
  
  
  RESULTS
  The 1-year HR for suicide among younger males (10-19 years) was 14.6 [95% confidence interval (CI) 4.1-51.9] for violent method and 8.4 (95% CI 1.8-40.0) for mental disorder. By contrast, none of the three potential risk factors increased the 1-year risks in the youngest females. Among patients aged ⩾20 years, the 1-year HR for violent method was 4.6 (95% CI 3.8-5.4) for males and 10.4 (95% CI 8.3-13.0) for females. HRs for repeated self-harm during years 2-9 of follow-up were higher in 10- to 19-year-olds (males: HR 4.0, 95% CI 2.0-7.8; females: HR 3.7, 95% CI 2.1-6.5). The ⩾20 years age groups had higher HRs than the youngest, particularly for females and especially within 1 year.
  
  
  CONCLUSIONS
  Violent method and mental disorder increase the 1-year suicide risk in young male self-harm patients. Further, violent method increases suicide risk within 1 year in all age and gender groups except the youngest females. Repeated self-harm may increase the long-term risk more in young patients. These aspects should be accounted for in clinical suicide risk assessment.
authors.affiliation: Department of Clinical Neuroscience,Centre for Psychiatry Research,Karolinska Institutet,Stockholm,Sweden.
authors.forename: D
authors.initials: D
authors.lastname: Tidemalm
authors.affiliation: Department of Clinical Neuroscience,Centre for Psychiatry Research,Karolinska Institutet,Stockholm,Sweden.
authors.forename: K
authors.initials: K
authors.lastname: Beckman
authors.affiliation: Department of Clinical Neuroscience,Centre for Psychiatry Research,Karolinska Institutet,Stockholm,Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Dahlin
authors.affiliation: Division of Insurance Medicine,Department of Clinical Neuroscience,Karolinska Institutet,Stockholm,Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Vaez
authors.affiliation: Department of Medical Epidemiology and Biostatistics,Karolinska Institutet,Stockholm,Sweden.
authors.forename: P
authors.initials: P
authors.lastname: Lichtenstein
authors.affiliation: Department of Medical Epidemiology and Biostatistics,Karolinska Institutet,Stockholm,Sweden.
authors.forename: N
authors.initials: N
authors.lastname: Långström
authors.affiliation: Department of Clinical Neuroscience,Centre for Psychiatry Research,Karolinska Institutet,Stockholm,Sweden.
authors.forename: B
authors.initials: B
authors.lastname: Runeson
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D002648:Child; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D018570:Risk Assessment; D012307:Risk Factors; D016728:Self-Injurious Behavior / Q000453:epidemiology*; D017678:Sex Distribution; D013405:Suicide / Q000706:statistics & numerical data*; D013548:Sweden / Q000453:epidemiology; D055815:Young Adult
keywords: risk factors