Incidence Rates of Deliberate Self-Harm in Denmark 1994-2011.
BACKGROUND
The validity and reliability of suicide statistics have been questioned and few nationwide studies of deliberate self-harm have been presented.


OBJECTIVE
To calculate rates of deliberate self-harm in Denmark in order to investigate trends and assess the reliability of hospital records.


METHODS
A register study based on all individuals recorded with an episode of deliberate self-harm or probable deliberate self-harm in nationwide registers during 1994-2011.


RESULTS
A substantial difference in the rates of deliberate self-harm and probable deliberate self-harm was noted for both genders. The average incidence rate of deliberate self-harm for women and men was 130.7 (95% CI = 129.6-131.8) per 100,000 and 86.9 (95% CI = 86.0-87.8) per 100,000, respectively. The rates of deliberate self-harm for women increased from 137.6 (95% CI = 132.9-142.3) per 100,000 in 1994 to 152.7 (95% CI = 147.8-157.5) in 2011. For a subgroup of younger women aged 15-24 years, an almost threefold increase was observed, IRR = 2.5 (95% CI = 2.4-2.7). The most frequently used method was self-poisoning.


CONCLUSIONS
The rates of deliberate self-harm and probable deliberate self-harm differed significantly. An increased incidence of deliberate self-harm among young Danish women was observed, despite detection bias. An improved registration procedure of suicidal behavior is needed.
1 Research Unit, Mental Health Centre Copenhagen, Capital Region of Denmark, Denmark.|2 Faculty of Health Sciences, University of Copenhagen, Capital Region of Denmark, Denmark.
Britt
B
Reuter Morthorst
3 Department of Psychiatry, Region of Southern Denmark, Aabenraa, Denmark.
Bodil
B
Soegaard
1 Research Unit, Mental Health Centre Copenhagen, Capital Region of Denmark, Denmark.|2 Faculty of Health Sciences, University of Copenhagen, Capital Region of Denmark, Denmark.
Merete
M
Nordentoft
1 Research Unit, Mental Health Centre Copenhagen, Capital Region of Denmark, Denmark.|4 Department of Mental Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
Annette
A
Erlangsen
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D012042:Registries; D012307:Risk Factors; D012737:Sex Factors; D013405:Suicide / Q000706:statistics & numerical data*; D013406:Suicide, Attempted / Q000706:statistics & numerical data*; D055815:Young Adult
deliberate self-harm; hospital records; incidence rates; nationwide; suicidal behavior