Emergency department presentations for self-harm among Ontario Youth.

Bethell, Jennifer ; Bondy, Susan J. ; Lou, W.Y. Wendy 等

Self-harm refers to non-fatal self-poisoning or self-injury, irrespective of the apparent purpose. (1) Similar to non-fatal suicide-related behaviours, (2) self-harm encompasses suicide attempts as well as non-suicidal self-injury. Self-harm is a major risk factor for suicide, (3) the second-leading cause of death in 15-24 year-olds worldwide. (4) Self-harm among youth is also a public health issue in its own right: it is associated with health and psychosocial problems, (5) it is common (roughly 1 in 20 high school students reported an episode of self-harm in the previous year) (6) and the frequency peaks in the late teens. (7) In fact, US data showed self-harm was a factor in just over 700,000 emergency department presentations annually (8) and about a quarter of them were by teens. (9) However, there has been relatively little Canadian research on self-harm in youth. This may explain, at least in part, why self-harm has received less attention for public health action as it has in other countries. For example, Canada does not have a national suicide prevention strategy, (10) nationally-endorsed clinical guidelines for self-harm (such as those from the National Institute for Health and Clinical Excellence) (1) or a self-harm monitoring system, all of which have been implemented in England. (11)

This study used population-based health services data to describe emergency department presentations for self-harm among Ontario youth. Demographic and clinical characteristics were interpreted in the context of similar data reported from multi-site studies in other countries.

METHODS

Sampling procedures

Emergency department presentations were defined from the National Ambulatory Care Reporting System (NACRS). These data capture every emergency department visit; all legal residents are insured for acute and primary health care services and every hospital submitted NACRS emergency department data during the study period. All emergency department presentations by 12-17 year-old Ontario residents over the seven-year period between April 1, 2002 and March 31, 2009 were selected, excluding deaths on arrival or in the emergency department (n=406); scheduled visits (n=14,443); and those where the individual left without being seen (n=169). After these exclusions, there were 2,439,939 emergency department presentations by 910,756 individuals. Self-harm presentations were identified as a subset of these data, selected where any of the diagnoses indicated self-harm. Two definitions of self-harm were used to accommodate potential under-ascertainment: (12)

* Self-harm definition 1: any International Classification of Diseases, version 10(ICD-10) code for intentional self-harm (ICD-10: X60-84).

* Self-harm definition 2: as above, as well as any codes for poisoning, undetermined intent (ICD-10: Y10-19) or contact with sharp object, undetermined intent (ICD-10: Y28).

Measures

Age and sex were obtained from the NACRS record. Community size and neighbourhood income quintile were obtained using the individual's residential postal code and the Statistics Canada Postal Code Conversion File (PCCF). (13) For both measures, individuals were assigned to their dissemination area: a small, relatively stable geographic unit and the smallest standard geographic area for which census data are produced. Community size (the population, in 2006, of the larger community in which the individual resided) was categorized by the PCCF as: 1,500,000+; 500,000-1,499,999; 100,000-499,999; 10,000-99,999; <10,000 or missing. "Rural" residence was defined according to Statistics Canada's recommended definition of rural and small town, i.e., population <10,000. (14)

Neighbourhood income quintile (a measure of income of the individual's residential area, in 2006, relative to the larger community) was assigned by the PCCF using the mean income per person equivalent (household income, adjusted for household size), calculated for each dissemination area. Using this information, dissemination areas were ranked, within cities, towns or rural/small town areas, and the populations of each were divided into approximate fifths to create community-specific income quintiles. Method of self-harm was defined using external cause of injury codes listed on the NACRS record and categorized as: self-poisoning only (ICD-10: X60-69 [and/or ICD-10: Y10-19 under SH2]); self-cutting only (ICD-10: X78 [and/or ICD-10: Y28 under SH2]); other injuries only (ICD-10: X70-77; X79-84); or, multiple methods. Acuity was measured by a validated triage score, the Canadian Triage and Acuity Scale, (15) obtained from the NACRS record and recorded as resuscitation, emergent, urgent, semi-urgent, or non-urgent. Disposition from the emergency department was categorized as: admitted; transferred to another ED; left before visit completed (left without treatment or against medical advice); or, discharged.

Statistical analysis

Data were described with frequencies and proportions. Incidence rates were calculated, overall and according to demographic characteristics. The numerators were the number of self-harm presentations, including multiple events by the same person. The denominators were the amount of person-years, calculated by summing the annual population estimates (using 2006 census and intercensal estimates for age- and sex-specific estimates or the Registered Persons Database (16) for community size and neighbour hood income quintile specific estimates). Rates were expressed per 100,000 person-years with 95% confidence intervals (CIs) calculated to account for clustering from multiple events per person.17 All analyses were carried out using SAS version 9.1. (18)

Ethics approval was obtained from the Research Ethics Boards of St. Michael's and Sunnybrook Hospitals.

RESULTS

Over the 7-year period, among 12-17 year-olds in Ontario, there were 16,835 self-harm presentations by 12,907 individuals under self-harm definition 1 and 22,589 presentations by 17,557 individuals under self-harm definition 2. As shown in Table 1, the most common method of self-harm was self-poisoning only, then self-cutting only, other injuries only, or multiple methods. Nearly all self-poisonings involved medicinal agents, 10,383(93.4%) under self-harm definition 1 and 13,754(91.1%) under self-harm definition 2.

The overall incidence rate of emergency department presentations for self-harm by 12-17 year-olds was 239.0(95% CI: 233.1244.9) per 100,000 person-years under self-harm definition 1 and 320.7(95% CI: 314.0-327.4) per 100,000 person-years under self-harm definition 2. The sex-specific incidence rate estimates under self-harm definition 1 were 375.7(95% CI: 364.4-387.0) per 100,000 person-years for girls and 109.2(95% CI: 105.1-113.2) per 100,000 person-years for boys. The corresponding rates under self-harm definition 2 were 474.5(95% CI: 461.8-487.3) per 100,000 person-years for girls and 174.6(95% CI: 169.5-179.7) per 100,000 person-years for boys. Figure 1 shows the incidence rates increased with age in both boys and girls, but were always higher in girls. Figure 2 shows the incidence rates were highest in low-population areas (and vice versa). Figure 3 shows an inverse relationship between neighbourhood income quintile and self-harm presentations; that is, 12-17 year-olds living in the lowest-income neighbourhoods had the highest rates(and vice versa).

Table 2 shows that self-harm made up roughly 1 in 100 emergency department presentations among Ontario youth, but also made up a larger proportion of complex presentations; self-harm accounted for at least 1 in 20 presentations triaged as highest acuity (resuscitation/emergent) or admitted to hospital. The higher frequency of self-harm among girls and with increasing age was also reflected here; the proportion of total emergency department presentations related to self-harm was higher in girls than in boys and increased with age.

DISCUSSION

These data show self-harm presentations among Ontario youth are consistent with those reported from other countries. In particular, incidence rates are strikingly similar to those in the United States (19) and Ireland. (20) While rates reported from England are considerably higher, (11) each of these international data have consistently found girls outnumber boys; frequency increases with age; and method of self-harm is most often self-poisoning, then self-cutting (in fact, similar to the results from England, a previous study showed Ontario youth most often self-poisoned with analgesics, typically acetaminophen, then antidepressants (21)). The association with neighbourhood income has also been reported among youth in England, (22) and is thought to involve mechanisms including family (genetic and environmental factors), exposure to violence, lifestyle(e.g., substance abuse) and housing. Conversely, these Ontario data showed that about one third of youth who presented to the emergency department for self-harm were admitted, whereas admission occurred in about half in the United States to nearly three quarters in England. This difference may reflect differences in acuity and/or health service availability, or possibly the guidance provided to clinicians in American (23) and British (1) guidelines around the decision to admit.

New findings were also presented here with respect to incidence rates by community size; the rate was lowest among youth living in Toronto(Ontario's only city with a population >1,500,000) and highest among those living in rural and low-population areas.

Although people living in Ontario's rural areas tend to use the emergency department more often than those in the rest of the province, (24) given that the pattern of self-harm presentation rates mirrors those of Canadian suicide rates, (25) it seems unlikely to be the only explanation. More plausible hypotheses may overlap with the mechanisms proposed to explain these higher suicide rates in rural areas. (26) For example, socio-economic disadvantage, differences in service delivery systems(e.g., high-population areas' better access to potentially-preventive mental health services) and the populations' ethnic composition may be important factors. With respect to the latter, it may be that patterns seen in suicide rates, such as the "healthy immigrant effect" (27) or the high suicide rate among Aboriginal populations, (28) extend to self-harm (although it is also important to note that these findings do not apply evenly across these diverse populations (29,30)).

Limitations

Although administrative data are a vital source of information for health policy and planning and offer numerous advantages for studying self-harm, key limitations must be acknowledged. First, of those who present to the emergency department, the self-inflicted nature of their injury or poisoning may go undetected or unrecorded. For example, the individual may be hesitant to disclose and/or the clinician may be reluctant to document self-harm. While an attempt was made to account for some of the probable under-ascertainment of self-harm by including presentations coded as undetermined, (12) it is still unclear which definition of self-harm is most accurate. Second, it was impossible to disaggregate self-harm by suicidal intent; such information is not included in the current NACRS data and ICD does not distinguish suicidal and non-suicidal acts. Researchers are increasingly acknowledging that, although highly associated, attempted suicide and non-suicidal self-injury do differ and future research should endeavour to distinguish them as such. (31) A system which also incorporates a third category-that where the suicidal intent is undetermined (2) -may also be most useful given difficulties in assessing suicidal intent. (32) Third, this study analyzed self-harm presentations to the emergency department, so results cannot be generalized to those who do not seek this care. Survey data suggest that those who present to hospital likely represent a more suicidal subset of youth who self-harm; the intent to die was the strongest predictor of health service use following self-harm (in both boys and girls). (6)

Generalizability

Emergency department data provide more representative information than inpatient admissions;(12) less than half of those who present to the emergency department for self-harm are admitted and admission is associated with various factors, including method of self-harm. (21) The epidemiology and characteristics of emergency department presentations for self-harm among Ontario youth are quite consistent with those reported from other countries, suggesting generalizability of study results between populations. However, it is unclear whether these findings extend across Canada. Canada does not currently maintain a national emergency department data system; the 2011 Health Indicators report from the Canadian Institute for Health Information and Statistics Canada, the first ever on self-harm, reported mainly on inpatient admissions. The emergency department data that were included, from Ontario, Alberta and the Yukon, suggested differences between these provinces and territory in the frequency of self-harm presentations (including specifically among teenage girls). (33)

CONCLUSIONS AND FUTURE DIRECTIONS

Self-harm is an important public health issue in Canada, requiring a comprehensive prevention approach. For example, addressing the strong association between self-harm and suicide (and the even-higher risk among those who repeatedly present to the emergency department for self-harm), (34) the World Health Organization's framework for public health action in suicide prevention specifically recognizes the importance of assessing and managing those who present to a health care facility for self-harm. (35) In this regard, roles for primary care, including involvement in the transition from the emergency department to aftercare, (36) also seem critical.

Ontario has useful existing data and infrastructure to study emergency department presentations for self-harm: there is near-complete coverage of the population; all hospitals submit emergency department data; and health services, including inpatient admissions, emergency department presentations, and physician visits, can be individually linked over time. Emergency department presentations for self-harm have been interpreted as a measure of access to mental health services, (33) so these data can offer valuable opportunities to evaluate strategies to improve mental health outcomes in youth.

Future research should address the reasons for the geographic differences in self-harm, and in particular, explanations for the finding that emergency department presentations for self-harm are more common among youth living in rural and low-population areas. Given that the highest youth suicide rates in Canada are among those living in rural areas, assessing the factors that contribute to this pattern could have broader implications for prevention.

REFERENCES

(1.) National Collaborating Centre for Mental Health (UK) commissioned by the National Institute for Clinical Excellence. Self-harm. The Short-term Physical and Psychological Management and Secondary Prevention of Self-harm in Primary and Secondary Care. Leicester, UK: British Psychological Society, 2004.

(2.) Silverman M, Berman AL, Sanddal ND, O'Carroll PW, Joiner TE. Rebuilding the Tower of Babel: A revised nomenclature for the study of suicide and suicidal behaviors Part 2: Suicide-related ideations, communications, and behaviors. Suicide Life Threat Behav 2007;37:264-77.

(3.) Bridge JA, Goldstein TR, Brent DA. Adolescent suicide and suicidal behavior. J Child Psychol Psychiatry 2006;47:372-94.

(4.) Suicide prevention (SUPRE). World Health Organization 2011. Available at: http://www.who.int/mental_health/prevention/suicide/suicideprevent/en/ (Accessed April 18, 2012).

(5.) Patton GC, Harris R, Carlin JB, Hibbert ME, Coffey C, Schwartz M, et al. Adolescent suicidal behaviours: A population-based study of risk. Psychol Med 1997;27:715-24.

(6.) Ystgaard M, Arensman E, Hawton K, Madge N, van Heeringen K, Hewitt A, et al. Deliberate self-harm in adolescents: Comparison between those who receive help following self-harm and those who do not. J Adolesc 2009;32:875 91.

(7.) Colman I, Yiannakoulias N, Schopflocher D, Svenson LW, Rosychuk RJ, Rowe BH. Population-based study of medically-treated self-inflicted injuries. Can J Emerg Med 2004;6:313-20.

(8.) Harman JS, Scholle SH, Edlund MJ. Emergency department visits for depression in the United States. Psychiatric Serv 2004;55:937-39.

(9.) Centers for Disease Control and Prevention (CDC). Nonfatal self-inflicted injuries treated in hospital emergency departments--United States, 2000. MMWR 2002;51:436-38.

(10.) Department of Health. National suicide prevention strategy for England. 2002.

(11.) Hawton K, Bergen H, Waters K, Ness J, Cooper J, Steeg S, Kapur N. Epidemiology and nature of self-harm in children and adolescents: Findings from the multicentre study of self-harm in England. Eur Child Adolesc Psychiatry 2012;21(7):369-77.

(12.) Bethell J, Rhodes AE. Identifying deliberate self-harm in emergency department data. Health Reports 2009;20:35-42.

(13.) Statistics Canada. Postal Code Conversion File (PCCF), Reference Guide. 2008.

(14.) du Plessis V, Beshiri R, Bollman R. Definitions of rural. Statistics Canada, Rural and Small Town Canada Analysis Bulletin, 2001.

(15.) Beveridge R, Ducharme J, Janes L, Beaulieu S, Walter S. Reliability of the Canadian emergency department triage and acuity scale: Interrater agreement. Ann Emerg Med 1999;34:155-59.

(16.) Iron K, Zagorski B, Sykora K, Manuel D. Living and Dying in Ontario: An Opportunity for Improved Health Information. Toronto, ON: Institute for Clinical Evaluative Sciences, 2008.

(17.) Stukel TA, Glynn RJ, Fisher ES, Sharp SM, Lu-Yao G, Wennberg JE. Standardized rates of recurrent outcomes. Stats Med 1994;13:1781-91.

(18.) SAS Institute Inc. SAS version 9.1. 2002.

(19.) Olfson M, Gameroff M, Marcus S, Greenberg T, Shaffer D. Emergency treatment of young people following deliberate self-harm. Arch Gen Psychiatry 2005;62:1122-28.

(20.) Perry IJ, Corcoran P, Fitzgerald AP, Keeley HS, Reulbach U, Arensman E. The incidence and repetition of hospital-treated deliberate self harm: Findings from the World's First National Registry. PLoS ONE2012;7:e31663.

(21.) Rhodes A, Bethell J, Spence J, Links P, Streiner D, Jaakkimainen RL. Age-sex differences in medicinal self-poisonings. Soc Psychiat Epidemiol 2008;43:642 52.

(22.) Ayton A, Rasool H, Cottrell D. Deliberate self-harm in children and adolescents: Association with social deprivation. Eur Child Adolesc Psychiatry 2003;12:303-7.

(23.) American Academy of Child and Adolescent Psychiatry. Summary of the practice parameters for the assessment and treatment of children and adolescents with suicidal behavior. J Am Acad Child Adolesc Psychiatry 2001;40:495-99.

(24.) Khan Y, Glazier RH, Moineddin R, Schull MJ. A Population-based study of the association between socioeconomic status and emergency department utilization in Ontario, Canada. Acad Emerg Med 2011;18:836-43.

(25.) DesMeules M, Pong R, Lagace C, Heng D, Manuel D, Pitblado R, et al. How Healthy Are Rural Canadians? An Assessment of Their Health Status and Health Determinants. Ottawa, ON: Canadian Institute for Health Information, 2006.

(26.) Judd F, Cooper AM, Fraser C, Davis J. Rural suicide--people or place effects? Aust N Z J Psychiatry 2006;40:208-16.

(27.) Malenfant E. Suicide in Canada's immigrant population. Health Reports 2004;15:9-17.

(28.) Health Canada. Acting On What We Know: Preventing Youth Suicide in First Nations. Public Health Agency of Canada, 2003. Available at: http://www.hcsc.gc.ca/fniah- spnia/pubs/promotion/_suicide/prev_youth-jeunes/index- eng.php#s111 (Accessed April 18, 2012).

(29.) Bursztein Lipsicas C, Makinen IH. Immigration and suicidality in the young. Can J Psychiatry 2010;55:274-81.

(30.) Chandler MJ, Lalonde C. Cultural continuity as a hedge against suicide in Canada's First Nations. Transcultural Psychiatry 1998;35:191-219.

(31.) Kutcher S, Szumilas M. Distinguishing suicide attempts from nonsuicidal self-harming behaviors. J Am Acad Child Adolesc Psychiatry 2009;48:1039.

(32.) Hasley JP, Ghosh B, Huggins J, Bell MR, Adler LE, Shroyer AL. A review of "suicidal intent" within the existing suicide literature. Suicide Life Threat Behav 2008;38:576-91.

(33.) Statistics Canada, Canadian Institute for Health Information. Health Indicators 2011. 2011.

(34.) Zahl DL, Hawton K. Repetition of deliberate self-harm and subsequent suicide risk: Long-term follow-up study of 11,583 patients. Br J Psychiatry 2004;185:70-75.

(35.) World Health Organization. Public Health Action for the Prevention of Suicide. A Framework. Geneva: WHO, 2012.

(36.) Newton AS, Hamm MP, Bethell J, Rhodes A, Bryan CJ, Tjosvold L, et al.

Pediatric suicide-related presentations: A systematic review of mental health care in the emergency department. Ann Emerg Med 2010;56:649-59.

Received: October 25, 2012

Accepted: January 5, 2013

Jennifer Bethell, PhD, [1] Susan J. Bondy, PhD, [2] W.Y. Wendy Lou, PhD, [3] Astrid Guttmann, MDCM, MSc, [4] Anne E. Rhodes, PhD [5]

Author Affiliations

[1.] Suicide Studies Research Unit, St. Michael's Hospital; Dalla Lana School of Public Health, University of Toronto, Toronto, ON

[2.] Associate Professor, Dalla Lana School of Public Health, University of Toronto, Toronto, ON

[3.] Canada Research Chair in Statistical Methods for Health Care; Professor, Dalla Lana School of Public Health, University of Toronto, Toronto, ON

[4.] Associate Professor, Department of Paediatrics and Department of Health Policy, Management and Evaluation, University of Toronto; Senior Scientist, Institute for Clinical Evaluative Sciences; Staff Physician, Hospital for Sick Children, Toronto, ON

[5.] Research Scientist, Suicide Studies Research Unit, St. Michael's Hospital; Associate Professor, Department of Psychiatry and Dalla Lana School of Public Health, University of Toronto; Adjunct Scientist, Institute for Clinical Evaluative Sciences, Toronto, ON

Correspondence: Jennifer Bethell, Suicide Studies Research Unit, St. Michael's Hospital, 30 Bond Street, Toronto, ON M5B 1W8, E-mail: [email protected] Acknowledgement: Dr. Bethell was supported by a Studentship from the Ontario Mental Health Foundation. The data were accessed through the Institute for Clinical Evaluative Sciences, which is funded by an annual grant from the Ontario Ministry of Health and Long-Term Care.

Disclaimer: The opinions, results and conclusions reported in this paper are those of the authors and are independent from the funding sources. No endorsement is intended or should be inferred. Conflict of Interest: None to declare.

Table 1. Methods of Self-harm Identified in Emergency Department
Presentations by 12-17 Year-olds in the Province of Ontario
Between April 1, 2002 and March 31, 2009

                      Self-harm        Self-harm
                      Definition 1     Definition 2
Method of Self-harm     n        %       n        %

Self-poisoning only   11,113   66.0%   15,102   66.9%
Self-cutting only      4204    25.0%    5856    25.9%
Other injuries only    1336    7.9%     1325    5.9%
Multiple methods        182    1.1%      306    1.4%

Self-harm definition 1 (SH1): records that list any International
Classification of Diseases, version 10 (ICD-10) code for intentional
self-harm (ICD-10: X60-84).

Self-harm definition 2: as with SH1, as well as records that list
any codes for poisoning, undetermined intent (ICD-10: Y10-19) or
contact with sharp object, undetermined intent (ICD-10: Y28).

Table 2. Self-harm as a Proportion of All Emergency Department
Presentations by 12-17 Year-olds in the Province of Ontario
Between April 1, 2002 and March 31, 2009

Variable                     All Emergency    Self-harm
                              Department     Definition 1
                             Presentations

                               [n.sub.0]      [n.sub.1]     %[n.sub.1]/
                                                             [n.sub.0]

Overall                         2,439,939         16,835          0.7%
Sex
  Girls                         1,182,124         12,892          1.1%
  Boys                          1,257,754           3943          0.3%
Age (years)
  12-15                         1,482,905           8182          0.6%
  16-17                           957,034           8653          0.9%
Canadian Triage
and Acuity Scale
  Resuscitation/emergent          137,076           6500          4.7%
  Urgent                          711,301           7553          1.1%
  Non-/semi-urgent              1,591,562           2782          0.2%
Disposition
  Admitted                         96,087           5599          5.8%
  Discharged                    2,210,378         10,234          0.5%
  Transferred                      21,943            705          3.2%
  Left before visit               111,531            297          0.3%

Variable                     All Emergency    Self-harm
                              Department     Definition 2
                             Presentations

                               [n.sub.0]      [n.sub.2]     %[n.sub.2]/
                                                             [n.sub.0]

Overall                         2,439,939         22,589          0.9%
Sex
  Girls                         1,182,124         16,282          1.4%
  Boys                          1,257,754           6307          0.5%
Age (years)
  12-15                         1,482,905         11,052          0.7%
  16-17                           957,034         11,537          1.2%
Canadian Triage
and Acuity Scale
  Resuscitation/emergent          137,076           8366          6.1%
  Urgent                          711,301           9822          1.4%
  Non-/semi-urgent              1,591,562           4401          0.3%
Disposition
  Admitted                         96,087           6537          6.8%
  Discharged                    2,210,378         14,689          0.7%
  Transferred                      21,943            822          3.7%
  Left before visit               111,531            541          0.5%
    completed

Self-harm definition 1 (SH1): records that list any International
Classification of Diseases, version 10 (ICD-10) code for intentional
self-harm (ICD-10: X60-84).

Self-harm definition 2: as with SH1, as well as records that list
any codes for poisoning, undetermined intent (ICD-10: Y10-19) or
contact with sharp object, undetermined intent (ICD-10: Y28).

Figure 1. Incidence rate (and 95% confidence interval) of emergency
department presentations for self-harm, by age and sex, for
12-17 year-olds in the Province of Ontario between April 1,
2002 and March 31, 2009
                         Age (years)

               12      13      14      15      16      17

Girls (SH2)   77.9   215.7    501.6   659.1   713.2   679.2
Girls (SH1)   56.5   172.5    393.5   527.6   564.8   539.1
Boys (SH2)    47.0    76.1    129.4   204.8   266.4   322.7
Boys (SH1)    20.5    39.0     74.9   134.2   177.7   207.7

Figure 2. Incidence rate (and 95% confidence interval) of emergency
department presentations for self-harm, by community size,
for 12-17 year-olds in the Province of Ontario between
April 1, 2002 and March 31, 2009

              Community size (population)

0.0   1,500,000+    500,000-1,499,999   100,000-499,999
SH2     185.0               351.9             356.7
SH1     131.6               279.3             277.3

              Community size (population)

0.0   10,000-99,999      <10,000
SH2     471.4             439.9
SH1     330.5             323.0

Figure 3. Incidence rate (and 95%
confidence interval) of emergency
department presentations for self-harm,
by neighbourhood income quintile, for
12-17 year-olds in the Province of
Ontario between April 1, 2002 and March
31, 2009
               Neighbourhood income quintile

      1 (lowest)      2       3       4    5 (highest)

SH2     346.3      333.9   306.5   277.5      260.1
SH1     259.9      247.1   229.5   207.3      191.8