Emergency Department Visits for Self-Inflicted Injuries in Adolescents

Discussion

Adolescent ED visits for SII increased from 2009 to 2012, and patients with SII injuries had a dramatically higher risk of dying compared with those with other injuries. These findings highlight the importance of addressing and preventing self-harm behavior in this age group. Although multiple studies have highlighted that rates of SII are increasing in both adolescents and adults,^4,5 this study represents the most current analysis in an adolescent population. Our finding that cut/pierce was the most common mechanism differs from an earlier study using data from the NTDB⁶ and may indicate a shift in self-harm behavior in youth. A positive finding was a significant decrease in adolescent ED visits for self-inflicted firearm injuries, which may reflect a rise in strategies focused on reducing access to highly lethal means, including firearms, in suicidal youth (ie, lethal means restriction). There is strong evidence to support using the ED as a setting for injury prevention and intervention,¹⁷ and efforts have been made to promote the use of lethal means restriction counseling by ED providers, as this approach has been shown to reduce suicide rates.^18,19

Although self-harm behavior is a major public health problem, there is limited research on the epidemiology of ED visits for SII in adolescents. Three studies have examined SII behavior in youth presenting to EDs in the United States, with all examining data from 2007 or earlier.^6–8 Similar to our findings, female youth have been shown to be more likely to visit the ED for SII injuries compared with males,^7,8 but males have been shown to have a greater risk of dying from their injuries, likely because they tend to use more lethal mechanisms such as firearms.^6,7 Adolescents with any comorbid condition were at increased risk of SII in our study, and those with ≥2 comorbid conditions had nearly 3 times the odds, findings that may warrant increased attempts at prevention in these young people. We also found that the specific comorbid conditions of obesity and alcoholism were associated with increased risk of an SII, results that align with other research on self-harm behavior in adolescents.^14,15

We found that risk of SII was lower in African American adolescents than in white adolescents, which differs from previous research. Cooper et al found that rates of self-harm in patients presenting to EDs in 3 English cities were highest in young black females,²⁰ whereas Ting et al found that blacks in the United States had higher population rates of ED visits for attempted suicide and SII compared with whites.⁴ Our finding that Asian adolescents were more likely to visit the ED for an SII is unique in the United States, although a study in England found that South Asian females were more likely to visit EDs for SII.²¹ The lack of agreement in findings on SII risk across studies may be influenced by variances in the socioeconomic profiles experienced by a specific racial/ethnic group residing in one area versus another.²⁰

Only 4.9% of adolescents in our cohort with an SII had a diagnosis code for a mental health disorder. These findings differ from 2 other studies that reported >50% of ED visits for SII carrying a diagnosis for a mental health disorder.^8,10 To have data reported to the NTDB, a patient must sustain at least 1 traumatic injury. Therefore, not all ED patients have data reported to the NTDB, likely explaining why there were fewer mental health diagnoses in our study. It is still surprising that so few patients with an SII had a mental health disorder diagnosed during their visit. The low number of patients with a recorded diagnosis is of concern, as this indicates missed opportunities to document mental health issues and link patients with follow-up mental health care.

Although only a small percentage of visits to EDs are for SII, as our results and previous authors have documented, these patients are at increased risk of death.^22,23 We found that adolescents in the self-pay insurance category had higher odds of dying from their SII injuries than those with private insurance. Two recent studies have also found higher odds of mortality in trauma patients who self-pay.^24,25 It could be assumed that adolescents in the self-pay category include uninsured patients,²⁴ and these adolescents may represent families who do not qualify for public assistance and cannot afford insurance on their own. Adolescents without any type of insurance may have extremely limited access to mental health services, leading to a higher likelihood of long-term untreated mental health issues, and possibly a higher risk of death.

The low percentage of SII visits for poisoning found in this analysis is in part because an injury due to ingestion is not coded as trauma by the NTDB data standard and thus is not normally reported within this dataset. This does not mean poisonings are never reported, as shown by our analysis, but the numbers we report in no way represent the true number of self-injuries due to poisoning seen by the EDs reporting to the NTDB. Branco et al analyzed data from the NTDB, years 2002 to 2006, and still found poisoning to be the most common method in females even with the limited reporting of this SII.⁶ Because there has been no change in documentation of poisoning cases since the NTDB started collecting data, a comparison of our results regarding rates of ED visits for poisoning to the results of Branco et al may reflect a decrease in self-injury through poisoning in adolescents. A much higher percentage of adolescents visited the ED for cut/pierce injuries in our cohort compared with Branco et al, which may reflect a rise in self-mutilation behavior in adolescents.

Our study is subject to several limitations. The NTDB is a secondary source of data that treats each patient as an isolated occurrence. Thus, we cannot determine if some SIIs were repeat visits, and we were limited to the patient information documented by participating hospitals, resulting in an inability to determine suicidal versus nonsuicidal behavior. The NTDB is not a nationally representative sample. However, all ACS-verified Level I and Level II trauma centers are required to submit data to the NTDB, providing us with insight specific to these centers. The NTDB collects data on trauma cases only, and our findings are not generalizable to all ED visits for self-harm behavior. As mentioned previously, not all poisoning cases are reported to the NTDB, and these findings should be interpreted with caution. Alcoholism and obesity were recorded for only a small number of patients, and it can be assumed that many adolescents in our cohort were misclassified as not having these comorbid conditions when they actually did. It is possible that adolescents with SII visits were more likely to be diagnosed with alcoholism or obesity if these conditions were thought to be causally linked with the self-harm behavior. However, other studies have found associations between alcoholism or obesity and SII,^14,15 providing support for our findings.