Direct Self-Injurious Behavior (D-SIB) and Life Events among Vocational School and High School Students

Although several studies have recently assessed direct self-injurious behavior (D-SIB) among adolescents, it is still understudied in adolescents attending vocational schools: an educational setting generally associated with lower socioeconomic status. After extending the “Saving and Empowering Young Lives in Europe” (SEYLE) project to a vocational school population, we examined their D-SIB and life event characteristics compared to the high school population. SEYLE’s Hungarian randomly selected high school sample (N = 995) was completed with a randomly selected vocational school sample (N = 140) in Budapest, Hungary. Participants aged 14–17 years completed the SEYLE project’s self-administered questionnaires. D-SIB lifetime prevalence was significantly higher (29.4%) in the vocational school group compared to the high school group (17.2%) (Χ2(1) = 12.231, p< 0.001). D-SIB was associated with suicidal ideation in the vocational school group. Different life events were more frequent in the high school than in the vocational school group, and associations between D-SIB and life events differed in the vocational school group compared to the high school group. In conclusion, vocational school students are a vulnerable population with a higher prevalence of D-SIB compared to high school students. Life events and their association with D-SIB also differ in vocational school students compared to high school students. Taking all these into account might contribute to prevention/intervention designed for this population.

less favorable attitudes towards school and classmates and report more bullying [30]. However, so far, adolescents who attend vocational education, at least in Hungary, have remained absent in research regarding D-SIB.
In the "Saving and Empowering Young Lives in Europe" (SEYLE) study-which was funded by the European Union under the Seventh Framework Health Program-more than 12,000 European high school students were assessed from 179 randomly selected high schools within 11 countries: Austria, Estonia, France, Germany, Hungary, Ireland, Israel, Italy, Romania, Slovenia, and Spain. Sweden served as the coordinating center. One of the main aims of the SEYLE project was to collect baseline and follow-up data on health, well-being, and risk-behaviors, including D-SIB among European adolescents, thus compiling an epidemiological database [32].
By extending the SEYLE study, the primary aim of our study was to describe the vocational school population, compared to the high school population-in terms of D-SIB and life events (i.e., whether vocational school students experience more life events than high school students). Our secondary aim was to explore how D-SIB is associated with suicidal ideation in the vocational school group. Another aim of our study was to explore possible differences in the associations between life events and D-SIB. Our final aim was to screen vocational school students with acute suicidal risk (emergency cases) and to offer immediate help for those in need by referring them to specialized care services.
Our hypotheses were as follows: Hypothesis 1. The lifetime prevalence of D-SIB is higher in the vocational school group than in the high school group.

Hypothesis 2.
The prevalence of life events six months prior to assessment is higher in the vocational school group than in the high school group.
Hypothesis 3. D-SIB is associated with suicidal ideation in the vocational school group.

Materials and Methods
In our data collection protocol, we followed the methodology of the SEYLE project [32,33]. The SEYLE study was a Randomized Control Trial (RCT), which was registered at the German Clinical Trials Register (DRKS00000214). Approval for this study was obtained from the Ethical Committee of the Ministry of Human Capacities in Hungary (protocol number: 24798/2013/EKU).
The full description of the methodology, including assessment, instruments, and intervention was previously published [6,32,33].

Participants and Data Collection
Inclusion criteria were students ages 13-18 attending secondary schools in Budapest, Hungary. Two school types: high school and vocational school were included. Schools from both school types were randomly selected. In this current study, the high school group includes the baseline Hungarian population of the SEYLE Study, which was collected from September 2009 to February 2010 [32]. Using the same survey instrument as used in the SEYLE Study, data from the vocational school group was collected in October and November 2013.
Parents and students received both oral and written information about the study protocol and were asked to give written informed consent. Students completed the self-report questionnaires (see below) within the confines of the classroom in the presence of research staff, providing the opportunity to ask questions if necessary.
For emergency cases (participants with acute suicide risk) we followed the methodology of the SEYLE project: students who were categorized as high risk for suicidal behavior according to cut-off criteria of the SEYLE project [32] were referred to specialized care services.

Measurements
Lifetime prevalence of D-SIB was measured with the modified version of the Deliberate Self Harm Inventory [34]. This 6-item version is based on the 9-item DSHI questionnaire by Bjärehed and Lundh [35], a shortened version of the 16 item DSHI that originated from the 17 item DSHI by Gratz [34]. The 6-item version comprises the same facets on frequency, severity, and duration of D-SIB; but D-SIB acts were combined and reduced to assess self-injurious behaviors to the body surface only [6,34]. The questionnaire measures lifetime prevalence for intentional self-cutting, -burning, -hitting, -scratching, -carving and -biting, as well as preventing wounds from healing and skin damage by other methods on a 4-point Likert scale (never, 1-2 times, 3-4 times, 5 or more times). Cronbach-alfa was 0.662 in the vocational school sample and 0.754 in the Hungarian high school sample.
Suicidal ideation (suicidal thoughts or plans) in the last two weeks were assessed with the 4-item Paykel Suicide Scale (PSS) [36]. Each item was rated from 0 (Never) to 5 (Always). The total score was obtained by summing the four items. A fifth question screened the frequency of suicide attempts during the past two weeks, where the pupils could give "yes" or "no" answers. If pupils responded "sometimes", "often", "very often" or "always" to the question: "During the past two weeks, have you reached the point where you seriously considered taking your life or perhaps made plans how you would go about doing it?"; and/or "Yes" to the question "Have you tried to take your own life during the past 2 weeks?" they were identified as emergency cases and immediately referred to a child psychiatrist for further evaluation.
The life events list was developed for the SEYLE study [24,32], based on former life events literature, mainly the Social Readjustment Rating Scale (SRRS) [37]; the Life Events Checklist (LEC) [38]; and the ALCES [39]. The list consists of 27 minor and major life events, from which participants indicate the ones they had experienced during the six months prior to assessment. Indication of other life events at the "other life event" option at the end of the list was also possible.

Statistical Analysis
All statistical analyses were performed using IBM SPSS Statistics 20.0 (IBM Corp. in Armonk, NY, USA). During the selection of statistical tests, it was considered that D-SIB values did not exhibit normal distribution [40].
Descriptive statistics are reported in the text. T-tests were applied for continuous variables and Chi-square test for categorical variables when examining group differences between the vocational school and high school groups.
All tests of hypotheses were considered statistically significant if the two-sided p-value was less than 0.05. Bonferroni correction was applied to control for multiple comparisons.
For D-SIB prevalence, a dichotomized variable was created based on the first five items of the D-SIB questionnaire (assessing D-SIB methods, but not medical treatment due to D-SIB) to determine D-SIB occurrence/absence. For assessment of gender differences in relation to D-SIB methods, D-SIB methods were classified as "cutting type"/"non-cutting type". The cutting type consisted of behaviors of the first and third item of the D-SIB questionnaire (i.e., "ever intentionally cut wrist, arms, or other area(s) of body, or stuck sharp objects into skin such as needles, pins, staples" + "ever intentionally carved words, pictures, designs or other markings into skin, or scratched yourself to the extent that scarring, or bleeding occurred"), while other forms of D-SIB were classified as the non-cutting type.
Binary logistic regression was used to estimate the probability of D-SIB based on life events both in vocational school and in high school groups. Dependent variable was D-SIB occurrence. For this statistical testing, as a second step the 27 life events were categorized in 9 major categories, based on previous literature [22]: problems with or in the family; death of someone; trouble with police or law; problems with schoolwork; personal health problems; difficulties with romantic/sexual relationships; difficulties with friends and pregnancy.

Sample
The vocational school sample consisted of 140 students. Forty percent were female, aged between 14 and 17, and the mean age was 15.21 ± 0.77 years (1 person did not indicate their age). In the high school group, 1009 students participated; 58.9% were female, aged 13-18 years, and the mean age was 15.01 ± 0.8 years.
For a matched sample, we have left out cases under and above the age range 14-17 from the high school sample (14 cases). This resulted in a sample of 995 participants in the high school group, with mean age 15.09 ± 0.75 years, 59.2% were female. Weighting for age and gender) were applied in this sample to match it with the vocational school sample.
To make sure that the weighting process was efficient, we conducted a comparability analysis. Before dropping the 14 cases under and above the age range 14-17, the two groups significantly differed both in age (t = −2.046; df = 1146; p < 0.041) and gender (t = −4.251; df = 1147; p < 0.001). After dropping the 14 cases, difference in age was not statistically significant anymore (t = 1.78; df = 1132; p = 0.075), and in gender we still observed a difference (t = 4.325; df = 1133; p < 0.001). After the weighting procedure, none of the variables differed between the two groups (t = 0.000; df = 1132; p = 1.0 for age; t = 0.065; df = 1133; p = 0.948 for gender).
In the high school population, 11 pupils (1.1%) were considered emergency cases, while 2 (1.4%) pupils in the vocational school population were considered emergency cases.

Gender Differences among Vocational School Students
Examining all types of D-SIB among vocational school students, 25.64% of boys (N = 78) and 35.41% of girls (N = 48) engaged in some form of D-SIB during their lifetime. There were no significant differences in D-SIB lifetime prevalence between girls and boys (X 2 (1) = 1.37; p = 0.242).
The most common method of D-SIB was "cutting-type" methods, which we examined by merging two items of the D-SIB scale. 88.2% of girls and 60% of boys reported this form of D-SIB; this difference is still not significant (X 2 (1) = 3.71; p = 0.054). Distribution of D-SIB methods types by gender can be seen in Table 1.

D-SIB and Suicidality in Vocational School Students
Among vocational school students, 123 participants completed both PSS and D-SIB questions, and 36 of them reported having ever engaged in D-SIB. Mean scores were M = 2.36; SD = 3.6 among those who had, and M = 0.44; SD = 1.08 among those who had not engaged in any form of D-SIB, which is a significant difference between the two groups (t = 4.54; df = 121; p < 0.01).

D-SIB and Suicidality in Vocational School Students
Among vocational school students, 123 participants completed both PSS and D-SIB questions, and 36 of them reported having ever engaged in D-SIB. Mean scores were M = 2.36; SD = 3.6 among those who had, and M = 0.44; SD = 1.08 among those who had not engaged in any form of D-SIB, which is a significant difference between the two groups (t = 4.54; df = 121; p < 0.01).

Life Events in Vocational and High School Students
The following life events differed significantly in frequency of occurrence in the vocational school and high school groups: increased workload at school; appearing for an exam, interview; new family member; divorce between parents; death of a close friend and change of school.
Increased workload at school and appearing for an exam or interview were more frequent in the high school group. New family member; divorce between parents; death of a close friend and change of school were more frequent in the vocational school group.
Frequencies of occurrence of life events in the two groups and results of the Chi-tests are presented in Table 2.

Life Events in Vocational and High School Students
The following life events differed significantly in frequency of occurrence in the vocational school and high school groups: increased workload at school; appearing for an exam, interview; new family member; divorce between parents; death of a close friend and change of school.
Increased workload at school and appearing for an exam or interview were more frequent in the high school group. New family member; divorce between parents; death of a close friend and change of school were more frequent in the vocational school group.
Frequencies of occurrence of life events in the two groups and results of the Chi-tests are presented in Table 2.

D-SIB and Life Events in Vocational and High School Students
As presented in Table 3, in the high school group (N = 995) when testing for associations between D-SIB and individual life events, D-SIB was significantly associated with trouble with parents and breakup with boyfriend/girlfriend (Cox and Snell R 2 = 0.054; Nagelkerke R 2 = 0.087; Omnibus test of model coefficients: X 2 = 41.413, df = 26, p = 0.028; Hosmer and Lemeshow test: X 2 = 8.443, df = 8, p = 0.391).
As presented in Table 4, among life events categories problems with or in the family; trouble with police or law and difficulties with romantic/sexual relationships were associated with D-SIB (Cox and Snell R 2 = 0.058; Nagelkerke R 2 = 0.094; Omnibus test of model coefficients: X 2 = 45,575, df = 1; p < 0.001; Hosmer and Lemeshow test: X 2 = 4,053, df = 7, p = 0.774).

Discussion
To our knowledge, this is the first study to assess the characteristics-i.e., prevalence, gender differences, and associations with suicidal ideation-of D-SIB among vocational school students and to compare them with the characteristics of a sample of high school students. To our knowledge, our study is also the first to compare occurrence of life events in the two school types.
An alarming result of the current study is that almost one-third (29.4%) of the adolescents in the vocational school group reported that they had engaged in some form of D-SIB at some point in their life. This rate is not only significantly higher than the rate of adolescents in the Hungarian high school group who reported that they had engaged in some form of D-SIB at some point of their life, but it is also a remarkably high result compared to high school samples from European countries reported on the SEYLE Study. While the D-SIB prevalence rate of Hungarian high school students was the lowest reported among the participating SEYLE countries, the 29.4% reported by vocational school students in the current study can be considered high (SEYLE Study mean rate was 27.6%, with 17.1% being the lowest and 38.6% being the highest) [6].
Among vocational school students, 25.64% of boys and 35.41% of girls reported a lifetime history of some form of D-SIB. The difference of prevalence between boys and girls was not significant, either when assessing all methods, nor when assessing the most frequent cutting-type of D-SIB, which is usually associated with the female gender [41]. Thus, our results support no gender differences in the prevalence of D-SIB in the general population [3].
The current study identified a high prevalence of suicidal ideation among those students in the vocational school sample who had a reported history of D-SIB. These findings are consistent with previous studies which found associations with suicidality and D-SIB among high-risk youth [42], as well as results on possible functions (e.g., emotion-regulation, self-punishment, and anti-suicidal functions) of D-SIB [43].
Students in the two school types also differed in frequencies of certain life events. While adolescents in the high school group were more likely to report increased workload at school and appearing for an exam/interview in the six months prior to assessment, vocational school students were more likely to report having a new family member, change of school, divorce of parents and death of a close friend. Although some of these events occurred relatively infrequently in both groups, these results on the numbers and severity of life events support findings from studies that identified vocational school students as a group with increased vulnerability regarding several bio-psycho-social conditions [30,31].
According to our findings, it is not only the differences in quantity and quality of life events among vocational school students that contribute to differences in D-SIB prevalence between the two school types. Our results also show that association between life events and D-SIB differ in the two groups: in the high school group, D-SIB was associated with family problems with or in the family; trouble with police or law and difficulties with romantic/sexual relationships, while in the vocational school group, none of the life event categories were associated with D-SIB. Initially, this result might seem surprising, however taking the increased frequency of severe life events and the overall vulnerability to various bio-psycho-social risk factors in this group into account, these results suggest more complex patterns of risk factors in this population. Our results suggest that life events might be associated with D-SIB in various ways in groups with different socioeconomic backgrounds-without discarding the idea that personal experiences behind the same life event labels (e.g., new family member, change in health) can be very different in these populations. Targeted prevention and intervention might benefit from supporting adolescents and their environment (e.g., peers, potential gatekeepers) in coping with these issues. On a broader level, raising awareness among professionals (e.g., in-school and health care) about the differences in the challenging life events students might face can also contribute to increased effectiveness for prevention programs.
Our results need to be interpreted with the consideration of several limitations. The cross-sectional nature of our data does not provide information about causality, and thus longitudinal assessment of this population would be useful future research. Additional limitations are the use of only dichotomous variables that reduce the variability in the model, and using small sample size compared to the number of explanatory variables in the vocational school group. Furthermore, differences in SES between vocational and high school groups were not directly measured. However, we used randomly selected high schools and vocational schools, and as we have highlighted previously, former studies have shown that in Hungary, the SES of students' families is related to the education type attended by their children [30]. A further potential limitation is that students who might be at the highest risk were more likely to be missed during recruitment of participants since consent also depended on adults (school staff and parents) with various levels of involvement and various attitudes towards mental health prevention. This lack of inclusion was also due to school absence and the dropout rates associated with the higher risk level in this population. Thus, real effect sizes might be deflated compared to the ones estimated in this study. Possible biases due to the methods of self-administered questionnaires in a classroom setting, despite research staff's efforts to minimize these effects, should also be considered.
Despite these limitations, our study has several strengths. Vocational school students often stay hidden not only from the attention of researchers, but also from prevention and intervention programs. Thus, raising awareness of self-injury and related psychological and social problems in vocational schools, as well as screening and referring students who might need immediate help to specialized care services, was an important aim and actual outcome of our study. Importantly, our results can contribute to an increased effectiveness of targeted prevention and intervention programs for this population.

Conclusions
Vocational school students are a vulnerable group with high rates of D-SIB in both genders. These prevalences are higher than those reported by high school groups in the SEYLE study on an international level [6]. Vocational school students who engage in D-SIB also report increased rates of symptoms of suicidal ideation. Different life events are more frequent among high school than among vocational school students, and associations between D-SIB and life events might also differ in the two populations. These results indicate an urgent need for prevention and intervention programs for vocational school students. Taking school-type-specific patterns of psychosocial challenges into consideration when designing these programs might contribute to an increased effectiveness of targeted prevention and intervention.
Author Contributions: Danuta Wasserman, Vladimir Carli, Marco Sarchiapone, Camilla Wasserman, Christina W. Hoven and Judit Balazs designed the study and wrote the protocol. Lili O. Horvath participated in the study coordination, was responsible for the data entry and data collection, made the analyses and wrote the first draft of the manuscript. Maria Balint, Luca Farkas, Agnes Kereszteny, Gergely Meszaros, Dora Szentivanyi participated in the study coordination, data collection and data entry. Dora Gyori participated in data analyses. Gyongyver Ferenczi-Dallos took care of the emergency cases and the data collection. Julia Gadoros was the consultant of the project. Szabina Velo participated in the data collection and data entry. All authors contributed to and have approved the final manuscript.