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Risk factors for violence and violence-related injuries among 14- to 18-year-old Finns
Journal of Adolescent Health 38 (2006) 617– 620
Adolescent health brief
Risk factors for violence and violence-related injuries among 14- to 18-year-old Finns Ville M. Mattila, M.D.a,*, Jari P. Parkkari, Ph.D.b, and Arja H. Rimpelä, Ph.D.a a School of Public Health, University of Tampere, Tampere, Finland Tampere Research Center of Sports Medicine, UKK Institute, Tampere, Finland Manuscript received September 20, 2004; manuscript accepted March 14, 2005
b
Abstract
A random sample of 14- to 18-year-old Finns (3319 boys, 3890 girls) were sent a questionnaire on the occurrence of violence and violence-related injury. Altogether, 76% responded. Weekly stress symptoms, depressive mood, smoking, drunkenness, peer drug use, previous unintentional injury, and not living with both parents predicted both incidents. © 2006 Society for Adolescent Medicine. All rights reserved.
Adolescent violence has received increasing attention as a major public health problem during the last decade [1]. Although studies from the United States have shown that violence is related to sociodemographic and behavioral factors [2], little is known thus far about the risk factors of violence-related injuries outside the United States [3,4]. In Finland, the violence-related death rate of adolescents is considerably higher than elsewhere in northern Europe [5]. The purpose of this study was to investigate the risk factors of violence and violence-related injury among 14- to 18year-old adolescents in Finland. Methods Adolescent Health and Lifestyle Survey (AHLS) is a 27-year-old national surveillance system of adolescent health and health-related lifestyle. In February 1999, a 12page structured questionnaire including questions about violence, violence-related injury, sociodemographic background, health, and health behavior was mailed to all adolescents (n ⫽ 9759) born on certain days in June, July, and August in 1980, 1982, and 1984, the average age of the respondents being 14.6, 16.6, and 18.6 years for the respective years. The response rate was 76%.
*Address correspondence to: Dr. Ville Mattila, Stenbäckinkatu 1 A 8, 00250 Helsinki, Finland. E-mail address: [email protected]
Measurement of violence The main question used to investigate the occurrence of violence was, “Have you, during the past month, been in a fight or the subject of violent actions?” In the logistic regression, our first dependent variable (violence yes/no during past month) was based on this question. Those answering “yes” were also asked whether the violence had caused any physical injury. This was our second dependent variable (yes/no violence-related injury). Risk factors Sociodemographic background was described as the father’s or other guardian’s education and occupation, the father’s and mother’s employment status, family composition, urbanization level of the place of residence, and geographic area. Health status was determined from the responses to questions about perceived health, chronic disease, injury or disability that restricted daily activities, eight stress symptoms perceived weekly (stomachache, nervousness, irritability, difficulty sleeping, headache, trembling hands, tiredness, dizziness), for which a summary index was formed, body mass index, and depressive mood (feeling blue or hopeless, and uninterested). Information on unintentional injury was elicited by asking whether the adolescent had had an injury that needed attention by doctor or nurse during the past month. Information on health behavior was elicited in questions
1054-139X/06/$ – see front matter © 2006 Society for Adolescent Medicine. All rights reserved. doi:10.1016/j.jadohealth.2005.03.007
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V.M. Mattila et al. / Journal of Adolescent Health 38 (2006) 617– 620
on the use of tobacco, snuff, and alcohol, and the regularity of tooth brushing, physical activity, sleeping hours, and peer drug use. Statistical methods Forward stepwise logistic regression was applied to study the association between violence and violence-related injury and the categorical explanatory variables. Age and gender were included in the models. The odds ratios and 95% confidence intervals were calculated. Analyses were carried out for each category of variables separately (sociodemographic background, health, health behavior). The frequency of missing values in the models varied between 3% and 14%. Results Altogether, 337 (10.2%) of the boys and 234 (6.0%) of the girls reported violence. The corresponding numbers for violence-related injury were 52 (1.6%) and 72 (1.9%), respectively. Violence decreased with age, being 8.8% for the 14-year-olds and 6.1% for the 18-year-olds (p ⬍ .001). Age was not significantly related to violence-related injury. About 22% of the adolescents who reported violence had been injured. Family composition was a significant risk factor for
violence and related injury, whereas the father’s or other guardian’s education was related only to violence (Table 1). Recent unintentional injury and several stress symptoms weekly emerged as the strongest risk factors for violence and violence-related injury (Table 1). The adolescents who reported peer drug use had a greater risk for violence and related injury, as did the adolescents who reported frequent smoking and frequent drinking (Table 2). Discussion Our findings support the results of prior studies that showed sociodemographic background, health, and health behavior to be associated with violent behavior [6]. Moreover, the main finding of our study indicated that the risk factors for violence and violence-related injury are similar. To our knowledge, this study provides the first nationwide survey of the risk factors of adolescent violence and violence-related injury in Europe. According to earlier studies, the reliability of the background variables in our study (sociodemographic background, smoking, and weekly stress symptoms) was good [7]. The finding of a greater risk of violence and violencerelated injury among adolescents not living with both parents is in agreement with results presented earlier in the
Table 1 Violence and violence-related injuries by significant sociodemographic background and health variables Risk factor
Sociodemographic background Family composition Father’s education
Health Number of psychosomatic symptoms perceived at least once a week
Self-perceived health
Depressive mood during last month Unintentional injury occurrence during past month
Category
Violence
Violence-related injury
Frequency (%)
OR (95% CI)
Frequency (%)
OR (95% CI)
Both own parents Other High Middle Low
6.9 10.9 6.0 5.8 8.8
1 1.7 (1.4–2.1) 1 .9 (.6–1.3) 1.4 (1.1–1.8)
1.3 2.8 1.2 .6 2.1
1 2.0 (1.4–3.2) NS
0 1 2 3⫹ Excellent Quite good Average or worse
4.2 5.9 7.8 13.0 6.2 7.2 12.4
1 1.4 (1.0–1.9) 2.0 (1.4–2.7) 3.2 (2.5–4.2) 1 1.0 (.9–1.4) 1.5 (1.2–2.0)
.6 1.1 1.2 3.4 1.2 1.4 3.3
1 1.8 (.9–3.9) 1.6 (.7–3.7) 4.3 (2.3–8.0) NS
No Yes
5.4 14.0
1 1.6 (1.3–2.0)
.8 3.7
1 1.8 (1.2–2.7)
No Yes
6.7 25.1
1 4.0 (3.1–5.2)
1.2 9.9
1 8.0 (5.3–12.0)
Odds ratios (OR) adjusted for age and gender in the forward stepwise logistic regression model.
V.M. Mattila et al. / Journal of Adolescent Health 38 (2006) 617– 620
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Table 2 Violence and violence-related injuries by significant health behavior Risk factor
Health behavior Snuffing
Smoking
Drinking style
Peer drug use Participation in sports in a sports club
Category
Never tried Tried More than 50 times Never tried Not daily or tried only Less than 10 cigarettes daily More than 10 cigarettes daily Abstinence Occasional drinking Frequent drinking Frequent drunkenness No Yes Never Once a week or less 2–5 times a week Approximately every day
Violence
Violence-related Injury
Frequency (%)
OR (95% CI)
Frequency (%)
OR (95% CI)
5.9 14.3 22.3 3.9 5.9 12.1 19.1 3.6 4.8 6.3 16.0 4.6 11.5
1 1.2 (1.0–1.6) 1.9 (1.3–2.9) 1 1.4 (.9–1.9) 2.4 (1.5–3.6) 3.2 (2.1–4.9) 1 1.3 (.8–2.0) 1.5 (1.0–2.3) 2.9 (1.9–4.5) 1 2.0 (1.6–2.5)
1.2 3.3 5.6 .7 1.4 2.5 4.2 .6 1.1 1.3 3.6 .7 2.8
NS
6.7 9.9 8.5 8.6
1 1.6 (1.2–2.0) 1.3 (1.0–1.6) 1.2 (.8–1.9)
1.6 1.5 1.7 2.5
1 1.5 (.7–3.2) 1.8 (.8–4.4) 2.9 (1.3–6.5) 1 1.1 (.5–2.8) 1.2 (.5–3.0) 2.4 (1.0–5.8) 1 2.6 (1.6–4.2) NS
Odds ratios (OR) adjusted for age and gender in the forward stepwise logistic regression model.
literature [8]. A lower level of education of the father seemed to increase an adolescent’s risk for violence. It is evident that a lower sociodemographic background predicts violence and violence-related injury in Finland, although to a lesser extent than in the United States [9]. Possible explanations for the difference are a more homogeneous structure of society and less variation in income in Finland than in the United States. The number of stress symptoms weekly, poor perceived health, and depressive mood were significant risk factors for violence and violence-related injury. The association between violence, violence-related injury, and a previous unintentional injury was strong. Our study is limited by the fact that cross-sectional data cannot show causality, and thus the causality of these risk factors must remain as a challenge for future research. In addition, our findings were based on self-reports, and our violence variable encompassed both perpetration and victimization. Drunkenness greatly increased the risk of violence and violence-related injury in our study, confirming the findings of previous studies. It has been shown that alcohol abuse or misuse is a very important risk factor of different types of violence and injury among adolescents [10]. In addition, smoking and peer drug use were also strong risk factors for violence and violence-related injury in our study; this finding suggests that many Finnish adolescents engage in a lifestyle that includes several types of health risk behavior. Although the effect of sociodemographic background on violence and violence-related injury was weaker in Finland than in the United States, several risk factors were similar. It is evident that peer drug use, smoking, and drinking are
risk factors for violence and injury across countries and cultures. These findings are important when plans are made to promote adolescent health because, in addition to health and health behavior, violence and violence-related injury should be taken into consideration. Moreover, the role of school-based prevention should be addressed, as such prevention may reach Finnish adolescents better than attempts made by the health care system. The strong association found between violence-related and unintentional injury requires additional research.
Acknowledgments The study was supported by the Ministry of Social Affairs and Health, the Medical Research Fund of Tampere University Hospital, Tampere, Finland, the Yrjö Jahnsson Foundation and the Finnish Cultural Foundation. We thank Ville Autio and Lasse Pere from the University of Tampere for their statistical advice and Marja Vajaranta from the University of Tampere for her language editing.
Reference [1] Krug EG, Dahlberg LL, Mercy JA. World Report on Violence and Health. Geneva, Switzerland: World Health Organization, 2002: 1–372. [2] Swahn M, Donovan J. Correlates and predictors of violent behavior among adolescent drinkers. J Adolesc Health 2004;34:480 –92.
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V.M. Mattila et al. / Journal of Adolescent Health 38 (2006) 617– 620
[3] Arseneault L, Moffitt TE, Caspi A, et al. Mental disorders and violence in a total birth cohort: results from the Dunedin Study. Arch Gen Psychiatry 2000;57:979 – 86. [4] Kemppainen L, Jokelainen J, Jarvelin MR, et al. The one-child family and violent criminality: a 31-year follow-up study of the Northern Finland 1966 Birth Cohort. Am J Psychiatry 2001;158: 960 –2. [5] Lehti M. Henkirikoskatsaus. Helsinki, Finland: Oikeuspoliittinen tutkimuslaitos, 2004:143. [6] Herrenkohl TI, Maguin E, Hill KG, et al. Developmental risk factors for youth violence. J Adolesc Health 2000;26:176 – 86.
[7] Koivusilta LK, Rimpela AH, Rimpela M, et al. Health behavior-based selection into educational tracks starts in early adolescence. Health Educ Res 2001;16:201–14. [8] Diaz A, Simantov E, Rickert VI. Effect of abuse on health: results of a national survey. Arch Pediatr Adolesc Med 2002;156:811–7. [9] Blum RW, Beuhring T, Shew ML, et al. The effects of race/ethnicity, income, and family structure on adolescent risk behaviors. Am J Public Health 2000;90:1879 – 84. [10] Durant RH, Altman D, Wolfson M, et al. Exposure to violence and victimization, depression, substance use, and the use of violence by young adolescents. J Pediatr 2000;137:707–13.
Adolescent health brief
Risk factors for violence and violence-related injuries among 14- to 18-year-old Finns Ville M. Mattila, M.D.a,*, Jari P. Parkkari, Ph.D.b, and Arja H. Rimpelä, Ph.D.a a School of Public Health, University of Tampere, Tampere, Finland Tampere Research Center of Sports Medicine, UKK Institute, Tampere, Finland Manuscript received September 20, 2004; manuscript accepted March 14, 2005
b
Abstract
A random sample of 14- to 18-year-old Finns (3319 boys, 3890 girls) were sent a questionnaire on the occurrence of violence and violence-related injury. Altogether, 76% responded. Weekly stress symptoms, depressive mood, smoking, drunkenness, peer drug use, previous unintentional injury, and not living with both parents predicted both incidents. © 2006 Society for Adolescent Medicine. All rights reserved.
Adolescent violence has received increasing attention as a major public health problem during the last decade [1]. Although studies from the United States have shown that violence is related to sociodemographic and behavioral factors [2], little is known thus far about the risk factors of violence-related injuries outside the United States [3,4]. In Finland, the violence-related death rate of adolescents is considerably higher than elsewhere in northern Europe [5]. The purpose of this study was to investigate the risk factors of violence and violence-related injury among 14- to 18year-old adolescents in Finland. Methods Adolescent Health and Lifestyle Survey (AHLS) is a 27-year-old national surveillance system of adolescent health and health-related lifestyle. In February 1999, a 12page structured questionnaire including questions about violence, violence-related injury, sociodemographic background, health, and health behavior was mailed to all adolescents (n ⫽ 9759) born on certain days in June, July, and August in 1980, 1982, and 1984, the average age of the respondents being 14.6, 16.6, and 18.6 years for the respective years. The response rate was 76%.
*Address correspondence to: Dr. Ville Mattila, Stenbäckinkatu 1 A 8, 00250 Helsinki, Finland. E-mail address: [email protected]
Measurement of violence The main question used to investigate the occurrence of violence was, “Have you, during the past month, been in a fight or the subject of violent actions?” In the logistic regression, our first dependent variable (violence yes/no during past month) was based on this question. Those answering “yes” were also asked whether the violence had caused any physical injury. This was our second dependent variable (yes/no violence-related injury). Risk factors Sociodemographic background was described as the father’s or other guardian’s education and occupation, the father’s and mother’s employment status, family composition, urbanization level of the place of residence, and geographic area. Health status was determined from the responses to questions about perceived health, chronic disease, injury or disability that restricted daily activities, eight stress symptoms perceived weekly (stomachache, nervousness, irritability, difficulty sleeping, headache, trembling hands, tiredness, dizziness), for which a summary index was formed, body mass index, and depressive mood (feeling blue or hopeless, and uninterested). Information on unintentional injury was elicited by asking whether the adolescent had had an injury that needed attention by doctor or nurse during the past month. Information on health behavior was elicited in questions
1054-139X/06/$ – see front matter © 2006 Society for Adolescent Medicine. All rights reserved. doi:10.1016/j.jadohealth.2005.03.007
618
V.M. Mattila et al. / Journal of Adolescent Health 38 (2006) 617– 620
on the use of tobacco, snuff, and alcohol, and the regularity of tooth brushing, physical activity, sleeping hours, and peer drug use. Statistical methods Forward stepwise logistic regression was applied to study the association between violence and violence-related injury and the categorical explanatory variables. Age and gender were included in the models. The odds ratios and 95% confidence intervals were calculated. Analyses were carried out for each category of variables separately (sociodemographic background, health, health behavior). The frequency of missing values in the models varied between 3% and 14%. Results Altogether, 337 (10.2%) of the boys and 234 (6.0%) of the girls reported violence. The corresponding numbers for violence-related injury were 52 (1.6%) and 72 (1.9%), respectively. Violence decreased with age, being 8.8% for the 14-year-olds and 6.1% for the 18-year-olds (p ⬍ .001). Age was not significantly related to violence-related injury. About 22% of the adolescents who reported violence had been injured. Family composition was a significant risk factor for
violence and related injury, whereas the father’s or other guardian’s education was related only to violence (Table 1). Recent unintentional injury and several stress symptoms weekly emerged as the strongest risk factors for violence and violence-related injury (Table 1). The adolescents who reported peer drug use had a greater risk for violence and related injury, as did the adolescents who reported frequent smoking and frequent drinking (Table 2). Discussion Our findings support the results of prior studies that showed sociodemographic background, health, and health behavior to be associated with violent behavior [6]. Moreover, the main finding of our study indicated that the risk factors for violence and violence-related injury are similar. To our knowledge, this study provides the first nationwide survey of the risk factors of adolescent violence and violence-related injury in Europe. According to earlier studies, the reliability of the background variables in our study (sociodemographic background, smoking, and weekly stress symptoms) was good [7]. The finding of a greater risk of violence and violencerelated injury among adolescents not living with both parents is in agreement with results presented earlier in the
Table 1 Violence and violence-related injuries by significant sociodemographic background and health variables Risk factor
Sociodemographic background Family composition Father’s education
Health Number of psychosomatic symptoms perceived at least once a week
Self-perceived health
Depressive mood during last month Unintentional injury occurrence during past month
Category
Violence
Violence-related injury
Frequency (%)
OR (95% CI)
Frequency (%)
OR (95% CI)
Both own parents Other High Middle Low
6.9 10.9 6.0 5.8 8.8
1 1.7 (1.4–2.1) 1 .9 (.6–1.3) 1.4 (1.1–1.8)
1.3 2.8 1.2 .6 2.1
1 2.0 (1.4–3.2) NS
0 1 2 3⫹ Excellent Quite good Average or worse
4.2 5.9 7.8 13.0 6.2 7.2 12.4
1 1.4 (1.0–1.9) 2.0 (1.4–2.7) 3.2 (2.5–4.2) 1 1.0 (.9–1.4) 1.5 (1.2–2.0)
.6 1.1 1.2 3.4 1.2 1.4 3.3
1 1.8 (.9–3.9) 1.6 (.7–3.7) 4.3 (2.3–8.0) NS
No Yes
5.4 14.0
1 1.6 (1.3–2.0)
.8 3.7
1 1.8 (1.2–2.7)
No Yes
6.7 25.1
1 4.0 (3.1–5.2)
1.2 9.9
1 8.0 (5.3–12.0)
Odds ratios (OR) adjusted for age and gender in the forward stepwise logistic regression model.
V.M. Mattila et al. / Journal of Adolescent Health 38 (2006) 617– 620
619
Table 2 Violence and violence-related injuries by significant health behavior Risk factor
Health behavior Snuffing
Smoking
Drinking style
Peer drug use Participation in sports in a sports club
Category
Never tried Tried More than 50 times Never tried Not daily or tried only Less than 10 cigarettes daily More than 10 cigarettes daily Abstinence Occasional drinking Frequent drinking Frequent drunkenness No Yes Never Once a week or less 2–5 times a week Approximately every day
Violence
Violence-related Injury
Frequency (%)
OR (95% CI)
Frequency (%)
OR (95% CI)
5.9 14.3 22.3 3.9 5.9 12.1 19.1 3.6 4.8 6.3 16.0 4.6 11.5
1 1.2 (1.0–1.6) 1.9 (1.3–2.9) 1 1.4 (.9–1.9) 2.4 (1.5–3.6) 3.2 (2.1–4.9) 1 1.3 (.8–2.0) 1.5 (1.0–2.3) 2.9 (1.9–4.5) 1 2.0 (1.6–2.5)
1.2 3.3 5.6 .7 1.4 2.5 4.2 .6 1.1 1.3 3.6 .7 2.8
NS
6.7 9.9 8.5 8.6
1 1.6 (1.2–2.0) 1.3 (1.0–1.6) 1.2 (.8–1.9)
1.6 1.5 1.7 2.5
1 1.5 (.7–3.2) 1.8 (.8–4.4) 2.9 (1.3–6.5) 1 1.1 (.5–2.8) 1.2 (.5–3.0) 2.4 (1.0–5.8) 1 2.6 (1.6–4.2) NS
Odds ratios (OR) adjusted for age and gender in the forward stepwise logistic regression model.
literature [8]. A lower level of education of the father seemed to increase an adolescent’s risk for violence. It is evident that a lower sociodemographic background predicts violence and violence-related injury in Finland, although to a lesser extent than in the United States [9]. Possible explanations for the difference are a more homogeneous structure of society and less variation in income in Finland than in the United States. The number of stress symptoms weekly, poor perceived health, and depressive mood were significant risk factors for violence and violence-related injury. The association between violence, violence-related injury, and a previous unintentional injury was strong. Our study is limited by the fact that cross-sectional data cannot show causality, and thus the causality of these risk factors must remain as a challenge for future research. In addition, our findings were based on self-reports, and our violence variable encompassed both perpetration and victimization. Drunkenness greatly increased the risk of violence and violence-related injury in our study, confirming the findings of previous studies. It has been shown that alcohol abuse or misuse is a very important risk factor of different types of violence and injury among adolescents [10]. In addition, smoking and peer drug use were also strong risk factors for violence and violence-related injury in our study; this finding suggests that many Finnish adolescents engage in a lifestyle that includes several types of health risk behavior. Although the effect of sociodemographic background on violence and violence-related injury was weaker in Finland than in the United States, several risk factors were similar. It is evident that peer drug use, smoking, and drinking are
risk factors for violence and injury across countries and cultures. These findings are important when plans are made to promote adolescent health because, in addition to health and health behavior, violence and violence-related injury should be taken into consideration. Moreover, the role of school-based prevention should be addressed, as such prevention may reach Finnish adolescents better than attempts made by the health care system. The strong association found between violence-related and unintentional injury requires additional research.
Acknowledgments The study was supported by the Ministry of Social Affairs and Health, the Medical Research Fund of Tampere University Hospital, Tampere, Finland, the Yrjö Jahnsson Foundation and the Finnish Cultural Foundation. We thank Ville Autio and Lasse Pere from the University of Tampere for their statistical advice and Marja Vajaranta from the University of Tampere for her language editing.
Reference [1] Krug EG, Dahlberg LL, Mercy JA. World Report on Violence and Health. Geneva, Switzerland: World Health Organization, 2002: 1–372. [2] Swahn M, Donovan J. Correlates and predictors of violent behavior among adolescent drinkers. J Adolesc Health 2004;34:480 –92.
620
V.M. Mattila et al. / Journal of Adolescent Health 38 (2006) 617– 620
[3] Arseneault L, Moffitt TE, Caspi A, et al. Mental disorders and violence in a total birth cohort: results from the Dunedin Study. Arch Gen Psychiatry 2000;57:979 – 86. [4] Kemppainen L, Jokelainen J, Jarvelin MR, et al. The one-child family and violent criminality: a 31-year follow-up study of the Northern Finland 1966 Birth Cohort. Am J Psychiatry 2001;158: 960 –2. [5] Lehti M. Henkirikoskatsaus. Helsinki, Finland: Oikeuspoliittinen tutkimuslaitos, 2004:143. [6] Herrenkohl TI, Maguin E, Hill KG, et al. Developmental risk factors for youth violence. J Adolesc Health 2000;26:176 – 86.
[7] Koivusilta LK, Rimpela AH, Rimpela M, et al. Health behavior-based selection into educational tracks starts in early adolescence. Health Educ Res 2001;16:201–14. [8] Diaz A, Simantov E, Rickert VI. Effect of abuse on health: results of a national survey. Arch Pediatr Adolesc Med 2002;156:811–7. [9] Blum RW, Beuhring T, Shew ML, et al. The effects of race/ethnicity, income, and family structure on adolescent risk behaviors. Am J Public Health 2000;90:1879 – 84. [10] Durant RH, Altman D, Wolfson M, et al. Exposure to violence and victimization, depression, substance use, and the use of violence by young adolescents. J Pediatr 2000;137:707–13.