A natural experiment: Assessment of Danish high-school students' alcohol drinking patterns from 2014 and 2019 after the introduction of a common alcohol policy.

AIM: In this study, using national survey data from 2014 and 2019, we tested the hypothesis that students at schools who introduced a common alcohol policy in 2017 drank less than students at schools without a common policy. METHODS: We used survey data from 41 high schools that participated in the Danish National Youth Study in 2014 and 2019. We perceived the introduction of a common high-school alcohol policy in 2017 among local groups of high schools as a natural experiment and assessed it using difference-in-difference analyses. We assessed drinking patterns from 2014 and 2019 among students at schools with and without a common alcohol policy combined and stratified by sex in negative binominal regression and logistic regression models. Drinking patterns were measured as average weekly alcohol use, average alcohol intake at last school party, proportion of non-drinkers and frequent binge drinkers. RESULTS: Drinking patterns were similar among students in schools with and without a common alcohol policy. For example, among students at schools with a common alcohol policy, the average alcohol intake at the last school party among drinkers was 8.7 units in 2014 and 8.5 units in 2019, whereas average alcohol intake among students at schools without a common alcohol policy was 8.8 units in 2014 and 8.9 units in 2019 (p=0.413). CONCLUSIONS: No statistically significant effects were observed following the introduction of a common alcohol policy on students' drinking patterns, and alcohol consumption among high-school students was stable and remained high in 2014 and in 2019.

Does Class Proportion of Students with Non-Western Origin in High Schools Affect Drinking Habits Among Ethnic Danish Students?

AIM: the objective was to test the hypothesis that a higher proportion of students with non-Western origin in high school classes is associated with lower and less frequent alcohol consumption among ethnic Danish students. METHOD: data on country of origin was obtained from the Danish Civil Registration System, while information on drinking habits were derived from the Danish National Youth Study 2014. Multilevel zero-inflated binominal regression was used to assess the association between class proportion of students with non-Western origin and odds of non-drinking and mean weekly alcohol consumption, while multilevel logistic regression was used to assess the association with frequent binge drinking. RESULTS: a higher proportion of students with non-Western origin in class was associated with higher odds of non-drinking among ethnic Danish student in the same class. For example, ethnic Danish boys in classes with more than 15% of the students of non-Western origin had 77% higher odds of being non-drinkers, compared to ethnic Danish boys in classes where 0-5% had non-Western origin (OR: 1.77, 95% CI; 1.42-2.20). Among ethnic Danish students that did consume alcohol, class proportion of students with non-Western origin was not associated with weekly alcohol consumption, while a higher proportion of students with non-Western origin in class was associated with lower odds of frequent binge drinking. CONCLUSION: the downward drinking trend among adolescents in Western countries may be partly explained by the higher proportion of youth with non-Western origin, influencing the prevalence of drinking and frequency of binge drinking among adolescents in the ethnic majority population.

School factors and student drinking in high schools: a cross-sectional study of school policies and party regulation.

BACKGROUND: The effectiveness of school alcohol polices may be affected by the degree of strictness of rules, how they are implemented and enforced, students' perception of the rules and the consequences of breaking them. The aim of the study was to test the hypothesis that more liberal school alcohol policies, lack of knowledge of the alcohol policy, lower prices of alcohol at school parties, and liberal party regulation were associated with more drinking among high school students. METHODS: Participants were high school students (n = 68,898), participating in the Danish National Youth Study in 2014. Data came from questionnaires answered by high school students and school headmasters. Zero-inflated negative binominal regression with clustering of schools (n = 117) was used to assess the associations between alcohol policy reported by school headmaster and weekly alcohol intake reported by students. Multilevel negative binominal regression was used to assess the associations between alcohol price and liberal party regulations and units consumed at the last school party and units consumed at the school during the last school party. RESULTS: In general, school alcohol policies were not associated with high school students' weekly alcohol intake. High school students who did not know the school alcohol policy had a higher weekly alcohol intake (0.16 drinks 95% CL [0.11;0.21] p = 0.000), compared to students who knew the policy. Lower beer prices were positively associated with the number of drinks consumed at the school (p = 0.004), but not with the total amount consumed at the last school party (p = 0.728). High school students who agreed that students who were drunk could buy alcohol had a higher alcohol intake at the last school party (OR = 0.20 drinks 95% CL [0.18;0.21], p < 0.001) and drank more at the school (0.17 drinks 95% CL [0.15;0.18], p < 0.001) compared to those who did not agree that students who were drunk could buy alcohol. CONCLUSION: School alcohol policies were generally not associated with drinking among high school students, whereas students' lack of knowledge of the school policy was associated with a higher weekly alcohol intake. An addition, lower prices and liberal party regulation was associated with higher alcohol intake at school parties.

School- and class-level variation in self-harm, suicide ideation and suicide attempts in Danish high schools.

AIM: Strong associations have been found between being exposed to self-harm in family and friends and own self-harm in adolescence. Therefore, self-harm and suicide behaviour might tend to cluster within school and school classes. The aim of this study was to describe the prevalence, frequency and type of self-harm, suicide ideation and suicide attempts within Danish high schools and to test whether self-harm and suicide behaviour cluster in schools and school classes. METHODS: Data came from the Danish National Youth Study 2014, a national survey. The respective study included 66,284 high-school students nested in 117 schools and 3146 school classes. The prevalence and clustering of self-harm behaviour, ever and within the last year, type of self-harm (e.g. cutting, burning, scratching and hitting) and suicide ideation and suicide attempts were investigated. Multi-level logistic regression was applied to quantify clustering among participants within the same class and school. RESULTS: In total, 12,960 (20%) reported self-harm ever and 5706 (8.6%) within the last year. Prevalence was higher among girls than boys. Among girls, cutting (15%) and scratching (13%) was the most common type of self-harm, whereas among boys, hitting (6.7%) was most prevalent. The degree of clustering of self-harm and suicide behaviour was low, with school-level intra-class correlation coefficients (ICC) ranging from 0.8-1.8% and school class level ICC's from 4.3-6.8%. CONCLUSIONS: This study shows that self-harm was common, especially in girls. The degree of clustering of self-harm and suicide behaviour in school and school classes was low.

Self-injury and suicide behavior among young people with perceived parental alcohol problems in Denmark: a school-based survey.

The aim of this study was to test the hypothesis that young people who perceive their parents to have alcohol problems are more likely to self-injure, have suicide ideation, and to attempt suicide than young people without parental alcohol problems. We also tested whether the association between parental alcohol problems and self-injury, suicide ideation, and suicide attempt among young people differed depending on the gender of the child and the parent. Data came from the Danish National Youth Study 2014, a web-based national survey. A total of 75,853 high school and vocational school students participated. Self-injury, suicidal ideation, and suicide attempts were outcomes and the main exposure variables were perceived parental alcohol problems, gender of the parent with alcohol problems, cohabitation with a parent with alcohol problems, and severity of the parents' alcohol problems. Young people with parental alcohol problems had higher odds of self-injury [boys: OR = 1.59 (95% CI 1.40-1.82); girls: OR = 1.84 (95% CI 1.69-1.99)], suicidal ideation [boys: OR = 1.81 (95% CI 1.59-2.06); girls: OR 1.74 (95% CI 1.59-1.89)], and suicide attempt [boys: OR = 2.10 (95% CI 1.63-2.71); girls: OR = 2.09 (95% CI 1.80-2.42)] compared to young people without parental alcohol problems. Girls with parental alcohol problems had higher odds of self-injury than boys with parental alcohol problems, whereas no gender differences were found for suicidal ideation and suicide attempts. Also no differences were found depending on the gender of the parent with alcohol problems. This study shows that young people with parental alcohol problems have higher odds of self-injury, suicide ideation, and suicide attempts.

Perceived parental alcohol problems and drinking patterns in youth: A cross-sectional study of 69,030 secondary education students in Denmark.

The aim of the study was to examine whether young people with parental alcohol problems have different drinking patterns than those without parental alcohol problems. Further, we examined whether the association between parental alcohol problems and young people's drinking patterns differed depending on the gender of the child and the parent, and whether more severe parental alcohol problems and cohabitation with the parent with alcohol problems was associated with earlier and heavier drinking patterns. Data came from the Danish National Youth Study 2014, a web-based national survey. 75,025 high school and vocational school students (15-25years) participated. Drinking patterns were investigated by the following outcomes: non-drinking, weekly alcohol consumption, frequent binge drinking, and early intoxication debut age. The main predictor variables were perceived parental alcohol problems, gender of the parent with alcohol problems, cohabitation with a parent with alcohol problems and severity of the parents' alcohol problems. Young people with parental alcohol problems had a higher weekly alcohol consumption (boys: 15.2 vs. 13.9 drinks per week; girls: 11.6 vs. 10.2 drinks per week), higher odds of early intoxication debut age (boys: OR=1.68 [95% CI 1.50-1.89]; girls: OR 1.95 [95% CI 1.79-2.14]), and more frequent binge drinking (boys, OR=1.16 [95% CI 1.04-1.29]; girls, OR=1.21 [95% CI 1.11-1.32]) compared to young people without parental alcohol problems. In conclusion, this study shows that young people with perceived parental alcohol problems have an earlier intoxication debut age, binge drink more frequently, and drink larger quantities per week than young people without perceived parental alcohol problems.

Social Disconnectedness, Loneliness, and Mental Health Among Adolescents in Danish High Schools: A Nationwide Cross-Sectional Study.

Background: Previous research has suggested that social disconnectedness experienced at school is linked to mental health problems, however, more research is needed to investigate (1) whether the accumulation of various types of social disconnectedness is associated with risk for mental health problems, and (2) whether loneliness is a mechanism that explains these associations. Methods: Using data from the Danish National Youth Study 2019 (UNG19), nation-wide cross-sectional data from 29,086 high school students in Denmark were analyzed to assess associations between social disconnectedness experienced at school (lack of classmate support, lack of teacher support, lack of class social cohesion, and not being part of the school community) and various mental health outcomes, as well as the mediating role of loneliness for each type of disconnectedness. Multilevel regression analyses were conducted to assess the associations. Results: Descriptive analyses suggest that 27.5% of Danish high school students experience at least one type of social disconnectedness at school. Each type of social disconnectedness was positively associated with mental health problems (depression symptoms, anxiety symptoms, stress, sleep problems, suicidal ideation, non-suicidal self-injury, eating disorder, body dissatisfaction, and low self-esteem) and negatively associated with mental well-being. In all cases, loneliness significantly mediated the associations. We found a clear dose-response pattern, where each addition in types of social disconnectedness was associated with (1) stronger negative coefficients with mental well-being and (2) stronger positive coefficients with mental health problems. Conclusion: Our results add to a large evidence-base suggesting that mental health problems among adolescents may be prevented by promoting social connectedness at school. More specifically, fostering social connectedness at school may prevent loneliness, which in turn may promote mental well-being and prevent mental health problems during the developmental stages of adolescence. It is important to note that focusing on single indicators of school social connectedness/disconnectedness would appear to be insufficient. Implications for practices within school settings to enhance social connectedness are discussed.

Trends in smoking and smokeless tobacco use among Danish Adolescents, 1997-2014.

INTRODUCTION: High rates of smoking among adolescents remain a public health concern. This study investigates smoking behavior and use of smokeless tobacco among Danish high-school students and assesses how smoking and use of smokeless tobacco cluster in schools and school classes. We estimate the trend in cigarette smoking from 1997 to 2014. METHODS: We used data on 70 243 students, from 3 214 school classes in 119 high schools, who participated in the Danish National Youth Study from 2014. We had information on 87% of all Danish high schools and 85% of eligible students. We also used data from 1997 on 26 644 high-school students from a similar data set to assess the chronological trend in smoking. We calculated prevalences and intraclass correlation coefficients (ICCs) to estimate between-school and between-school class clustering in smoking and use of smokeless tobacco. RESULTS: In all, 14% of boys and 11% of girls were daily smokers. A large fraction of the variation in smoking and the use of smokeless tobacco was attributable to the school and school-class level (ICC of 0.19, 0.12, 0.16 and 0.27, for daily smoking, waterpipe smoking, use of electronic cigarettes and snuff/chewing tobacco, respectively). Daily smoking decreased from 15% in 1997 to 12% in 2014, while more students were occasional smokers in 2014 than in 1997 (30% vs 18%). CONCLUSIONS: The prevalence of smoking was high among Danish high-school students and had changed little since 1997. The school and class environment accounted for a large part of the variation in smoking behavior.

Perceived parental alcohol problems, internalizing problems and impaired parent - child relationships among 71 988 young people in Denmark.

AIMS: To test the hypothesis that young people with perceived parental alcohol problems have poorer parent-child relationships and more emotional symptoms, low self-esteem, loneliness and depression than young people without perceived parental alcohol problems. DESIGN: Cross-sectional analysis using data from the Danish National Youth Study 2014, a web-based national survey. SETTING: Denmark. PARTICIPANTS: A total of 71.988 high school and vocational school students (aged 12-25, nested in 119 schools and 3.186 school classes) recruited throughout 2014. MEASUREMENTS: Outcome variables included internalizing problems such as emotional symptoms, depression, self-esteem, loneliness and aspects of the parent-child relationship. The main predictor variable was perceived parental alcohol problems, including the severity of the perceived problems and living with a parent with alcohol problems. Control variables included age, sex, education, ethnicity, parents' separation and economic problems in the family. FINDINGS: Boys and girls with perceived parental alcohol problems had statistically significant higher odds of reporting internalizing problems (e.g. frequent emotional symptoms: odds ratio (OR)= 1.58 for boys; 1.49 for girls) and poor parent-child relationships (e.g. lack of parental interest: OR = 1.92 for boys; 2.33 for girls) compared with young people without perceived parental alcohol problems. The associations were not significantly stronger for mother's alcohol problems or if the young person lived with the parent with perceived alcohol problems. CONCLUSION: Boys and girls in secondary education in Denmark who report perceived parental alcohol problems have significantly higher odds of internalizing problems and poorer parent-child relationships compared with young people without perceived parental alcohol problems.