Preventing Stress among High School Students in Denmark through the Multicomponent Healthy High School Intervention-The Effectiveness at First Follow-Up

Stress is a widespread phenomenon and young people especially are experiencing high levels of stress. School-related factors are the most frequently self-reported stressors among adolescents, but few interventions have targeted the school environment. This study evaluated the effectiveness of the Healthy High School (HHS) intervention on stress at a 9-month follow-up. The study included 5201 first-year high school students (~16 years) in Denmark. Participating schools were randomized into the HHS intervention (N = 15) or control group (N = 15). Baseline measurements were conducted in August 2016 and the follow-up was conducted in May 2017. The intervention was designed to promote well-being (primary outcome) by focusing on physical activity, meals, sleep, sense of security, and stress (secondary outcomes). The intervention comprised: structural initiatives at the school level; a teaching material; peer-led innovation workshops; and a smartphone app. The 10-item Perceived Stress Scale was used to measure stress. Intervention effects on perceived stress were estimated using an intention-to-treat approach with multiple imputations of missing data and multilevel general linear regression modelling. A total of 4577 students answered the baseline questionnaire. No statistically significant difference was found in stress between students at intervention and control schools at the follow-up (mean score: 16.7 versus 16.7, adjusted b = 0.42, 95% CI: -0.16;1.00). The HHS Study is one of the first large randomized controlled trials targeting school environmental stressors. Potential implementation failures and the failures of the program theory are discussed.

Alcohol use among adolescents during the first pandemic lockdown in Denmark, May 2020

OBJECTIVE

As alcohol is often consumed for social purposes, we aimed to explore how restrictions during the first Danish COVID-19 lockdown affected the alcohol use among adolescents aged 15-20.

METHOD

In May 2020, 11,596 15- to 20-year-olds from two subpopulations answered a survey regarding their alcohol use and social life, as well as changes to these, during the Danish lockdown. Using survey data from all participants, we performed a multinomial logistic regression to assess the association between determinants of alcohol use and perceived change in alcohol use during the Danish lockdown. We used longitudinal data from one subpopulation (n=1869) to perform negative binomial regressions exploring changes in frequency of alcohol use from 2019 to 2020.

RESULTS

Of all participants, 59% drank less, 75% had fewer in-person social interactions and 56% met more frequently online during lockdown. Girls were more likely than boys to have a perceived decrease in alcohol use during lockdown (odds ratio (OR)=1.41; 95% confidence interval (CI) 1.27-1.56). A perceived decrease in in-person social interaction during lockdown was associated with less drinking (OR=2.27; 95% CI 1.98-2.61), while a perceived increase in in-person social interaction during lockdown was associated with more drinking (OR=1.42; 95% CI 1.11-1.82) compared to unchanged drinking behaviour and social interaction.

CONCLUSIONS

Adolescents in Denmark drank less during the Danish lockdown than before. Findings indicate that there is a close relationship between in-person social interactions and frequency of drinking. Drinking episodes when meeting online were rare and were not unambiguously associated with changes in drinking during lockdown.

Effect of the multicomponent healthy high school intervention on meal frequency and eating habits among high school students in Denmark: a cluster randomized controlled trial

Background

Previous studies have shown that multicomponent interventions may improve meal frequency and eating habits in children, but evidence among young people is limited. This study evaluated the effect of the Healthy High School (HHS) intervention on daily intake of breakfast, lunch, water, fruit, and vegetables at 9-month follow-up.

Methods

The study included first-year students (≈16 years) attending high school in Denmark. Participating schools were randomized into the HHS intervention (N = 15) or control group (operating as usual) (N = 15). The intervention was designed to promote well-being (primary outcome) by focusing on healthy habits including meals, stress prevention, and strong peer relations. It included a curriculum, structural and organisational initiatives, a workshop, and a smartphone application. Students completed self-administered online questionnaires at the beginning of the school year and nine months later. To account for clustering of data, we used multilevel logistic regression analyses to estimate odds ratios (OR). We applied an intention-to-treat approach with multiple imputations of missing data.

Results

At baseline 4577 of 5201 students answered the questionnaire and 4512 at follow-up. In both groups the proportion of students eating breakfast decreased from approximately 50% to 40% from baseline to follow-up, and lunch frequency decreased from approximately 50% to 47%. Daily water intake, intake of fresh fruit and intake of vegetables remained unchanged from baseline to follow-up. There were no significant between group differences on any of the outcomes at first follow-up: breakfast: OR = 0.85 (95% CI: 0.65;1.10), lunch: OR = 0.96 (95% CI: 0.75;1.22), water intake: OR = 1.14 (95% CI: 0.92;1.40), intake of fresh fruit: (OR = 1.07, 95% CI: 0.84;1.37), vegetables: (OR = 1.01, 95% CI: 0.77;1.33).

Conclusion

No evidence of an effect of the HHS intervention was found for any of the outcomes. Future studies are warranted to explore how health promoting interventions can be integrated in further education to support educational goals. Moreover, how to fit interventions to the lives and wishes of young people, by also including systems outside of the school setting.

Trial registration

ISRCTN, ISRCTN43284296. Registered 28 April 2017 - retrospectively registered.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12966-021-01228-2.

What characterizes schools and students participating in health promoting school-based intervention studies? Findings from the healthy high school study

The Healthy High School (HHS) intervention was developed to promote well-being among first-year high school students (~16 years of age) in Denmark by targeting stress, physical activity, meal habits, sleep, and sense of community. Thirty-one schools were randomly allocated to intervention (16 schools) or control (15 schools) groups in a cluster-randomized controlled trial. The purpose of this short communication was to compare characteristics of students and schools between 1) schools accepting to participate in the HHS study and non-participating schools using national survey data and 2) intervention and control schools using HHS baseline data. We included cross-sectional data from the Danish National Youth Study 2014 on 119 schools and 22,935 first-year students to characterize participating schools and students. At baseline (August 2016), students (n = 4577; 88.0%) and principals (n = 29; 96.7%) completed online questionnaires. Compared to non-participating schools, fewer HHS schools perceived their school as being popular and offered weekly sport activities outside school hours. More HHS schools had teachers engaged in health promotion activities and focused on stress prevention. The characteristics of HHS students did not differ markedly from non-participating high school students. There were no socio-demographic, outcome or contextual differences between the study arms. To ensure successful recruitment of schools it is important that the intervention meets the need of the schools and that the advantages of participation are explicit. This underlines the need for a thorough needs assessment prior to intervention development, co-creation of intervention activities with school staff, and a well-planned recruitment strategy.

Study protocol for a cluster randomised controlled trial testing the effectiveness of the 'High schools High on life' intervention on reducing excessive drinking in Danish high schools

INTRODUCTION

This paper describes the evaluation design of the 'High schools High on life' intervention; a school-based intervention to reduce excessive drinking among high school students in Denmark. The intervention includes a school environmental component to limit access to alcohol at school, a school-educational component to change social norms around alcohol among first year students and a parental component addressing parents' knowledge and attitudes towards alcohol.

METHODS AND DESIGN

The study will employ a cluster randomised controlled study design and will include a random sample of 16 high schools randomly allocated 1:1 to either intervention or control group. Target group: first year high school students. Timeline: baseline survey: January to March 2019, collected as part of the Danish National Youth Study 2019. Delivery of intervention: April 2019 to March 2020. Follow-up survey: April to May 2020.

PRIMARY OUTCOME MEASURE

30% reduction in mean number of binge-drinking episodes (five or more alcoholic drinks on one occasion) within the last 30 days.

SECONDARY OUTCOME MEASURES

proportion of students who drink alcohol, mean weekly alcohol consumption, alcohol intake at last school party, alcohol intake at the school during last school party, proportion of students who agree to be able to have fun at a party without drinking and the proportion of students who think alcohol plays a too dominant part at the school. Implementation will be monitored through process evaluation.

ETHICS AND DISSEMINATION

The Scientific Ethics Committees for the Capital Region of Denmark has declared that the trial is not subject to notification (jnr. 19021957). The study is registered at the Research an Innovation Office at University of Southern Denmark (ref: 10.314) allowing collection of personal data. Results will be published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT03906500.

Study protocol of the Healthy High School study: a school-based intervention to improve well-being among high school students in Denmark

BACKGROUND

The prevalence of low well-being, perceived stress and unhealthy behaviours is high among high school students, but few interventions have addressed these problems. The aim of this paper is to present a study protocol of a cluster randomised controlled trial evaluating the Healthy High School (HHS) intervention programme. The intervention programme is designed to improve well-being (primary outcome) by preventing 1) stress and promoting 2) sleep, 3) sense of community, 4) physical activity (PA) and 5) regular and healthy meals among high school students in Denmark.

METHODS

The development of the HHS study was guided by the Intervention Mapping protocol. The intervention comprises four components: 1) a teaching material, 2) a smartphone app, 3) a catalogue focusing on environmental changes, and 4) a peer-led innovation workshop aiming at inspiring students to initiate and participate in various movement activities. The HHS study employs a cluster-randomised controlled trial design. Thirty-one high schools across Denmark were randomly allocated to intervention (16 schools) or control (15 schools) groups. The study included all first-year students (~ 16 years of age) (n = 5976 students). Timeline: Intervention: August 2016 - June 2017. Collection of questionnaire data: Baseline (August 2016), 1st follow-up (May 2017) and 2nd follow-up (April 2018). All students were invited to participate in a monthly sub-study about perceived stress using text messages for data collection (September 2016 - June 2017). PA was objectively assessed among a sub-sample of students using accelerometers (Axivity, AX3) in August 2016 and May 2017.

PRIMARY OUTCOME MEASURES

Student well-being measured by the Cantril Ladder and the five item World Health Organisation Well-being Index (individual level outcomes).

SECONDARY OUTCOME MEASURES

Stress (10-item Perceived Stress Scale), sleep (quantity and quality), PA (hours of moderate-to-vigorous PA per week, hours of daily sedentary time and average daily PA), meal habits (daily intake of breakfast, lunch, snacks and water), and strong sense of community in class and at school, respectively (individual level outcomes). The study encompasses process and effect evaluation as well as health economic analyses.

TRIAL REGISTRATION

ISRCTN ISRCTN43284296, 28 April 2017, retrospectively registered.

Oral Lactobacillus Counts Predict Weight Gain Susceptibility: A 6-Year Follow-Up Study

BACKGROUND

Recent studies have shown an association between weight change and the makeup of the intestinal microbiota in humans. Specifically, Lactobacillus, a part of the entire gastrointestinal tract's microbiota, has been shown to contribute to weight regulation.

AIM

We examined the association between the level of oral Lactobacillus and the subsequent 6-year weight change in a healthy population of 322 Danish adults aged 35-65 years at baseline.

DESIGN

Prospective observational study.

RESULTS

In unadjusted analysis the level of oral Lactobacillus was inversely associated with subsequent 6-year change in BMI. A statistically significant interaction between the baseline level of oral Lactobacillus and the consumption of complex carbohydrates was found, e.g. high oral Lactobacillus count predicted weight loss for those with a low intake of complex carbohydrates, while a medium intake of complex carbohydrates predicted diminished weight gain. A closer examination of these relations showed that BMI change and Lactobacillus level was unrelated for those with high complex carbohydrate consumption.

CONCLUSION

A high level of oral Lactobacillus seems related to weight loss among those with medium and low intakes of complex carbohydrates. Absence, or a low level of oral Lactobacillus, may potentially be a novel marker to identify those at increased risk of weight gain.