Objective: To determine whether adolescent smoking behaviour is associated with their perceived exposure to teachers or other pupils smoking at school, after adjustment for exposure to smoking at home, in school, and best friends smoking. Design: Logistic regression analysis of cross sectional data from students in Denmark. Subjects: 1515 grade 9 students (mean age 15.8) from 90 classes in 48 Danish schools. Outcome measure: Self reported smoking behaviour; daily smoking and heavy smoking, defined as those smoking more than 20 cigarettes per week. Results: Of the students in this study, 62% of boys and 60% of girls reported being exposed to teachers smoking outdoors on the school premises. The proportion of boys and girls reporting to have been exposed to teachers smoking inside the school building were 86% and 88%, respectively. Furthermore, 91% of boys and 92% of girls reported that they had seen other students smoking outdoors on the school premises. Adolescents' perceived exposure to teachers smoking outdoors on the school premises was significantly associated with daily smoking, having adjusted for sex, exposure to teachers smoking indoors at school and pupils smoking outdoors at school, as well as the smoking behaviour of mother, father, and best friend (odds ratio (OR) 1.8, 95% confidence interval 1.2 to 2.8). Adolescents' perceived exposure to teachers smoking inside the school building was not associated with daily smoking (OR 0.9, 95% CI 0.5 to 1.6) and perceived exposure to pupils smoking outdoors was not associated with daily smoking (adjusted OR 1.5, 95% CI 0.5 to 4.4). There were similar findings with heavy smoking as the outcome variable. Conclusions: Teachers smoking during school hours is associated with adolescent smoking. This finding has implications for future tobacco prevention strategies in schools in many countries with liberal smoking policies where it might provide support for those working to establish smokefree schools.T he health effects of smoking are well documented and it is estimated that half of those who smoke and fail to stop will die from their habit.1 Given that most smokers take up the habit before they reach the age of 18 years, one of the most important strategies in reducing smoking prevalence in the population has been to prevent young people from becoming smokers.2 After a period of stability in adolescent smoking prevalence in western Europe, it would appear that the rate of smoking among young people has risen in recent years in many countries.3 4 In 1994, the proportion of smokers among Danish adolescents aged 15 was 33% for girls and 25% for boys; by 1998, these proportions had changed to 38% for boys and 31% for girls.4 5 These trends indicate the need for new smoking prevention strategies based on a more rigorous understanding of the factors which influence adolescents' initiation of smoking.In their review of predictors of onset of adolescent smoking, Conrad et al identified a variety of factors that might influence young people to smoke: sociodemographic factor...

Background Horses with non‐strangulating intestinal infarction (NSII) are often misdiagnosed with idiopathic peritonitis or acute colitis. Early diagnosis is essential to ensure early surgical intervention and improve survival. Methods Clinical and laboratory data from horses admitted to the University of Copenhagen Large Animal Teaching Hospital with NSII, idiopathic peritonitis or acute colitis between 2009 and 2018 were used for univariate comparisons and a multivariable logistic regression model for prediction of NSII. Results Two hundred and thirty‐one horses were included. A multivariable model for the prediction of NSII included gastric reflux (more than 5 L) (odds ratio [OR] 8.7; 95% confidence interval [CI] 2.1–36.2), abnormal findings palpated per rectum (intestinal dilatations/impactions [OR 4.43; 95% CI 1.43–13.38], colon displacements [OR 23.16; 95% CI 5.26–101.97] or intestinal mass [OR 179.7; 95% CI 23.5–1375.5]), white blood cell count (OR 1.2; 95% CI 1.1–1.4), packed cell volume (OR 0.9; 95% CI 0.8–0.9), age (OR 0.9; 95% CI 0.8–1.0) and heart rate (OR 1.1; 95% CI 1.0–1.1). The model had a low false positive rate (5%), but a high false negative rate (50%). Limitations Due to the retrospective nature of the study, sample collection was inconsistent, resulting in missing values. Conclusion The model had some capability in predicting NSII. However, the high risk of false negatives means that exploratory laparotomy should be considered in horses with peritonitis of unknown aetiology in areas where Strongylus vulgaris is prevalent and occurrence of idiopathic peritonitis is low.