METHODS
The methods of the GAN study have been already published elsewhere12 and are mainly identical to those of ISAAC. GAN is cross-sectional study based on written questionnaires distributed in schools in the participating centres. In Kosovo, the survey included the age group of 13-14-years; and six centres: Ferizaj, Gjakova, Gjilan, Peja, Prishtina and Prizren. The fieldwork was carried out between 2017 and 2018.