*2.2. Sample Size*

Purposeful sampling methods were used. The study universe comprised a total of 7479 students. The sample size was calculated taking into account the statistical formula for prevalence of a known universe using the Grammo program (https://www.imim. es/ofertadeserveis/software-public/granmo/, accessed on 1 September 2020). It was increased by 20% to account for possible losses. Obtaining a minimum sample size of 366 students was thus sufficient to estimate a representative population mean, with 95% confidence and a margin of error of 5.
