The following factors were included as covariates for potential confounders or risk factors: sex (male or female), grade (7th, 8th, 9th, 10th, 11th, or 12th), academic performance (high, middle, or low), area of residence (metropolitan, urban, or rural), residence type (living with or without family), economic status (high, middle, or low), subjective health condition (healthy, normal, or unhealthy), physical activity over 1 h and five times per week (yes or no), drinking experience (yes or no), smoking status (never, ex-smoker, or current smoker), sleep satisfaction (satisfied, regular, or unsatisfied), stress perception (high, middle, or low), depressive symptoms in the past 12 months (yes or no), and year (2020, 2021, 2022, or 2023)
Codes are everywhere
Many cigarettes also have various chemical additives which alter the flavor, make the nicotine more addictive, and enhance the burning properties of the blend
It is not exactly clear what withdrawing its PMDD indication means
Bioinformatic methods also showed applications in investigating the impact of tobacco smoke on regulatory factors associated with gene expression in various ways, for example, an aberration in DNA methylation (49, 71, 72), transcriptional binding sites (73), and noncoding RNA (70, 74, 75)
