Latent class analysis of polysubstance use and association of various risk factors with polysubstance use among vocational students in Northern Thailand by sex differences and factors association

Background: Using multiple substances carries higher risks and health consequences than using a single substance. This study aims to identify polysubstance user subgroups among vocational students in northern Thailand and evaluate associated risk factors by gender. Methods: This study was conducted among Thai vocational students. Latent class analysis (LCA) was utilized to identify classes of polysubstance use. Results: The questionnaire was completed by 2399 male and 1213 female respondents. LCA revealed distinct patterns of polysubstance use between male and female adolescents. A four-class solution was the best-fitting model for males: class 1 (1.42%) was characterized as the polysubstance user (all types) group; class 2 (22.23%) included the predominant alcohol and tobacco user group; class 3 (5.37%) formed the predominant alcohol, tobacco, cannabis, and kratom user group; and class 4 (70.98%) comprised the nonuser group. For females, a three-class solution was the best fit: class 1 (1.55%) included the polysubstance user (all types) group; class 2 (80.94%) comprised the nonuser group; and class 3 (17.51%) represented the predominant alcohol and tobacco user group. Factors that significantly increased the risk of polysubstance use among both male and female adolescents (p < 0.05) were positive attitudes toward polysubstance use and tobacco or cannabis as their first substance used. Conclusion: Thailand should enforce existing legislation strictly and effectively to limit youth access to tobacco. It is important to provide medical information about the negative health effects of recreational cannabis use. Keywords: Adolescent, Drug abuse, Latent class analysis, Substance use, Vocational education