Objective: To explore the associations of characteristics of the cluster environment with new psychoactive substances (NPS) use in Thailand.

Materials and Methods: A cross-sectional study was done on 30,411 Thai people, stratified in multi-stage cluster sampling. Trained interviewers conducted a semi-structured interview in 2016. A multilevel binary logistic regression model was employed to estimate the effects of the cluster environment on the NPS use.

Results: NPS was widely used. The past month prevalence was 13.6%, and habitual use was 4.4%. Clustering significantly affects the spread of NPS use. Controlling for cluster effects, a likelihood of current NPS use was associated with elementary education, occupation, and reported health problems. While a higher likelihood of habitual NPS use was associated with elementary education, employed, and perceived mental health problem.

Conclusion: NPS use was influenced by characteristics of the cluster environment. Therefore, demand reduction strategies should be designed based on a consideration of the impact of cluster context on NPS use behaviors.

Keywords: Cluster effect, New psychoactive substance, NPS, Thailand

DOI: doi.org/10.35755/jmedassocthai.2021.02.11592

Received 30 June 2020 | Revised 8 September 2020 | Accepted 9 September 2020