Background Despite the multimodality approach to drug treatment and rehabilitation in Hong Kong, there is a lack of empirical study analysing multiproject data for taxonomy development and effect size evaluation. Given the importance of developing and implementing effective drug treatment and rehabilitation approaches, this study had two aims (a) to develop a taxonomy for categorising drug treatment and rehabilitation programmes and (b) to determine the effect sizes of different programme categories in reducing drug use frequency. Methods The study employed a mixed method with both descriptive qualitative study design and secondary data analysis of outcomes among 1605 participants from 16 projects. Results Drug treatment and rehabilitation programmes in Hong Kong were categorised into psychosocial, medical and competence approaches based on the intensity of different intervention sessions. In comparison with the competence approach, psychosocial treatments yielded greater immediate estimates in the past month and smaller long‐term estimates in the past 6 months. Medical treatments showed greater intermediate estimates than psychosocial treatments in the past 3 months. Conclusions The study was a pioneer in categorising drug treatment and rehabilitation projects and evaluating their pre–post reductions in drug use frequency, thereby equipping researchers, practitioners and policymakers with a more holistic understanding of practical evidence in drug use and contributing to the translation of a theoretical framework into practice.
Luo et al. (2026) studied this question.