Acceptability, feasibility, and effectiveness of a co-designed gamified app to monitor cannabis and tobacco use: GAM-CaT Study


Cannabis is the most consumed illegal drug in Spain. In recent years, there has been an increase in the number of people who enroll in substance abuse programs because they want to stop or reduce their cannabis use. Most cannabis users are also tobacco users and the pattern of co-use of both substances is becoming more frequent in occidental countries. However, the characterization of this consumption pattern and the withdrawal symptoms associated with the dual use of both substances has been poorly described; among other reasons due to the complexity of the ways of consumption and the multitude of products used to consume both cannabis and tobacco, which makes it difficult to distinguish withdrawal symptoms between the two substances.


Main objective

To evaluate the acceptability, feasibility, and effectiveness of a co-designed gamified mobile application (app) aimed at the clinical follow-up of people who start a process of cessation or reduction of cannabis use, to monitor their pattern and changes in consumption, withdrawal syndrome, and adherence to treatment.



Mixed-methods research composed of three studies.

Study I: qualitative participatory action study aimed at exploring the experiences and preferences of the cannabis users on the use of apps. This information will be instrumental in the co-design of the gamified app.

Study II: prospective longitudinal study aimed at evaluating the implementation (acceptability, fidelity, etc.) of the app and its effectiveness in studying the changes in several behavioral outcomes (abstinence, reduction of cannabis-tobacco use, etc.) in comparison to an historical cohort. Sample size: expected RR=1.20, α =0.05, β= 0.20, losses= 20% (n=282). Analysis: incidence, relative risk through Cox regression models (RR and 95% confidence interval) and Machine Learning to estimate the probability of changes (relapse/reducing).

Study III: phenomenological study to explore participants’ experiences with thematic content analysis and final triangulation of qualitative and quantitative results.



3 years (january2022-2024)



FIS PI21/00699  of 62.920,00 €


Principal Investigator and Coordination Center
Dr. Cristina Martínez, l’ Institut Català d’Oncologia (ICO)


Research team

Cristina Martínez, Institut Català d’Oncologia (IP)

Montse Ballbè, Institut Català d’Oncologia

Ariadna Feliu, Institut Català d’Oncologia

Yolanda Castellano, Institut Català d’Oncologia

Judith Saura, Institut Català d’Oncologia

Marta Enríquez, Institut Català d’Oncologia

Marga Pla, Universitat de Barcelona

Petia Radeva, Universitat de Barcelona

Elena Maestre, Universitat de Barcelona

Ana Andrés, Universitat Ramon Llull

Joseph Guydish, University of Califòrnia San Francisco

Joan Colom, Agència de Salut Pública de Catalunya

Carmen Cabezas, Agència de Salut Pública de Catalunya

Xavier Roca, Hospital de la Santa Creu i Sant Pau

Silvia Mondon, Hospital Clínic i Provincial de Barcelona

Magalí Andreu , Hospital Clínic i Provincial de Barcelona

Pablo Barrio , Hospital Clínic i Provincial de Barcelona

Jordi Bernabeu , Fundació Althaia

Antònia Raich, Fundació Althaia

Jordi Vilaplana, Universitat de Lleida