Smoking after lung transplantation: Incidence and risk factors in the French multicenter prospective tabatransplant cohort study

Background: Smoking is a major contributor to respiratory diseases requiring lung transplantation (LTx). Data on smoking after LTx are scarce. Understanding the incidence and determinants of smoking after LTx is crucial for optimizing long-term outcomes. Methods: For this prospective observational cohort study done from March 2023 to August 2024 in 11 French transplantation (Tx) centers, LTx and heart-lung transplant (HLTx) recipients completed an anonymous self-administered questionnaire during their routine follow-up. Pre- and post-Tx smoking and sociodemographic characteristics were collected and analyzed centrally. Results: Of 946 recipients with complete data on smoking, 524 (55%) reported having smoked before Tx. Among them, approximately 5% smoked after LTx. Smoking after Tx was significantly associated with several demographic and contextual factors, including female sex, younger age, living alone, having cystic fibrosis, prior use of hand-rolled cigarettes, and regular exposure to smokers among family and friends. By multivariate analysis, younger age, living alone, and smoking among family and friends were associated with post-Tx smoking. Due to the anonymous completion of the self-administered questionnaires, associations between post-Tx smoking and clinical outcomes could not be assessed. Conclusions: This study provides novel multicenter data about the incidence and determinants of smoking after LTx or HLTx. A small but meaningful proportion of recipients smoked after Tx. We identified several social and demographic risk factors. Our findings highlight the need for targeted smoking-relapse prevention-and-support programs in lung and heart-lung recipients. Further research is warranted to evaluate the impact of smoking after Tx on graft and patient outcomes.