Efficacy of a multicomponent nature-based intervention on well-being and environmental engagement: A randomized clinical trial

BACKGROUND: Nature-based interventions (NBIs) benefit human well-being, but clinical trials comparing different NBIs in various natural environments are scarce. OBJECTIVE: To evaluate the efficacy of a multicomponent nature-based intervention (MNBI) in comparison to control group (classical forest bathing). PRIMARY OUTCOME: well-being; Secondary outcomes: vitality, happiness, connection, and engagement with nature across urban, peri-urban, and rural areas. METHODS: Randomized clinical trial with 486 participants between October/2022 and June/2023, from five natural areas in Southeast and Southern/Brazil. Well-being was assessed immediately before the activity and 30 days after, and secondary outcomes immediately before, immediately after and 30 days after. The data analyses considered a 95 % confidence interval and p-values < 0.05. RESULTS: The main hypothesis was confirmed, well-being levels of MNBI group were significantly improved, especially in peri-urban areas (p = 0.036). Both groups increased vitality (p < 0.001), but MNBI was more effective overall (p = 0.038), especially in urban areas (p = 0.020). Happiness increased in both groups (p = 0.001), but MNBI participants maintained higher levels 30 days post-intervention (p = 0.010). Nature connection increased significantly in both groups (p < 0.001) but remained higher in MNBI after 30 days (p = 0.021), especially in peri-urban areas (p = 0.034). While both groups reported calm and relaxation, MNBI uniquely fostered learning, knowledge, and contemplation. CONCLUSIONS: MNBI was more effective than classical forest bathing in improving well-being, nature connection and pro-environmental behaviors, particularly in peri-urban settings, expanding the potential of NBIs for well-being promotion. CLINICALTRIALS REGISTRATION: NCT05486156.