Public Perception of Clinical Trials and Its Predictors Among Polish Adults.

: Public perception of clinical trials (CT) in Poland remains underexplored. This study aims to assess attitudes towards clinical trials, to identify key sociodemographic and health-related predictors of participation willingness, and to evaluate the perceived health impact (CT-PHI) associated with participants' involvement in trials. : A cross-sectional online survey was conducted (2-20 March 2022) among 2050 Polish adults who had benefited from medical care in the past 24 months. This study examined sociodemographic factors, health-related factors (self-perceived health, EQ-5D-5L, the level of awareness of patient rights, use of public vs. private healthcare, adherence), and motivations for participation in trials (health-related, financial, and altruistic). Multivariate logistic and generalized linear models identified predictors of participation willingness and CT-PHI variability. : Overall, 56.3% of the respondents expressed a willingness to participate in clinical trials. The main motivation was health improvement (45.8%), followed by financial incentives (23.2%) and altruism (22.7%). Those driven by health reasons showed the highest sensitivity to demographic and health-related factors. In this group, higher CT-PHI scores were associated with older age (66+: B = 1.24, < 0.001), female gender (B = 0.41, = 0.034), rural residence (B = 0.41, = 0.033), dual use of public/private healthcare (B = 0.64, = 0.001), adherence (B = 2.50, < 0.001), and greater pain severity (moderate: B = 1.36, < 0.001; severe: B = 0.91, = 0.023). Socioeconomic factors played a greater role for financially motivated individuals, while altruistic participants showed the least variability in influencing factors. : Willingness to participate in clinical trials in Poland is influenced by the motivation type. A patient-centered approach to recruitment strategies, considering diverse motivations and sociodemographic factors, is essential for optimizing participation in clinical trials.