{Reference Type}: Journal Article {Title}: Assessing the impact of the Physician Payments Sunshine Act on pharmaceutical companies' payments to physicians. {Author}: Cheng S;Duan W;Zhou W; {Journal}: PLoS One {Volume}: 19 {Issue}: 8 {Year}: 2024 {Factor}: 3.752 {DOI}: 10.1371/journal.pone.0306886 {Abstract}: Enacted in 2010 as part of the Affordable Care Act, the Physician Payments Sunshine Act (PPSA) mandates transparency in financial interactions between pharmaceutical companies and healthcare providers. This study investigates the PPSA's effectiveness and its impact on industry payments to physicians. Utilizing ProPublica and Open Payments databases, a difference-in-difference analysis was conducted across ten states. Results reveal a significant reduction in pharmaceutical companies' meal-related payments post-PPSA, impacting both the total payment amount and the number of unique physicians reached. Conversely, travel payments showed no significant impact in the primary analysis. However, subsequent analyses revealed nuanced reductions in the number of unique physicians reached, highlighting a more intricate relationship wherein pharmaceutical companies likely adjusted their financial interaction strategies with physicians differently across states. State-level variations in meals further underscore the complexity of PPSA's influence. This pioneering research contributes valuable empirical evidence, addressing gaps in prior studies and emphasizing the ongoing need for policy assessment to guide industry-physician relationships.