Smoking Behavior and Major Cardiovascular and Limb Events in Patients With Peripheral Artery Disease

Importance: Smoking is the strongest modifiable risk factor for peripheral arterial disease (PAD), yet evidence on how postdiagnosis smoking behavior changes affect clinical outcomes remains limited. Objective: To evaluate the association among smoking cessation, reduction, and continuation after PAD diagnosis and subsequent cardiovascular and limb-specific outcomes. Design, Setting, and Participants: This nationwide, population-based, retrospective cohort study assessed adults 40 years or older newly diagnosed with PAD from January 1, 2011, to December 31, 2018, with follow-up through 2021, who reported active smoking before diagnosis and completed health examinations before and after diagnosis. Data were from the Korean National Health Insurance Service-National Health Information Database. Data analysis was conducted from December 2023 to November 2025. Exposures: Postdiagnosis smoking behavior, classified as quitters (complete cessation), reducers (≥20% decrease in daily cigarette consumption), or maintainers (