Is Blood Thicker Than Water? The Influence of Kin Within a Bull Shark Social Network.

Fever of unknown origin (FUO) continues to pose a significant diagnostic challenge worldwide (). Defined as a prolonged fever without an identifiable source despite a thorough evaluation, FUO affects a substantial proportion of adult patients globally. FUO evaluation always begins with a comprehensive medical history, physical examination, and initial diagnostic investigations. While physicians should energetically pursue the final diagnosis (), the etiology remains unknown in 10–50% of FUO patients, and this figure is increasing (). Moreover, the diagnostic process for FUO is often lengthy and resource-intensive, with over 200 potential causes ranging from infections and malignancies to autoimmune diseases and other conditions (). For many patients, the prolonged uncertainty itself becomes a source of anxiety, frustration, and reduced quality of life (). Physicians also face considerable cognitive and emotional stress as they navigate uncertain diagnostic pathways and balance thorough investigation with patient expectations and safety. In such complex diagnostic landscapes, shared decision-making (SDM)—a collaborative process in which physicians and patients make health decisions together based on clinical evidence and patient preferences—has emerged as a valuable tool to enhance trust, communication, and patient-centered care (). Originally conceptualized in the context of preference-sensitive decisions in chronic diseases such as cancer, cardiovascular disease, and mental health, SDM has since been widely endorsed across diverse clinical settings (). In pediatric care, particularly when managing acute febrile illnesses in children, SDM has shown promise in reducing unnecessary antibiotic use and improving parental satisfaction (). However, existing SDM models predominantly operate under the premise of a confirmed diagnosis, focusing primarily on treatment selection, such as drug selection in cardiovascular diseases or surgical options in cancer. In contrast, adult FUO presents a unique challenge: SDM must address prolonged diagnostic ambiguity (), weigh the risks and benefits of increasingly invasive or expensive investigations, and manage patient anxiety across a broad differential diagnosis (, ). Despite the critical need for collaborative uncertainty management, the application of SDM in adult FUO remains strikingly unexplored. Unlike Western healthcare systems, where SDM is deeply rooted in individual autonomy and supported by longer consultations, implementation in China faces unique systemic barriers (). Chinese general hospitals operate under extreme patient volumes and severe time constraints, with infectious disease departments managing the majority of adult FUO cases. Within this high-pressure environment, physicians must navigate clinical ambiguity while balancing thorough investigation with patient expectations. Consequently, structured SDM may facilitate transparent communication and ethically sound care in complex diagnostic scenarios.