Representation of the hierarchical and functional structure of an ambulatory network of medical consultations through social network analysis, with an emphasis on the role of medical specialties

Background Ambulatory Health Care Networks (Amb-HCN) emerge when doctors establish circuits of patient referral and counter-referral in their offices, explicitly or spontaneously. We aimed to characterize the structural and functional topology of an Amb-HCN of a private health insurance provider (PHIP) using objective metrics from graph theory. Methods A Social Network Analysis was conducted with administrative claim data of a Brazilian PHIP. Included were beneficiaries of a healthcare plan not restricting the location or physician caring for the patient. A directional and weighted network was constructed, where doctors were vertices and patient referrals between doctors were edges. Vertex-level measures were calculated and grouped into three theoretical constructs: patient follow-up; relationship with authorities; and centrality profiles. To characterize physicians into these profiles, cluster analysis was conducted using the non-hierarchical K-means technique. Findings Between 04/01/2021 and 05/15/2022, 666,263 individuals performed 3,863,222 office visits with 4,554 physicians. Non-primary-care medical specialties (e.g., cardiology, endocrinology etc.) were associated with central profile in the graph, while surgical specialties predominated in the periphery, along with pediatrics. Only pediatrics was associated with strong and prevalent patient follow-up. Weak and shared patient follow-up was present for many doctors from internal medicine and family medicine. All profiles exhibited pairwise relationships with each other, and with clinical characteristics and outcomes of the patients they treated. For example, physicians identified as authorities were frequently central and treated patients with more comorbidities. Eleven medical communities were identified with clear territorial and medical specialty segregation. Conclusions Viewing the Amb-HCN as a social network provided emerging insights into the most influential actors and specialties, potential gaps in care, and the most prevalent diseases in our patient portfolio. Identifying self-constituted Amb-HCN can form a rational basis for developing more formal networks or monitoring patient care performance without assigning responsibility to single physicians.