# Supply–demand governance of hierarchical healthcare systems: mobile big data unveils non-random patient flow patterns and the bypass premium in cities

## TL;DR

The study uses mobile data to show how patient flows in Shanghai are influenced by hospital hierarchy and administrative boundaries, leading to unequal healthcare access.

## Contribution

The novel bypass premium index quantifies structural barriers in patient flows, revealing hidden costs in urban healthcare systems.

## Key findings

- Patient flows are highly concentrated toward top-tier hospitals, deviating from random patterns.
- Administrative boundaries act as filters, funneling inter-district flows to tertiary hospitals.
- Secondary hospitals are functionally neutral, failing to divert patients effectively.

## Abstract

The uneven distribution of healthcare resources and jobs-housing spatial separation are reshaping the spatiotemporal patterns of urban patient flows. This structural mismatch exacerbates inequalities in service utilization and imposes hidden geographic and social costs. However, conventional static statistics and theoretical models often fail to capture authentic micro-level behavioral patterns, rendering them unable to precisely quantify or deconstruct the inequalities and burdens concealed within patient flows.

Taking Shanghai as a representative megacity case study, we utilized anonymized mobile signaling data (March 2019) to construct a weighted, directed “demand–supply” patient flows network. We introduced a null model as a random benchmark and employed the channel decomposition method to deconstruct pathway structures. We developed a “bypass premium” index to quantify the specific burden of quality-driven hospital seeking.

(1) Resource siphoning: Patient flows are highly concentrated toward top-tier hospitals, yet their spatial footprint is widely dispersed across the city, a pattern that deviates significantly from the random benchmark. (2) Boundary filtering: Administrative boundaries act as a “value filter.” Inter-district flows do not diffuse uniformly but are funneled into backbone pathways leading exclusively to tertiary hospitals. (3) Functional neutrality: Secondary hospitals fail to perform their intended hub-and-diversion function within the hierarchical healthcare system, resulting in a state of functional neutrality. (4) Cost deconstruction: The average bypass premium for reaching a tertiary hospital is 10.24 km. Crucially, 73.54% (7.53 km) of this constitutes passive structural friction required to overcome boundary barriers, while only 26.46% (2.71 km) represents the active selective premium paid for quality-driven access.

This study confirms the non-random polarization of patient flows and the screening mechanism of administrative boundaries in Shanghai. Our findings reveal that the costs of inter-district hospital-seeking stem primarily from passive structural friction rather than active selective premiums, occurring alongside a critical functional deficit in secondary hospitals. Consequently, policy interventions must prioritize strategies of “reducing friction” and “strengthening the middle.” Specifically, optimizing transportation networks, insurance integration, and medical consortiums is essential to dismantle barriers and revitalize the hub capacity of the intermediate tier.