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An Emergent Network for the Diffusion of Innovations Among Local Health Departments at the Onset of the COVID-19 Pandemic


The largest node for opinion-leading LHDs is in the Pacific Northwest. Other large nodes are in southern California, southern Texas, the central United States, and 2 are in the northeastern seaboard. A smaller node that is both opinion-leading and boundary-spanning is in the central United States. Four small boundary-spanning nodes are in the central and east-central United States, and one is in the Southwestern United States. Most LHDs did not perform either of these roles.

Figure 1.

Advice-seeking networks among local health departments (LHDs) in the United States identified in a survey of 329 health departments through the National Association of County and City Health Officials, 2020. The size of a node reflects the opinion leadership (number of nominations received) of each LHD. Lines indicate advice-seeking relationships between an LHD and others, and arrowheads show the direction of advice-seeking. Number of lines indicate number of LHDs seeking advice from an LHD.

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The large, interconnected group of LHDs consists of one LHD with many nominations and many urban LHDs with fewer nominations, with many rural LHDs connected to them. Many other small, disconnected groups of urban and rural LHDs are also shown; each group consists of roughly 2 to 10 urban and rural LHDs, although a few groups are exclusively rural.

Figure 2.

Urban and rural representation of local health departments (LHDs). Node size reflects the number of nominations an LHD received from senior leaders of other LHDs. The distinction was based on the rural–urban commuting area codes retrieved from the US Department of Agriculture (14). Node size corresponds to number of in-degree ties.

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The opinions expressed by authors contributing to this journal do not necessarily reflect the opinions of the U.S. Department of Health and Human Services, the Public Health Service, the Centers for Disease Control and Prevention, or the authors’ affiliated institutions.

Page last reviewed: March 4, 2021