Coalitions, alliances and… silos? Identifying patterns in public health collaboratives

March 4, 2015

Public health collaboratives (PHCs) bring together diverse partners to apply multi-systemic tactics to public health outcomes. Given the reality of scarce resources and the interdisciplinary nature of public health, this type of interorganizational approach has great value.

A recent study poses a question, however: within such networks, do member organizations self-segregate according to type?

Dr. Christine Bevc

Dr. Christine Bevc

Christine Bevc, PhD, MA, epidemiologist research associate at the UNC Gillings School of Global Public Health’s N.C. Institute for Public Health, is lead author of the study, “New Perspectives on the ‘Silo Effect’: Initial Comparisons of Network Structures Across Public Health Collaboratives,” published online Feb. 17 in the American Journal of Public Health.

The study investigates how accurately findings from previous research on networks can be applied to PHCs. Typically, network members exhibit homophily, or the propensity to form the strongest ties with the most similar members of the group, thereby establishing silos. In other words, likeness breeds connection. This tendency potentially could undermine PHC goals related to identifying innovative solutions.

Bevc and her co-authors used social network analysis to explore the interaction patterns between partners in 162 PHCs. They identified 15 unique organization types and used these to measure network diversity and the silo effect.

On average, the PHCs contained only four different organizational types. While diversity did increase along with network size, study results suggest an accompanying increase in the time and effort expended to maintain relationships within a larger network.

Analysis also revealed which types of organizations are more likely to establish silos within a collaborative group. Public health entities are among the most prone to exhibit similar partner preferences. As network size increases, this silo effect becomes more pronounced.

Given the increased work load and additional siloing common to large PHCs, it is crucial to take steps to prevent diminished effectiveness. Strategic management is required at both the network and individual organization levels to reap the full benefits of the collaborative advantage.

The study authors recommend further research to better understand the ways networks form and evolve. Knowing how certain types of organizations tend to interact with similar partners is a first step in developing education and training about how to avoid the silo effect and accomplish collective goals.

Bevc and collaborating authors are currently continuing their investigation of PHC partnerships, examining the complementary patterns of heterophily in the formation of diverse and innovative collaborative partnerships.

Co-authors include Jessica Retrum, MSSW, PhD, assistant professor in the Department of Social Work at Metropolitan State University in Denver, and Danielle Varda, PhD, associate professor in the School of Public Affairs at the University of Colorado in Denver.

Gillings School of Global Public Health contact: David Pesci, director of communications, (919) 962-2600 or

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