Box 2.

Physician and hospital network metrics included in combined model for predicting evidence-based ICD utilization.

Unit	Metric	Interpretation
Hospital	Closeness centrality	The efficiency at which patient-sharing ties connect the hospital to all other hospitals in their network
	Homophily coefficient by family practice	The likelihood of sharing patients among family practice physicians
ICD capable physician	Node strength	The number of clinical encounters a provider has with patients who are cared for by his/her patient-sharing connections in the hospital network
	Closeness centrality	The efficiency at which patient-sharing ties connect the ICD capable physician to all other providers in the hospital network

Note: The network metric(s) that had the largest effect within each category (even if it did not reach statistical significance of p<0.05) was included in the combined model to demonstrate how various network metrics can be used as predictors in models of evidence-based care.