Network contagion influences on chronic illness care in large physician practices

Objectives: Care management processes (CMPs) are evidenced-based methods of physician practice redesign consistent with principles of the Chronic Care Model. National surveys have found minimal use of these processes in large multi-specialty physician organizations. Physician groups enter into interorganizational relationships and little is known regarding the impact these relationships on CMP use in the practice. This study examined the influence of shared ties in a managed care network on similarity of practice behavior in the treatment of patients with asthma, congestive heart failure, diabetes and depression in physician organizations.

Methods: Network analysis methods examined the exchange relationships of physician organizations in the managed care network in California in 2006. Physician group ties with other physicians, hospitals, and health maintenance organizations were analyzed using affiliation matrices for each year. Multivariate regression analyses examined associations of network relationships and similarity in practice behavior between physician organization dyads.

Findings: Network effects were found to influence CMP prevalence and homogeneity in their use. CMP use was positively associated with ties to other physicians and with hospitals. Dyads with shared hospital system affiliations were more similar in their practice for chronic illness care than non-connected dyads. Shared HMO ties were negatively associated with similarity in CMP use.

Conclusion: Findings provide support to the current quality reform discussions surrounding the development of Accountable Care Organizations (ACOs). Greater interorganizational linkages among providers of health care services may encourage diffusion of quality practices in the care of patients with chronic conditions.