Table 2 Key structural network ﬁndings for health network quality and safety Network feature Brokerage Centrality Degrees of separation Density Diffusion Homophily Hierarchy Integration and cliques Multiplexity Network roles Key structural ﬁndings for health network quality and safety Important in bridging connections and obviating ‘structural holes’ in hospitals Good coding performance is associated with a knowledge sharing network structure rich in brokerage and hierarchy, rather than density Centrality of key organisations or actors in a network is important, and can be a strength or potential vulnerability for network sustainability Directors of nursing are more central in their networks than clinical directors of medicine and their networks are more hierarchicaldhence better adapted to gathering and disseminating information The higher the centrality of the hospital in its network, the better the hospital performance Analysis of ‘degrees of separation’ can show the level of connectivity in a professional network The denser the GP network the lower the variation in performance Clinical directors of medicine are embedded in more densely connected networks (cliques), than directors of nursing, and can be stronger instruments for changing, or resisting changes, in clinical behaviour. Networks of directors of nursing have lower density, with advantages in accessing information Ideological tension can block the spread of knowledge and new work practices within the professional network Gaps in the network of informal ties will impede the dissemination of information and the spread of social inﬂuence between nurse executives and physician leaders, while non-clinical managers have a brokerage role People seek advice, or inﬂuence or discuss important professional matters with those similar to themselves (profession, gender, age, seniority), with implications for communication exchanges Physician leaders have more extreme homophily than senior nurses A large number of people in the network seek information from particular individuals For health professional teams other than medicine, collaboration on problem-solving and decision-making is limited to higher status professionals Nursing networks are more hierarchical than medical networks Relationships between groups of agencies, services or providers (cliques) in a network may be more important than the relationship between all agencies in the network SNA can identify agencies and actors who are not well linked in the network Employees forming a greater number of ties with co-workers are more embedded and have lower turnover Individual roles in networks are important for communication and information dissemination: ‘broker’ and ‘bridging’ roles, ‘cliques’, ‘isolates’ BMJ Qual Saf 2012;21:239e249. doi:10.1136/bmjqs-2011-000187 Systematic review Studies Heng et al (2005),26 West and Barron (2005),27 Rangachari (2008)28 Cott (1997),29 Creswick and Westbrook (2007),30 Creswick et al (2009),31 Gold et al (2008),32 Lewis et al (2008),33 Mendel et al (2009),34 Mossholder et al (2005),35 Webster et al (1999),36 West and Barron (2005),27 West et al (1999),37 Peng et al (2006)38 Creswick et al (2009)31 Fattore et al (2009),39 West et al (1999),37 West and Barron (2005)27 Ormrod et al (2007),40 West and Barron (2005)27 Chase (1995),41 Cott (1997),29 Creswick and Westbrook (2007),30 Creswick et al (2009),31 MacPhee (2000),42 MacPhee and Scott (2002),43 Webster et al (1999),36 West and Barron (2005),27 West et al (1999)37 Creswick and Westbrook (2007),30 Cott (1997),29 West et al (1999)37 Calloway et al (1999),44 Lemieux-Charles et al (2005),45 Milward and Provan (1998),46 West et al (1999)37 Mossholder et al (2005)35 Gold et al (2008),32 Heng et al (2005),26 Mendel et al (2009),34 Lewis et al (2008),33 West et al (1999),37 West and Barron (2005)27 Continued 243