variables. In the initial study, network stability moderated the impact of resources. In the 2003 study, an effective network was one with enough stability to maintain its ability to manage a set of jointly produced services. Another study in a US mental healthcare setting44 used SNA to compare two rural and four urban care systems for people with severe mental disorders (SMDs). Both rural sites had numerous coordination linkages between the two types of provider groups (SMD and other service providers) for service planning and delivery. Density scores revealed the extent of service dependency when providers coordinated care to people with SMD in rural sites compared with urban sites. Service relationships among all specialised mental health providers were more likely to occur in rural than urban areas. A study of chief executive ofﬁcers in all accredited Taiwanese hospitals38 examined the impact of hospital resources, network resources and centrality on hospital performance. Hospital resources and centrality inde- pendently affected performance, whereas network resources did not. For that setting, the authors conclude that a hospital should improve performance by exploiting its in-house resources rather than obtaining network resources externally, and should occupy a central position to create a structural niche. Health professionals and social context Half of the studies (13) examined health professionals and social context, including six on work climate. Chase41 used ethnography in two intensive care units (ICUs) in a US teaching hospital to analyse structure and communication patterns relating to the social context in which the process of critical care clinical judgement occurred from the nurse’s perspective. With multiple clinicians involved in ICU patient-care decision-making, parallel hierarchies of nurses and of doctors allowed for checks on judgement both within and across profes- sional lines. Also, rituals (nursing reports, physician rounds, ﬂow sheet use) provided a context to check judgement processes. Lurie et al55 applied SNA to three settings in one US clinical institution: team function in the ICU, the interdisciplinary composition of advisory committees, and relationships between key function directors. Researchers used SNA to compare teams on aspects of their clinical team functioning, and to show the degree of inter-disciplinarity of various clinical departments on the advisory committees. SNA identiﬁed potential problem areas with gaps in knowledge of functional roles among academic departments. SNA was employed by Cott29 to describe the structure of three multi-disciplinary, long-term care teams in a Canadian geriatric care facility. Effects of teamwork in BMJ Qual Saf 2012;21:239e249. doi:10.1136/bmjqs-2011-000187 Systematic review sharing decision-making were limited to a group of higher status health professionals other than medicine, with the clearly deﬁned hierarchy remaining for lower status sub-disciplines. Garrett and McDaniel49 conducted a cross-sectional study of ﬁve units in a US hospital to explore the relationships of environmental uncertainty, nurse characteristics and perceived work climate with professional burnout. Environmental uncertainty and perceptions of social-work climate were associated with burnout, yet ﬁndings suggested a positive social network climate could shield workers from the negative effects of crisis. Mossholder et al35 applied SNA and survival analysis to study healthcare employees in a large public US medical centre, examining whether structural, attitudinal and behavioural variables of a relational nature were predictive of employee turnover. Two variables, network centrality and interpersonal citizenship behaviour, predicted turnover with effects above and beyond the effects of job satisfaction. Workers forming more ties with coworkers (network centrality) became more embedded and had lower turnover, and higher interpersonal citizenship behaviour resulted in lower turnover. A study of physicians in four German hospitals analysed the relationship between overall job satisfaction of physicians and social capital in the hospitals.48 Job satisfaction was signiﬁcantly associated with professional experience, and with lower workloads. The social capital of an organisation was a signiﬁcant predictor of overall job satisfaction of physicians. In a similar research area, Swedish studies50e52 investigated whether psychosocial work conditions, professional network, job support, social network and support, sick leave and salary were associated with work stress in nurses in chief manager positions and physicians in clinical director positions. For both roles, a signiﬁcant association was found between exposure to high job demands and a high level of work stress. Here, available psychosocial resources, inside and outside work, did not balance the experi- enced work stress in nurse managers and clinical directors exposed to high work demands. The work of nurses with ﬂexible and traditional schedules was compared in a US case study in an urban paediatric acute-care hospital.42 Applying SNA to examine the types of social networks used by both groups of nurses and to compare their workplace socialisation, no signiﬁcant differences were found in the nurses’ social network composition. However, tradi- tional nurses used signiﬁcantly more peer members for different types of emotional support. MacPhee and Scott43 also applied SNA to examine workplace social support networks of rural hospital nurses, compared with the urban nurse networks. Rural nurses’ networks 245