Medline Database n=2290 Medline Database n=609 CINAHL Database n=1325 CINAHL Database n=218 Stage 1 Search: Social Networks EMBASE Database n=1722 Web of Science Database n=7831 EMBASE n=153 Web of Science Database n=367 Stage 1 Search results Social Networks (total)=14 607 for Stage 2 search using key terms Stage 2 Search results Social Networks-Health Professionals=1560 for title and abstract review Social Networks-Health Professionals (after exclusion criteria)= 82 (Medline =41; CINAHL=6; EMBASE=11; Web of Science=22; Business Source Premier=2) Systematic review Business Source Premier Database n=1439 Business Source Premier Database n=213 Full text content analysis of all search results n=66 Systematic analysis of the research literature n=26 1478 articles excluded: - non-human, missing abstract, missing author , non-English - patient, client, caregiver networks - descriptions of health service networks - non-health professionals - internet social networking - university-based students, education - academics, research scientists - infection control, epidemiological networks - bio-networks, neural networks - e-health systems and software 16 duplicates removed 40 articles excluded: 25: not meeting quality inclusion criteria 12: not on structure of health professional networks 2: excluded in count (3 belonged to 1 study); 1: excluded in count (2 belonged to 1 study) Figure 1 Flowchart of systematic review. BMJ Qual Saf 2012;21:239e249. doi:10.1136/bmjqs-2011-000187 241