title: Current use was established and Cochrane guidance on selection of social theories for systematic reviews of complex interventions was developed.
abstract: To identify examples of how social theories are used in systematic reviews of complex interventions to inform production of Cochrane guidance.
  
  
  
  Secondary analysis of published/unpublished examples of theories of social phenomena for use in reviews of complex interventions identified through scoping searches, engagement with key authors and methodologists supplemented by snowballing and reference searching. Theories were classified (low-level, mid-range, grand).
  
  
  
  Over 100 theories were identified with evidence of proliferation over the last 5 years. New low-level theories (tools, taxonomies, etc) have been developed for classifying and reporting complex interventions. Numerous mid-range theories are used; one example demonstrated how control theory had changed the review's findings. Review-specific logic models are increasingly used, but these can be challenging to develop. New low-level and mid-range psychological theories of behavior change are evolving. No reviews using grand theory (e.g., feminist theory) were identified. We produced a searchable Wiki, Mendeley Inventory, and Cochrane guidance.
  
  
  
  Use of low-level theory is common and evolving; incorporation of mid-range theory is still the exception rather than the norm. Methodological work is needed to evaluate the contribution of theory. Choice of theory reflects personal preference; application of theory is a skilled endeavor.
authors.affiliation: School of Social Sciences, Bangor University, Bangor LL57 2EF, UK. Electronic address: j.noyes@bangor.ac.uk.
authors.forename: Jane
authors.initials: J
authors.lastname: Noyes
authors.affiliation: North Wales Centre for Primary Care Research, Bangor University, Bangor, UK.
authors.forename: Maggie
authors.initials: M
authors.lastname: Hendry
authors.affiliation: School of Health & Related Research (ScHARR), University of Sheffield, Regent Court, 30 Regent Street, Sheffield S1 4DA, UK.
authors.forename: Andrew
authors.initials: A
authors.lastname: Booth
authors.affiliation: The Cochrane Editorial Unit, Cochrane Central Executive, St Albans House, 57-59 Haymarket, London SW1Y 4QX, UK.
authors.forename: Jackie
authors.initials: J
authors.lastname: Chandler
authors.affiliation: Global Health Unit, Norwegian Knowledge Centre, Norwegian Institute of Public Health, PO Box 4404, Nydalen, N-0403 Oslo, Norway.
authors.forename: Simon
authors.initials: S
authors.lastname: Lewin
authors.affiliation: Global Health Unit, Norwegian Knowledge Centre, Norwegian Institute of Public Health, PO Box 4404, Nydalen, N-0403 Oslo, Norway.
authors.forename: Claire
authors.initials: C
authors.lastname: Glenton
authors.affiliation: European Centre for Environment and Human Health, University of Exeter, Knowledge Spa, Royal Cornwall Hospital, TruroTR1 3HD, UK.
authors.forename: Ruth
authors.initials: R
authors.lastname: Garside
mesh_terms: D015340:Epidemiologic Research Design; D006801:Humans; D012196:Review Literature as Topic; D066269:Social Theory
keywords: Cochrane; Complex intervention; Guidance; Methodology; Systematic review; Theory