title: Realist theory construction for a mixed method multilevel study of neighbourhood context and postnatal depression.
abstract: BACKGROUND
  We have recently described a protocol for a study that aims to build a theory of neighbourhood context and postnatal depression. That protocol proposed a critical realist Explanatory Theory Building Method comprising of an: (1) emergent phase, (2) construction phase, and (3) confirmatory phase. A concurrent triangulated mixed method multilevel cross-sectional study design was described. The protocol also described in detail the Theory Construction Phase which will be presented here.
  
  
  METHODS
  The Theory Construction Phase will include: (1) defining stratified levels; (2) analytic resolution; (3) abductive reasoning; (4) comparative analysis (triangulation); (5) retroduction; (6) postulate and proposition development; (7) comparison and assessment of theories; and (8) conceptual frameworks and model development.
  The stratified levels of analysis in this study were predominantly social and psychological. The abductive analysis used the theoretical frames of: Stress Process; Social Isolation; Social Exclusion; Social Services; Social Capital, Acculturation Theory and Global-economic level mechanisms. Realist propositions are presented for each analysis of triangulated data. Inference to best explanation is used to assess and compare theories. A conceptual framework of maternal depression, stress and context is presented that includes examples of mechanisms at psychological, social, cultural and global-economic levels. Stress was identified as a necessary mechanism that has the tendency to cause several outcomes including depression, anxiety, and health harming behaviours. The conceptual framework subsequently included conditional mechanisms identified through the retroduction including the stressors of isolation and expectations and buffers of social support and trust.
  
  
  CONCLUSIONS
  The meta-theory of critical realism is used here to generate and construct social epidemiological theory using stratified ontology and both abductive and retroductive analysis. The findings will be applied to the development of a middle range theory and subsequent programme theory for local perinatal child and family interventions.
authors.affiliation: Community Paediatrics, Sydney Local Health District, Croydon Community Health Centre, 24 Liverpool Road, Croydon, NSW 2132 Australia ; School of Public Health and Community Medicine, The University of New South Wales, Sydney, NSW 2052 Australia ; School of Women's and Children's Health, The University of New South Wales, Sydney, NSW 2052 Australia ; Ingham Institute of Applied Medicine, The University of New South Wales, Liverpool, NSW 2170 Australia ; School of Public Health, The University of Sydney, Sydney, NSW 2006 Australia ; School of Medicine, Griffith University, Gold Coast, QLD 4222 Australia.
authors.forename: John G
authors.initials: JG
authors.lastname: Eastwood
authors.affiliation: Ingham Institute of Applied Medicine, The University of New South Wales, Liverpool, NSW 2170 Australia ; School of Nursing and Midwifery, Western Sydney University, Campbelltown, NSW 2560 Australia.
authors.forename: Lynn A
authors.initials: LA
authors.lastname: Kemp
authors.affiliation: School of Public Health and Community Medicine, The University of New South Wales, Sydney, NSW 2052 Australia ; Ingham Institute of Applied Medicine, The University of New South Wales, Liverpool, NSW 2170 Australia.
authors.forename: Bin B
authors.initials: BB
authors.lastname: Jalaludin