title: The Norwegian Healthy Life Study: protocol for a pragmatic RCT with longitudinal follow-up on physical activity and diet for adults.
abstract: The Norwegian Directorate of Health recommends that Healthy Life Centres (HLCs) be established in primary health care to support behaviour change and reduce the risk of non-communicable diseases. The aim of the present study protocol is to present the rationale, design and methods of a combined pragmatic randomized controlled trial (RCT) and longitudinal cohort study of the effects of attending HLCs concerning physical activity, sedentary behaviour and diet and to explore how psychological well-being and motivational factors may mediate short- and long-term effects.
  
  
  
  The present study will combine a 6-month RCT with a longitudinal cohort study (24 months from baseline) conducted at six HLCs from June 2014 to Sept 2017. Participants are randomized to behavioural change interventions or a 6-month waiting list control group.
  
  
  
  A randomized trial of interventions in HLCs has the potential to influence the development of policy and practice for behaviour change interventions and patient education programmes in Norway. We discuss some of the important preconditions for obtaining valid results from a complex intervention and outline some of the characteristics of ecological approaches in health care research that can enable a pragmatic intervention study.
  
  
  
  The study was retrospectively registered on September 19, 2014 and is available online at ClinicalTrials.gov (ID: NCT02247219 ).
authors.affiliation: Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway. eirik.abildsnes@kristiansand.kommune.no.
authors.forename: Eirik
authors.identifier: 0000-0002-5454-8560
authors.initials: E
authors.lastname: Abildsnes
authors.affiliation: Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway.
authors.forename: Eivind
authors.initials: E
authors.lastname: Meland
authors.affiliation: Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway.
authors.forename: Thomas
authors.initials: T
authors.lastname: Mildestvedt
authors.affiliation: Department of Public Health, Sport and Nutrition, University of Agder, Kristiansand, Norway.
authors.forename: Tonje H
authors.initials: TH
authors.lastname: Stea
authors.affiliation: Department of Public Health, Sport and Nutrition, University of Agder, Kristiansand, Norway.
authors.forename: Sveinung
authors.initials: S
authors.lastname: Berntsen
authors.affiliation: Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway.|Department for research and development, Haukeland University Hospital, Bergen, Norway.
authors.forename: Gro Beate
authors.initials: GB
authors.lastname: Samdal
mesh_terms: D000328:Adult; D001521:Behavior Therapy; D003142:Communication; D000072001:Diet, Healthy / Q000523:psychology*; D015444:Exercise / Q000523:psychology*; D005260:Female; D005500:Follow-Up Studies; D015438:Health Behavior; D006293:Health Promotion / Q000379:methods*; D006801:Humans; D008019:Life Style; D008297:Male; D008603:Mental Health; D009042:Motivation; D009664:Norway; D010353:Patient Education as Topic; D011320:Primary Health Care; D011788:Quality of Life; D012107:Research Design; D012306:Risk; D040242:Risk Reduction Behavior
keywords: Adults; Diet; Health behaviour; Physical activity; Randomized control trial