title: The impact of communicating genetic risks of disease on risk-reducing health behaviour: systematic review with meta-analysis.
abstract: OBJECTIVE
  To assess the impact of communicating DNA based disease risk estimates on risk-reducing health behaviours and motivation to engage in such behaviours.
  
  
  METHODS
  Systematic review with meta-analysis, using Cochrane methods.
  
  
  METHODS
  Medline, Embase, PsycINFO, CINAHL, and the Cochrane Central Register of Controlled Trials up to 25 February 2015. Backward and forward citation searches were also conducted.
  
  
  METHODS
  Randomised and quasi-randomised controlled trials involving adults in which one group received personalised DNA based estimates of disease risk for conditions where risk could be reduced by behaviour change. Eligible studies included a measure of risk-reducing behaviour.
  
  
  RESULTS
  We examined 10,515 abstracts and included 18 studies that reported on seven behavioural outcomes, including smoking cessation (six studies; n=2663), diet (seven studies; n=1784), and physical activity (six studies; n=1704). Meta-analysis revealed no significant effects of communicating DNA based risk estimates on smoking cessation (odds ratio 0.92, 95% confidence interval 0.63 to 1.35, P=0.67), diet (standardised mean difference 0.12, 95% confidence interval -0.00 to 0.24, P=0.05), or physical activity (standardised mean difference -0.03, 95% confidence interval -0.13 to 0.08, P=0.62). There were also no effects on any other behaviours (alcohol use, medication use, sun protection behaviours, and attendance at screening or behavioural support programmes) or on motivation to change behaviour, and no adverse effects, such as depression and anxiety. Subgroup analyses provided no clear evidence that communication of a risk-conferring genotype affected behaviour more than communication of the absence of such a genotype. However, studies were predominantly at high or unclear risk of bias, and evidence was typically of low quality.
  
  
  CONCLUSIONS
  Expectations that communicating DNA based risk estimates changes behaviour is not supported by existing evidence. These results do not support use of genetic testing or the search for risk-conferring gene variants for common complex diseases on the basis that they motivate risk-reducing behaviour.
  
  
  BACKGROUND
  This is a revised and updated version of a Cochrane review from 2010, adding 11 studies to the seven previously identified.
authors.affiliation: Behaviour and Health Research Unit, University of Cambridge, Cambridge, UK.
authors.forename: Gareth J
authors.initials: GJ
authors.lastname: Hollands
authors.affiliation: School of Psychological Sciences, University of Manchester, Manchester, UK.
authors.forename: David P
authors.initials: DP
authors.lastname: French
authors.affiliation: Department of Public Health and Primary Care, University of Cambridge, Cambridge, UK.
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Griffin
authors.affiliation: Imperial Clinical Trials Unit, Imperial College London, London, UK.
authors.forename: A Toby
authors.initials: AT
authors.lastname: Prevost
authors.affiliation: Department of Public Health and Primary Care, University of Cambridge, Cambridge, UK.
authors.forename: Stephen
authors.initials: S
authors.lastname: Sutton
authors.affiliation: Behaviour and Health Research Unit, University of Cambridge, Cambridge, UK.
authors.forename: Sarah
authors.initials: S
authors.lastname: King
authors.affiliation: Behaviour and Health Research Unit, University of Cambridge, Cambridge, UK tmm388@cam.ac.uk.
authors.forename: Theresa M
authors.initials: TM
authors.lastname: Marteau
mesh_terms: D020022:Genetic Predisposition to Disease / Q000453:epidemiology* / Q000523:psychology; D005820:Genetic Testing; D015438:Health Behavior; D006266:Health Education; D057220:Health Literacy; D006801:Humans; D009042:Motivation; D010353:Patient Education as Topic; D011322:Primary Prevention / Q000379:methods*; D016032:Randomized Controlled Trials as Topic; D012307:Risk Factors; D040242:Risk Reduction Behavior