title: Does the use of passive or active consent affect consent or completion rates, or dietary data quality? Repeat cross-sectional survey among school children aged 11-12 years.
abstract: OBJECTIVE
  An expectation of research is that participants should give fully informed consent. However, there is also a need to maximise recruitment to ensure representativeness. We explored the impact of passive or active parental consent on consent, completion rates and on dietary data quality in a survey among children aged 11-12 years.
  
  
  METHODS
  Six middle schools in North-East England.
  
  
  METHODS
  All children aged 11-12 years attending the six middle schools were eligible to participate (n=1141).
  
  
  RESULTS
  
  
  
  METHODS
  whether or not each eligible child's parent gave consent and provided a complete dietary diary; whether or not a child completed their dietary diary but only among children who agreed to participate, and whether or not children providing diaries were classified as an under-reporter or not.
  
  
  RESULTS
  Parents were more likely to consent passively than actively. This difference was greater among the more deprived: OR 16.9 (95% CI 5.7 to 50.2) in the least and 129.6 (95% CI 39.9 to 420.6) in the most deprived quintile (test for interaction: method of consent by level of deprivation, p=0.02). For all children eligible, completion was more likely if passive consent was used (OR 2.8, 95% CI 2.2 to 3.7). When only children who gave consent are considered, completion was less likely when passive rather than active consent was used (OR 0.6, 95% CI 0.4 to 0.9). Completion rate decreased as level of deprivation increased; we found no evidence that the OR for the method of consent varied by level of deprivation. There was no evidence that the quality of dietary data, as measured by an assessment of under-reporting, differed by method of consent (OR 0.8, 95% CI 0.5 to 1.2).
  
  
  CONCLUSIONS
  Passive consent led to a higher participation rate and a more representative sample without compromising data quality.
authors.affiliation: Institute of Health & Society, Human Nutrition Research Centre, Newcastle University, Newcastle upon Tyne, UK.
authors.forename: Suzanne
authors.initials: S
authors.lastname: Spence
authors.affiliation: Institute of Health & Society, Newcastle University, Newcastle upon Tyne, UK (Visiting Professor) Fuse, UKCRC Centre for Translational Research in Public Health, Newcastle upon Tyne, UK.
authors.forename: Martin
authors.initials: M
authors.lastname: White
authors.affiliation: Institute of Health & Society, Human Nutrition Research Centre, Newcastle University, Newcastle upon Tyne, UK Fuse, UKCRC Centre for Translational Research in Public Health, Newcastle upon Tyne, UK.
authors.forename: Ashley J
authors.initials: AJ
authors.lastname: Adamson
authors.affiliation: School of Mathematics and Statistics, Newcastle University, Newcastle upon Tyne, UK.
authors.forename: John N S
authors.initials: JN
authors.lastname: Matthews
mesh_terms: D002648:Child; D003430:Cross-Sectional Studies; D004032:Diet / Q000706:statistics & numerical data*; D015930:Diet Records; D004739:England; D005260:Female; D006306:Health Surveys / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D033282:Parental Consent / Q000706:statistics & numerical data*; D012107:Research Design / Q000706:statistics & numerical data*; D035842:Research Subjects / Q000706:statistics & numerical data*; D012959:Socioeconomic Factors
keywords: NUTRITION & DIETETICS; PUBLIC HEALTH; STATISTICS & RESEARCH METHODS