title: How standard is standard care? Exploring control group outcomes in behaviour change interventions for young people with type 1 diabetes.
abstract: OBJECTIVE
  Poor descriptions of standard care may compromise interpretation of results in randomised controlled trials (RCTs) of health interventions. We investigated quality of standard care in RCTs of behaviour change interventions for young people with type 1 diabetes and consider implications for evaluating trial outcomes.
  
  
  METHODS
  We conducted systematic searches for articles published between 1999 and 2012. We extracted standard care descriptions and contacted trial authors to complete a checklist of standard care activities. The relationship between standard care quality and outcomes was examined via subgroup meta-analyses and meta-regression.
  
  
  METHODS
  Standard care descriptions, standard care quality, and relationships between standard care quality with medical and psychological outcomes.
  
  
  RESULTS
  We identified 20 RCTs described across 26 articles. Published descriptions of standard care were limited to service-level features. Author responses indicated standard care provision extended beyond published accounts. Subgroup analyses suggested control groups receiving higher standard care quality showed larger improvements in both medical and psychological outcomes, although standard care quality did not predict outcomes significantly.
  
  
  CONCLUSIONS
  The quality of care delivered to control group participants can influence outcomes of RCTs. Inadequate reporting exacerbates this issue by masking variations between trials. We argue for increased clarity in reporting standard care in future trials.
authors.affiliation: a Division of Primary Care, School of Medicine , University of Nottingham , Nottingham , UK.
authors.forename: K
authors.initials: K
authors.lastname: Ayling
authors.forename: S
authors.initials: S
authors.lastname: Brierley
authors.forename: B
authors.initials: B
authors.lastname: Johnson
authors.forename: S
authors.initials: S
authors.lastname: Heller
authors.forename: C
authors.initials: C
authors.lastname: Eiser
mesh_terms: D000293:Adolescent; D002648:Child; D035061:Control Groups; D003922:Diabetes Mellitus, Type 1 / Q000523:psychology* / Q000628:therapy*; D006801:Humans; D017063:Outcome Assessment, Health Care; D016032:Randomized Controlled Trials as Topic / Q000592:standards*; D059039:Standard of Care / Q000592:standards*; D055815:Young Adult
keywords: control group; meta-analysis; reporting; standard care quality; type 1 diabetes