title: Impact on decisions to start or continue medicines of providing information to patients about possible benefits and/or harms: a systematic review and meta-analysis.
abstract: The impact of providing information about medicines to patients on decisions about starting or continuing them is unknown.
  
  
  
  To estimate the impact on decisions to start or continue medicines, of providing information to patients about possible benefits and/or harms.
  
  
  
  Electronic searches from 1980 to October 2010; reference and citation searches of included studies.
  
  
  
  Two investigators assessed studies' eligibility against inclusion criteria: randomized or pseudorandomized trials; participants older than 16 years and deciding for themselves; one group received information about possible benefits and/or harms of a potentially beneficial medicine, compared with another who did not; d) a measure of decision about starting or continuing a medicine.
  
  
  
  One investigator extracted all data, checked by a second.
  
  
  
  Eight studies were included, covering a range of medicines. There was no consistent impact of interventions on decisions about whether to start or continue medicines (pooled odds ratio 1.08; 95% confidence interval [CI], 0.69-1.70; P = 0.74). Among those who received more information, knowledge was increased (pooled mean difference 8.47; 95% CI 2.17-14.77; P = 0.008), and decisional conflict was reduced (pooled mean difference -0.15; 95% CI -0.24 to -0.06; P = .001).
  
  
  
  A small number of studies across different clinical contexts, of uncertain heterogeneity, were included.
  
  
  
  Providing information to patients about possible benefits and/or harms has no consistent effect on the number who decide to start or continue medicines, although it increases patients' knowledge and reduces their decisional conflict.
authors: Psychology Department (at Guy’s), Health Psychology Section, King’s College London, London, UK (RAC, TMM)
authors: Rachel A
authors: RA
authors: Crockett
authors: General Practice and Primary Care Research Unit, Department of Public Health and Primary Care, University of Cambridge, Cambridge, UK (SS, FMW, MC, JB)
authors: Stephen
authors: S
authors: Sutton
authors: General Practice and Primary Care Research Unit, Department of Public Health and Primary Care, University of Cambridge, Cambridge, UK (SS, FMW, MC, JB)
authors: Fiona M
authors: FM
authors: Walter
authors: General Practice and Primary Care Research Unit, Department of Public Health and Primary Care, University of Cambridge, Cambridge, UK (SS, FMW, MC, JB)
authors: Megan
authors: M
authors: Clinch
authors: Psychology Department (at Guy’s), Health Psychology Section, King’s College London, London, UK (RAC, TMM)
authors: Theresa M
authors: TM
authors: Marteau
authors: General Practice and Primary Care Research Unit, Department of Public Health and Primary Care, University of Cambridge, Cambridge, UK (SS, FMW, MC, JB)
authors: John
authors: J
authors: Benson
mesh_terms: D003657:Decision Making; D004358:Drug Therapy; D006801:Humans; D010353:Patient Education as Topic