title: Reducing blood pressure with Internet-based interventions: a meta-analysis.
abstract: BACKGROUND
  Elevated blood pressure is a leading risk factor for cardiovascular disease and mortality. Internet-based interventions (e-counselling) have the potential to deliver a wide range of preventive counselling services. The purpose of this review was to (1) assess the efficacy of e-counselling in reducing blood pressure and (2) identify key components of successful trials in order to highlight factors that may contribute significantly to blood pressure control.
  
  
  METHODS
  MEDLINE, PubMed, EMBASE, PsycINFO, and the Cochrane Library were searched up to June 2012 with the following key words: Web-based, Internet-based, e-counselling, mobile health, blood pressure, and hypertension. Trials were selected in which blood pressure was reported as a primary or secondary outcome and whose participants had baseline systolic and diastolic blood pressure within the prehypertensive (120-139/80-89 mm Hg) or hypertensive (≥ 140/90 mm Hg) range.
  
  
  RESULTS
  The search strategy identified 13 trials, and the mean reduction of systolic and diastolic blood pressure was -3.8 mm Hg (95% confidence interval [Cl], -5.63 to -2.06 mm Hg; P < 0.01) and -2.1 mm Hg (95% CI, -3.51 to -0.65 mm Hg; P < 0.05), respectively. The greatest magnitude of blood pressure reduction was found for interventions that lasted 6 months or longer, used 5 or more behavior change techniques, or delivered health messages proactively.
  
  
  CONCLUSIONS
  Research on preventive e-counselling for blood pressure reduction is at an early stage of development. This review provides preliminary evidence of blood pressure reduction with Internet-based interventions. Future studies need to evaluate the contribution of specific intervention components in order to establish a best practice e-counselling protocol that is efficacious in reducing blood pressure.
authors.affiliation: Behavioural Cardiology Research Unit, University Health Network, Toronto, Ontario, Canada.
authors.forename: Sam
authors.initials: S
authors.lastname: Liu
authors.forename: Sarah D
authors.initials: SD
authors.lastname: Dunford
authors.forename: Yvonne W
authors.initials: YW
authors.lastname: Leung
authors.forename: Dina
authors.initials: D
authors.lastname: Brooks
authors.forename: Scott G
authors.initials: SG
authors.lastname: Thomas
authors.forename: Gunther
authors.initials: G
authors.lastname: Eysenbach
authors.forename: Robert P
authors.initials: RP
authors.lastname: Nolan
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001794:Blood Pressure / Q000502:physiology; D001795:Blood Pressure Determination; D003376:Counseling; D005260:Female; D015438:Health Behavior; D006801:Humans; D006973:Hypertension / Q000503:physiopathology / Q000517:prevention & control*; D020407:Internet; D008297:Male; D008875:Middle Aged; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult