title: Effectiveness of Interventions to Decrease Emergency Department Visits by Adult Frequent Users: A Systematic Review.
abstract: Frequent emergency department (ED) users are high-risk and high-resource-utilizing patients. This systematic review evaluates effectiveness of interventions targeting adult frequent ED users in reducing visit frequency and improving patient outcomes.
  
  
  
  An a priori protocol was published in PROSPERO. Two independent reviewers screened, selected, rated quality, and extracted data. Third-party adjudication resolved disagreements. Rate ratios of post- versus pre-intervention ED visits were calculated. Data sources were from a comprehensive search that included seven databases and the gray literature. Eligibility criteria for selecting studies included experimental studies assessing the effect of interventions on frequent users' ED visits and patient-oriented outcomes.
  
  
  
  A total of 6,865 citations were identified and 31 studies included. Designs were noncontrolled (n = 21) and controlled (n = 4) before-after studies and randomized controlled trials (n = 6). Frequent user definitions varied considerably and risk of bias was moderate to high. Studies examined general frequent users or those with psychiatric comorbidities, chronic disease, or low socioeconomic status or the elderly. Interventions included case management (n = 18), care plans (n = 8), diversion strategies (n = 3), printout case notes (n = 1), and social work visits (n = 1). Post- versus pre-intervention rate ratios were calculated for 25 studies and indicated a significant visit decrease in 21 (84%) of these studies. The median rate ratio was 0.63 (interquartile range = 0.41 to 0.71), indicating that the general effect of the interventions described was to decrease ED visits post-intervention. Significant visit decreases were found for a majority of studies in subgroup analyses based on 6- or 12-month follow-up, definition thresholds, clinical frequent user subgroups, and intervention types. Studies reporting homelessness found consistent improvements in stable housing. Overall, interstudy heterogeneity was high.
  
  
  
  Interventions targeting frequent ED users appear to decrease ED visits and may improve stable housing. Future research should examine cost-effectiveness and adopt standardized definitions.
authors.affiliation: Department of Emergency Medicine, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Jessica
authors.initials: J
authors.lastname: Moe
authors.affiliation: Emergency Medicine Research Group, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Scott W
authors.initials: SW
authors.lastname: Kirkland
authors.affiliation: Department of Emergency Medicine, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Erin
authors.initials: E
authors.lastname: Rawe
authors.affiliation: Respiratory Health Strategic Clinical Network, Alberta Health Services, Edmonton, Alberta, Canada.
authors.forename: Maria B
authors.initials: MB
authors.lastname: Ospina
authors.affiliation: Alberta Research Centre for Health Evidence, Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Ben
authors.initials: B
authors.lastname: Vandermeer
authors.affiliation: J. W. Scott Health Sciences Library, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Sandy
authors.initials: S
authors.lastname: Campbell
authors.affiliation: Department of Emergency Medicine, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Brian H
authors.initials: BH
authors.lastname: Rowe
mesh_terms: D000328:Adult; D000368:Aged; D065187:Controlled Before-After Studies; D003362:Cost-Benefit Analysis; D004636:Emergency Service, Hospital / Q000191:economics / Q000706:statistics & numerical data*; D005260:Female; D006295:Health Resources; D006801:Humans; D000069342:Medical Overuse / Q000517:prevention & control*; D016032:Randomized Controlled Trials as Topic; D012306:Risk