title: Associations between in-hospital bed occupancy and unplanned 72-h revisits to the emergency department: a register study.
abstract: BACKGROUND
  A possible downstream effect of high in-hospital bed occupancy is that patients in the emergency department (ED) who would benefit from in-hospital care are denied admission. The present study aimed at evaluating this hypothesis through investigating associations between in-hospital bed occupancy at the time of presentation in the ED and the probability for unplanned 72-hour (72-h) revisits to the ED among patients discharged at index. A second outcome was unplanned 72-h revisits resulting in admission.
  
  
  METHODS
  All visits to the ED of a 420-bed emergency hospital in southern Sweden between 1 January 2011 and 31 December 2012, which did not result in admission, death, or transfer to another hospital were included. Revisiting fractions were computed for in-hospital occupancy intervals <85%, 85% to 90%, 90% to 95%, 95% to 100%, 100% to 105%, and ≥105%. Multivariate models were constructed in an attempt to take confounding factors from, e.g., presenting complaints, age, referral status, and triage priority into account.
  
  
  RESULTS
  Included in the study are 81,878 visits. The fraction of unplanned 72-h revisits/unplanned 72-h revisits resulting in admission was 5.8%/1.4% overall, 6.2%/1.4% for occupancy <85%, 6.4%/1.5% for occupancy 85% to 90%, 5.8%/1.4% for occupancy 90% to 95%, 6.0%/1.6% for occupancy 95% to 100%, 5.4%/1.6% for occupancy 100% to 105%, and 4.9%/1.4% for occupancy ≥105%. In the multivariate models, a trend to lower probability of unplanned 72-h revisits was observed at occupancy ≥105% compared to occupancy <95% (OR 0.88, CI 0.76 to 1.01). No significant associations between in-hospital occupancy at index and the probability of making unplanned 72-h revisits resulting in admission were observed.
  
  
  CONCLUSIONS
  The lack of associations between in-hospital occupancy and unplanned 72-h revisits does not support the hypothesis that ED patients are inappropriately discharged when in-hospital beds are scarce. The results are reassuring as they indicate that physicians are able to make good decisions, also while resources are constrained.
authors.affiliation: Department of Clinical Science Lund, Lund University, Hs 32, EA-blocket, Plan 2, Lund 22185, Sweden.
authors.forename: Mathias C
authors.initials: MC
authors.lastname: Blom
authors.affiliation: Department of Emergency, Helsingborg Hospital, S Vallgatan 5, Helsingborg 25187, Sweden.
authors.forename: Fredrik
authors.initials: F
authors.lastname: Jonsson
authors.affiliation: Department of Clinical Science Lund, Lund University, Hs 32, EA-blocket, Plan 2, Lund 22185, Sweden.
authors.forename: Mona
authors.initials: M
authors.lastname: Landin-Olsson
authors.affiliation: Department of Clinical Science Lund, Lund University, Hs 32, EA-blocket, Plan 2, Lund 22185, Sweden.
authors.forename: Kjell
authors.initials: K
authors.lastname: Ivarsson
keywords: Bed occupancy; Emergency medicine; Emergency medicine/organization and administration; Emergency medicine/statistics and numerical data