title: Patient visibility and ICU mortality: a conceptual replication.
abstract: OBJECTIVE
  This study reanalyzes the data from a study by Leaf, Homel, and Factor (2010) titled "Relationship between ICU Design and Mortality" by adopting and developing objective visibility measures.
  
  
  BACKGROUND
  Various studies attribute healthcare outcomes (patient falls, satisfaction) to a vague notion of patient room visibility. The study by Leaf and colleagues was the first to draw an independent association between patient mortality and patient room visibility, however "visibility" remains imprecise.
  
  
  METHODS
  The original patient dataset was obtained from Dr. Leaf. The 664 patient sample assigned across 12 rooms at the medical ICU at Columbia University Medical Center was reanalyzed in terms of targeted visibility; the unit of analysis was the room, n = 12. Several computer-based visibility measures of patient rooms were used: patient head visibility, patient room visibility, and field of view to nursing station. Patient head visibility was defined as the percentage of area within the central nursing station from which the patient head could be seen; patient room visibility was defined as the percentage of area within the central nursing station that could see the patient room (average value of all patient room grids); field of view was defined as the maximum viewing angle from the patient head to the central nursing station.
  
  
  RESULTS
  Among the sickest patients (those with Acute Physiology and Chronic Health Evaluation II > 30), field of view accounted for 33.5% of the variance in ICU mortality, p = 0.049.
  
  
  CONCLUSIONS
  Subtle differences in patient room visibility may have important effects on clinical outcomes.
  
  
  BACKGROUND
  Case study, critical care/intensive care, methodology, outcomes.
authors.affiliation: CORRESPONDING AUTHOR: Yi Lu, PhD, Division of Building Science and Technology, City University of Hong Kong; Yi.Lu@cityu.edu.hk; (+852) 3442-7615.
authors.forename: Yi
authors.initials: Y
authors.lastname: Lu
authors.forename: Michelle M
authors.initials: MM
authors.lastname: Ossmann
authors.forename: David E
authors.initials: DE
authors.lastname: Leaf
authors.forename: Philip H
authors.initials: PH
authors.lastname: Factor
mesh_terms: D018806:APACHE; D005260:Female; D006749:Hospital Design and Construction / Q000706:statistics & numerical data*; D017052:Hospital Mortality; D006801:Humans; D007362:Intensive Care Units / Q000458:organization & administration*; D008297:Male; D010362:Patients' Rooms / Q000706:statistics & numerical data*