title: Do windows or natural views affect outcomes or costs among patients in ICUs?
abstract: OBJECTIVE
  To determine whether potential exposure to natural light via windows or to more pleasing views through windows affects outcomes or costs among critically ill patients.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  An academic hospital in Philadelphia, PA.
  
  
  METHODS
  Six thousand one hundred thirty-eight patients admitted to a 24-bed medical ICU and 6,631 patients admitted to a 24-bed surgical ICU from July 1, 2006, to June 30, 2010.
  
  
  METHODS
  Assignment to medical ICU rooms with vs. without windows and to surgical ICU rooms with natural vs. industrial views based on bed availability.
  
  
  RESULTS
  In primary analyses adjusting for patient characteristics, medical ICU patients admitted to rooms with (n = 4,093) versus without (n = 2,243) windows did not differ in rates of ICU (p = 0.25) or in-hospital (p = 0.94) mortality, ICU readmissions (p = 0.37), or delirium (p = 0.56). Surgical ICU patients admitted to rooms with natural (n = 3,072) versus industrial (n = 3,588) views experienced slightly shorter ICU lengths of stay and slightly lower variable costs. Instrumental variable analyses based on initial bed assignment and exposure time did not show any differences in any outcomes in either the medical ICU or surgical ICU cohorts, and none of the differences noted in primary analyses remained statistically significant when adjusting for multiple comparisons. In a prespecified subgroup analysis among patients with ICU length of stay greater than 72 hours, MICU windows were associated with reduced ICU (p = 0.02) and hospital mortality (p = 0.04); these results did not meet criteria for significance after adjustment for multiple comparisons.
  
  
  CONCLUSIONS
  ICU rooms with windows or natural views do not improve outcomes or reduce costs of in-hospital care for general populations of medical and surgical ICU patients. Future work is needed to determine whether targeting light from windows directly toward patients influences outcomes and to explore these effects in patients at high risk for adverse outcomes.
authors.affiliation: Department of Medicine, Massachusetts General Hospital, Boston, MA, USA.
authors.forename: Rachel
authors.initials: R
authors.lastname: Kohn
authors.forename: Michael O
authors.initials: MO
authors.lastname: Harhay
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Cooney
authors.forename: Dylan S
authors.initials: DS
authors.lastname: Small
authors.forename: Scott D
authors.initials: SD
authors.lastname: Halpern
mesh_terms: D000368:Aged; D005260:Female; D006749:Hospital Design and Construction / Q000191:economics / Q000706:statistics & numerical data*; D017052:Hospital Mortality; D006801:Humans; D007362:Intensive Care Units / Q000191:economics / Q000706:statistics & numerical data*; D007902:Length of Stay; D008029:Lighting / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D016896:Treatment Outcome