Impact of daylight illumination on reducing patient length of stay in hospital after coronary artery bypass graft surgery, Lighting Research and Technology

In this research, a field investigation was done with 263 coronary artery bypass graft (CABG) surgery patients to identify the impact of daylight exposure on patient length of stay (LoS) in hospital. Lighting data were collected by installing sensors inside in-patient rooms, and were used to develop a multiple linear regression (MLR) model to explore the relationship between daylight intensity and patient LoS in the presence of other environmental (i.e. provision of outdoor view and room status) and clinical (i.e. mean arterial pressure, heart rate and diabetes mellitus) variables. The coefficient estimates of the developed MLR model suggest that while holding the other explanatory variables constant, the patient LoS reduced by 7.3 hours per 100 lx increase of daylight inside in-patient rooms.