Various studies have attribute healthcare outcomes (patient falls, satisfaction) to a vague notion of patient room visibility. Until 2010, however, no evidence existed that this was the case. “Relationship between ICU Design and Mortality” (Leaf, Homel, & Factor, 2010) was the first study to implicate patient visibility, defined as seen or unseen from the central nurses' station, as a factor influencing patient mortality. Yet the definition of “visibility” remains imprecise.

This new study is a conceptual replication that seeks to graphically quantify and characterize visibility, while validating the significance and meaning of these graph measures against the data obtained by Leaf and colleagues.

In this conceptual replication, the unit of analysis was the patient room; thus all the original outcome measures were aggregated at the patient room level. The new outcome measures included hospital mortality rate, ICU morality rate, and average length of stay for each patient room. The authors conclude that subtle differences in patient room visibility may have important effects on clinical outcomes. Field of view appears to independently affect patient outcome. Patient head visibility, room visibility, and field of view enable comparisons between patient rooms with degrees of differential visibility and respect the continuous nature of visibility. Furthermore, these measures only need an accurate floor plan drawing to perform a visibility assessment. This allows designers to consider alternatives and allows clients to assess proposals based on a visibility analysis to avoid patient rooms with low or no visibility from the central nurses' station.

Edited abstract from “Patient Visibility and ICU Mortality: A Conceptual Replication," by To access the entire report, click here to subscribe to the The Health Environments Research and Design (HERD) Journal. The HERD Journal, a sister publication to Healthcare Design, is an interdisciplinary, peer-reviewed journal whose mission is to enhance the knowledge and practice of evidence-based healthcare design by disseminating research findings, discussing issues and trends, and translating research to practice.