Metrics of the Social Contact Networks of Patients and Staff in the Emergency Department Open Access

Hill, Eric DuBois (2011)

Permanent URL: https://etd.library.emory.edu/concern/etds/g445cd92z?locale=en
Published

Abstract

Patients who go to the emergency department are often waiting in overcrowded waiting rooms with other patients. This presents a major opportunity for the spread of respiratory disease. Emergency departments have not done an adequate job in isolating infectious patients. Understanding how a disease propagates though an emergency department is a very important step in managing disease outbreaks. Mathematical models have become important tools in this regard, but with their focus on differential-equation models and equal mixing of populations, we miss the true picture on how populations interact with each other and how disease transmits in a varied population. In an emergency department, patients would have different interactions with other patients than with hospital
staff. Social network models may be more useful in predicting disease transmission in an emergency department.
An important step in the development of network models is accurately measuring interactions between and within groups of patients and healthcare workers. The goal of this thesis was to report metrics of networks of patient and emergency department staff during 82 12-hour shifts at the emergency department at Midtown Hospital, in Atlanta, GA. A radio frequency tracking system was used to accurately track patients and staff in the emergency department. We looked at several social network factors: degree, diameter, shortest path, clustering coefficient, and density. In addition, another goal of this thesis was to assess any differences that might exist in our metric by time of year, AM or PM shift, whether it was H1N1 influenza season, weekend or weekday shift, and day of the week. We used generalized estimating equations (GEE) to assess differences in our data. GEEs take into account the correlations we expect to find among patient to patents interaction groups, staff to patients interaction groups, and staff to staff interaction groups. We found that the mean shortest path increased significantly over time, which implies that the number of individuals between any two people in the ED increased over time, decrease the probability that an individual would contact an infectious person in the ED. No other differences were observed.

Table of Contents

3



Table of Contents
Introduction .......................................................................................................................................... 1
Respiratory Illness in the Emergency Department (ED) ............................................................... 1
Problem Statement ....................................................................................................................... 2
Purpose Statement ....................................................................................................................... 3
Objectives ...................................................................................................................................... 3
Objective 1 ............................................................................................................................ 3
Objective 2 ............................................................................................................................ 4
Literature Review .................................................................................................................................. 4
Background ................................................................................................................................... 4
Weighted Networks ...................................................................................................................... 5
Network Components ................................................................................................................... 6
Network Centrality ........................................................................................................................ 7
Degree ................................................................................................................................... 7
Distance ................................................................................................................................. 7
Betweenness ......................................................................................................................... 8
Closeness ............................................................................................................................... 8
Eigenvector Centrality ........................................................................................................... 8
Reach ..................................................................................................................................... 9
Density .................................................................................................................................. 9
Centralization ........................................................................................................................ 9
Structural Cohesion ............................................................................................................. 10
Structural Equivalence ........................................................................................................ 10
Homophily ........................................................................................................................... 10
Clustering .................................................................................................................................... 10
Clustering Coefficient .......................................................................................................... 11
Clique .................................................................................................................................. 12
Power law distribution ............................................................................................................... 12

Small World Phenomenon .......................................................................................................... 12
Seasonality of Disease ................................................................................................................. 13
RFID Network .............................................................................................................................. 13
Methods .............................................................................................................................................. 13
Study Funding ............................................................................................................................. 13
Study Setting ............................................................................................................................... 14
Data Source ................................................................................................................................. 14
The FirstNet Emergency Department Triage and Tracking ................................................. 14
The Radiense Radiofrequency Identification (RFID) System ............................................... 14
Sampling Period .................................................................................................................. 14
Data Preparation ................................................................................................................. 15
Outcome Variables ...................................................................................................................... 15
Measures of Centrality ........................................................................................................ 15
Measures of Clustering ....................................................................................................... 15
Measures of Distance .......................................................................................................... 15
Independent Variables ................................................................................................................ 16
Quarter ................................................................................................................................ 16
Day of the Week .................................................................................................................. 16
Weekend/Weekday ............................................................................................................ 16
H1N1 Season ....................................................................................................................... 17
Shift (AM/PM) ..................................................................................................................... 17
Statistical Analysis ....................................................................................................................... 17
Software Packages ...................................................................................................................... 18
Results ................................................................................................................................................. 18
Introduction ................................................................................................................................ 18
Study Population ......................................................................................................................... 18
Outcome Variables ...................................................................................................................... 19
Degree ................................................................................................................................. 19
Shortest Path ....................................................................................................................... 22
Diameter ............................................................................................................................. 25
Density ................................................................................................................................ 28

Clustering Coefficient .......................................................................................................... 30
Discussion............................................................................................................................................ 33
Public Health Implications........................................................................................................... 33
Degree ................................................................................................................................. 33
Shortest Path ....................................................................................................................... 33
Distance ............................................................................................................................... 33
Density ................................................................................................................................ 33
Clustering Coefficient .......................................................................................................... 34
Future Directions ........................................................................................................................ 34
References .................................................................................................................................................. 35
Appendix A: All Tables................................................................................................................................. 38
Appendix B: SAS Program Code: ................................................................................................................ 83
Appendix C: Map of Emory University Midtown Hospital Emergency Department ................................ 106

About this Master's Thesis

Rights statement
  • Permission granted by the author to include this thesis or dissertation in this repository. All rights reserved by the author. Please contact the author for information regarding the reproduction and use of this thesis or dissertation.
School
Department
Subfield / Discipline
Degree
Submission
Language
  • English
Research field
Keyword
Committee Chair / Thesis Advisor
Committee Members
Partnering Agencies
Last modified

Primary PDF

Supplemental Files