2014.ISDS.Abstracts.Final.pdf


ISDS Annual Conference Proceedings 2014. This is an Open Access article distributed under the terms of the Creative Commons Attribution-
Noncommercial 3.0 Unported License (http://creativecommons.org/licenses/by-nc/3.0/), permitting all non-commercial use, distribution, 
and reproduction in any medium, provided the original work is properly cited.

ISDS 2014 Conference Abstracts

A Comparison of Fever Classified Chief Complaints and 
Diagnoses with Recorded Body Temperatures

Patricia Araki*, Emily Kajita, Kelsey OYong, Monica Z. Luarca, Bessie Hwang and Laurene 
Mascola

County of Los Angeles, Department of Public Health, Los Angeles, CA, USA

Objective
The Los Angeles County (LAC) Emergency Department (ED) 

Syndromic Surveillance System (SSS) classifies patients into 
syndrome categories based on stated chief complaints. In an effort 
to evaluate the accuracy of patient- stated chief complaints and 
final diagnoses, both “fever” chief complaints and diagnoses were 
compared with patient body temperature readings.

Introduction
The LAC SSS has been in existence since 2004. Currently, the 

system collects data from over 50 hospitals daily and performs a chief 
complaint-based syndrome classification analysis of all ED visits. 
The keyword “fever” is of special interest due to its inclusion within 
several syndrome category definitions such as influenza, meningitis, 
etc. However, inclusion of such terms in syndrome definitions may 
be a disadvantage as such keyword searches would depend upon the 
consistency in which the term “fever” is reported. In 2014, several 
LAC syndromic surveillance hospital data connections were upgraded 
to include notes recording patient body temperature. To evaluate the 
newly added temperature information, analyses were conducted on 
those observations that included body temperature, chief complaint, 
and diagnosis information.

Methods
For this study, emergency department admitting data from 9 

hospitals were reviewed. A total of 24,402 observations from a 
five month period were categorized into groups by patient body 
temperature, those with fever classified chief complaints (n=1441) 
that included the terms “fever” or “febrile”, or patients with a similarly 
defined fever classified diagnosis (n=970) and/or corresponding ICD9 
code. Binary classification tests were conducted on this population 
to observe fever classified chief complaint and diagnosis outcomes 
against selected body temperature ranges.

Results
The sensitivities for fever classified chief complaints were 28.5%, 

59.8%, and 73.9% for body temperatures 99°F, 100°F, and 101°F, 
respectively. Corresponding positive predictive values (PPV) were 
60.7%, 43.2%, and 27.8% for the same groups. For fever classified 
diagnoses, sensitivities were found to be 22.2%, 47.5%, and 56.9% 
while PPVs were at 70.3%, 51.0%, and 31.8%, respectively, for 
the same temperature groups. The majority of fever classified chief 
complaints (81.4%) and diagnoses (75.7%) were categorized into 
the respiratory syndrome category with 54.3% of all fever classified 
chief complaints resulting in a consistent diagnosis. Furthermore, 
55% of observations with both a fever classified chief complaint and 
diagnosis also recorded body temperatures at or above 100°F.

Conclusions
These preliminary findings have provided a basic understanding of 

the utilization of the term “fever” within the LAC SSS. In addition, 
the evaluation of body temperature versus fever classified chief 
complaints and diagnoses will be utilized to determine whether, 

and how, the body temperature variable may be included in future 
iterations of syndrome classification algorithms.

Keywords
fever; syndromic surveillance; temperature; chief complaint

*Patricia Araki

E-mail: paraki@ph.lacounty.gov    

Online Journal of Public Health Informatics * ISSN 1947-2579 * http://ojphi.org * (1):e105, 201