1. NHTSA’S Experience with the Crash Outcome Data Evaluation System
John Kindelberger
National Center for Statistics and Analysis,
National Highway Traffic Safety Administration
This is a U.S. Government work and may be copied and distributed without permission.

2. CODES Background
Since 1992, NHTSA’s Crash Outcome Data Evaluation System or CODES cultivated State-level data linkage through cooperative agreements with organizations that applied and qualified for their State.
Crash report data to medical (Inpatient, ED, EMS)
Allows analysis of injuries in crashes (ICD-9 CM, MAIS, ISS etc)
Other added data sets (registration, DMV, death, etc)
Linkage in different States is challenging
each State has different crash report forms, data systems, variables etc.
CODES software employs probabilistic linkage and multiple imputation
to conduct linkage even without perfect matches.

3. CODES Background
CODES always had a stated goal of institutionalization of CODES in the State.
In 2009, NHTSA shared a strategic plan aiming for eventual self-sufficiency of CODES in States.
In 2013, NHTSA completed final transition of CODES responsibility to States that opted to continue CODES.
During this time the US Centers for Disease Control (CDC) partnered with NHTSA to learn more about CODES.

4. CODES Background
NHTSA still believes in data linkage as an important component of data enhancement, and encourages States to conduct linkage programs.
In 2015, NHTSA published three final CODES reports (one with CDC)
summarizing CODES and what we learned
with the intent of preserving knowledge and helping future linkage projects.

5. Program Transition & Promising Practices
CODES Final Reports
Report 1:
CODES:
Program Transition & Promising Practices
John Kindelberger, NHTSA
Jacqueline Milani, University of Maryland
Contributions from CODES Grantees as
acknowledged in the paper

6. Example,
State
Promising Practice
Data Application Abstract

7. CODES: Examination of Methodologies
CODES Final Reports
Report 2:
CODES: Examination of Methodologies
& Multi-State Traffic Safety Applications
Lawrence J. Cook, Andrea Thomas,
Cody Olson, Tomohiko Funai, Timothy Simmons
University of Utah
Intermountain Injury Control Research Center
Partially funded by the CDC.

8. CODES: Examination of Methodologies & Multi-State Traffic Safety Applications
Part 1
CODES probabilistic linkage methodology; overview of other linkage software
Alternative types of linked data sets
Analysis of match probabilities, linking variables
Multiple imputation of missing data
Part 2: Four topic analyses using combined CODES data

9. Assessment of Characteristics of State Data Linkage Systems
CODES Final Reports
Report 3:
NHTSA/CDC Report
Assessment of Characteristics of
State Data Linkage Systems
Jacqueline Milani, University of Maryland
John Kindelberger, NHTSA
Gwendolyn Bergen, CDC
Emily Novicki, CDC
Cynthia Burch, University of Maryland
Shiu Ho, University of Maryland
Bethany West, CDC
Funded by the CDC.

10. Assessment of Characteristics of State Data Linkage Systems
Survey of CODES and non-CODES State linkage programs
Focus groups
Assess the facilitators and barriers to successful data linkage programs at State level

11. CODES Final Reports
The three final reports are available at NHTSA’s web site:

12. Current Events in Linkage
A number of CODES States continue linkage in self-sufficient programs.
Some non-CODES States have set up linkage projects or are planning to.
In Sept CDC published a Mortality and Morbidity Weekly Report using CODES data to examine child occupant protection.
NCHRP* project 17-57, Development of a Comprehensive Approach for Serious Traffic Crash Injury Measurement and Reporting Systems, UMTRI**report forthcoming
Report already available in conjunction with above :
NCHRP 20-24(37)K, Measuring Performance Among State DOTs: Sharing Good Practices – Serious Crash Injury (Cambridge Systematics, Inc.)
Linkage has a continued presence at ATSIP’s Traffic Records Forum
Data linkage round table, 2016 forum
* National Cooperative Highway Research Program ** University of Michigan Transportation Research Institute

13. Thank You For further information john. kindelberger@dot. gov www
Thank You For further information
This is a U.S. Government work and may be copied and distributed without permission.