Where do the numbers come from?
The data is obtained from multiple sources, including the Armed Forces Health Surveillance Division (AFHSD), which operates the Defense Medical Surveillance System, a continuously expanding relational database that documents military and medical experiences of service members throughout their careers. Also, the Theater Medical Data Store, a web-based application used to track, analyze, and manage a service members’ medical treatment information recorded on the battlefield.
How are TBI cases defined?
A TBI case is defined based on the Department of Defense (DOD) Standard Surveillance Case Definition for TBI (under 14.0 Neurology) used by the AFHSB for routine surveillance and reporting.
The first inpatient or outpatient TBI medical encounter is identified using billing codes from insurance claims defined in the appropriate version of the International Classification of Diseases. The International Classification of Diseases, 10th edition, Clinical Modification (ICD-10-CM) took effect Oct. 1, 2015, replacing the ICD-9-CM coding guidelines. Military treatment facilities code medical encounters using ICD-10-CM and other DOD specific codes. TBICoE has curated a helpful ICD-10 Coding Guidance for TBI for providers.
If a service member has sustained more than one TBI, are all of them counted?
No. If a service member has had more than one TBI, only one of their injuries is counted for the purpose of this reporting.
If a service member has sustained more than one type of TBI, are both counted?
TBIs are classified as mild, moderate, severe, or penetrating. If a service member has sustained more than one type of TBI, the highest TBI severity is reported. For example, a service member with a previous ‘mild’ TBI will be counted as having a ‘moderate’ TBI if the individual is later diagnosed with a ‘moderate’ TBI. The date of their first TBI medical encounter determines the date on which they’re reported as a TBI surveillance case. This approach is intended to correct situations where new medical information is collected after the initial diagnosis and to avoid over counting the number of service members who have sustained a TBI.
How often are the numbers updated?
The numbers are updated both quarterly and annually. The numbers of service members diagnosed with a TBI for the current year and immediate past calendar year are updated quarterly. For all other years, the numbers are updated annually to reflect changes in the administrative databases.
What does a quarter cover?
The calendar year is divided into four quarters, often abbreviated Q1, Q2, Q3 and Q4. The four quarters that make up the year for the purposes of TBI surveillance reports are:
- Q1 represents the period January 1 – March 31
- Q2 represents the period April 1 – June 30
- Q3 represents the period July 1 – September 30
- Q4 represents the period October 1 – December 31
What other surveillance activities does TBICoE perform?
TBICoE performs more in-depth analysis on TBI-related data to include descriptions of risk and patterns of health care. Important public health findings are disseminated in medical journals. Health system management internal reports are provided to senior military leaders and may be available to military treatment facilities upon request. For public health purposes, TBICoE also collaborates with the Air Force Medical Readiness Decision Support Systems, Joint Trauma Analysis and Prevention of Injuries in Combat, Navy and Marine Corps Public Health Center, and Department of Veterans Affairs. For further information, please email the TBICoE surveillance team.