CAISS AIS Coding Principles 5 — Questions and Answers
Question 1: Which of the following best describes the purpose of the AIS pre-dot (descriptor) portion of the code?
- It identifies the year the AIS dictionary was published
- It provides a six-digit alphanumeric descriptor identifying the specific injury (Correct answer)
- It encodes the hospital trauma level designation
- It records the treating physician's specialty
Correct answer: It provides a six-digit alphanumeric descriptor identifying the specific injury
The pre-dot code is a six-digit numeric descriptor that uniquely identifies the injury type, structure, and region before the severity dot.
Question 2: When a patient presents with a closed head injury and epidural hematoma, which AIS code component differentiates this from a subdural hematoma?
- The body region digit
- The sixth digit (injury level/descriptor) (Correct answer)
- The severity score
- The NFS qualifier
Correct answer: The sixth digit (injury level/descriptor)
The specific anatomic descriptor digits in the pre-dot code distinguish epidural from subdural hematomas within the same head region.
Question 3: A fall victim has a fractured L2 vertebral body without neurological deficit. Under AIS, this is coded in which region?
- Region 4 — Abdomen
- Region 5 — Extremities
- Region 6 — Spine (Correct answer)
- Region 3 — Thorax
Correct answer: Region 6 — Spine
All vertebral fractures, with or without cord injury, are coded in AIS region 6 (Spine).
Question 4: Which principle governs how AIS coders handle injuries documented only by mechanism (e.g., 'hit by car') with no clinical findings in the record?
- Assign AIS 1 for all mechanism-only entries as a default
- Do not assign an AIS code — a diagnosis or clinical finding is required (Correct answer)
- Assign AIS 9 to all mechanism-documented cases
- Code the most likely injury based on mechanism statistics
Correct answer: Do not assign an AIS code — a diagnosis or clinical finding is required
AIS coding requires a documented injury diagnosis or clinical finding; mechanism alone without a confirmed injury cannot be coded.
Question 5: What is the maximum possible ISS score, and how is it achieved?
- 72, by having AIS 6 in two body regions
- 75, by having AIS 5 in three different body regions
- 75, by having AIS 6 in any body region (Correct answer)
- 75, by having AIS 5 in all six body regions
Correct answer: 75, by having AIS 6 in any body region
A single AIS 6 injury in any body region automatically results in an ISS of 75 (the maximum), regardless of other injuries.
Question 6: An open femur fracture with vascular injury would be coded differently from a closed femur fracture primarily because:
- Open fractures always receive AIS 6
- Vascular involvement and wound type change the specific descriptor code and may elevate severity (Correct answer)
- Closed fractures are not coded under AIS
- The body region assignment changes from 5 to 4
Correct answer: Vascular involvement and wound type change the specific descriptor code and may elevate severity
The presence of an open wound and vascular injury alters the AIS descriptor code and typically increases the severity score compared to a simple closed fracture.
Question 7: In AIS coding, the term 'definitive diagnosis' refers to which of the following documentation sources?
- Emergency physician's initial assessment only
- The most precise and final injury diagnosis supported by clinical, imaging, or surgical evidence (Correct answer)
- The discharge summary diagnosis exclusively
- The paramedic's field assessment
Correct answer: The most precise and final injury diagnosis supported by clinical, imaging, or surgical evidence
Definitive diagnosis in AIS is the most accurate final injury characterization derived from all available clinical data, including imaging and operative reports.
CAISS AIS Coding Principles 5
Which of the following best describes the purpose of the AIS pre-dot (descriptor) portion of the code?