Are patients with AIS code 9 injuries included in research studies?

Patients with AIS code 9 injuries, which are classified as "not applicable" or "unknown" in the Abbreviated Injury Scale classification, are typically not included in research studies. This exclusion is primarily due to the incomplete or inadequate information regarding these injuries, preventing researchers from accurately assessing outcomes, risks, or establishing relationships with variables. Studies often require clear and specific data to draw reliable conclusions, and code 9 does not provide that necessary detail.

Including patients with AIS code 9 would complicate the analysis and might skew results, making it difficult to derive meaningful insights about certain injury types or treatment effectiveness. As a result, research protocols generally aim for clarity and precision when defining participant criteria, leading to the decision to exclude such patients from studies. In many cases, research ethics and integrity demand a sound basis for inclusion, which code 9 fails to provide.