Table 2 describes the main types of TBI identifiable in the NIHSI AA dataset.
|ICD-10-AM diagnosis||ICD-10-AM code||Condition description||Primary diagnosis – Concussion||Primary diagnosis – Traumatic subarachnoid haemorrhage||Primary diagnosis – Traumatic subdural haemorrhage||Primary diagnosis – Other TBI||Additional diagnosis – Concussion||Additional diagnosis – Non-concussive TBI|
|Concussive injury||S06.0||Brain injury caused by a blow to the head or violent shaking of the head. May be with or without loss of consciousness|
|Traumatic subdural haemorrhage||S06.5||Blood collects between the covering of the brain and the surface of the brain|
|Traumatic subarachnoid haemorrhage||S06.6||Bleeding between the arachnoid (the middle membrane surrounding the brain) and pia mater (the inner membrane surrounding the brain)|
|Traumatic cerebral oedema||S06.1
||Swelling of the brain|
|Diffuse brain injury||S06.02||Wide area of brain tissue is affected|
|Focal brain injury||S06.03||Localised or limited brain tissue affected|
|Epidural haemorrhage||S06.04||Bleeding between the inside of the skull and the dura mater (the outer membrane surrounding the brain)|
|Other intracranial injuries||S06.08||Other intracranial injuries such as traumatic haemorrhage, haematoma or contusion|
Note that the ‘Principal diagnosis – Other TBIs’ and ‘Additional diagnosis – Non-concussive TBIs’ categories comprise different sets of conditions. This is because within the TBI as a principal diagnosis set, traumatic subarachnoid haemorrhage and traumatic subdural haemorrhage are reported separately, while within the TBI as additional diagnosis data, they are included in the ‘Additional diagnosis – Non-concussive TBI’ category, because the number of cases was very low.
For over 14,500 people (62%) in the cohort, the TBI was the principal diagnosis, meaning TBI was the main reason they were admitted to hospital (Figure 3; Table S1). The remainder of the cohort (38%) had TBI recorded as an additional diagnosis, alongside a different principal diagnosis that was the chief reason for hospital admission.
Concussion, with or without loss of consciousness, was the most common type of TBI diagnosis, representing 74% (17,250 cases) of initial TBI admissions.
Figure 3: Number of cohort patients by TBI diagnosis
Source: AIHW NIHSI AA v0.5.