Table 1:
ICD-10 Codes and Descriptions.
| I60.0 – I60.5 | Non-traumatic Subarachnoid haemorrhage from specified anatomical locations including carotid siphon and bifurcation, middle cerebral, anterior communicating, posterior communicating, basilar and vertebral arteries. |
| I60.6 | Subarachnoid haemorrhage from other intracranial arteries. |
| I60.7 | Subarachnoid haemorrhage from unspecified intracranial artery. |
| I60.8 | Other subarachnoid haemorrhage. |
| I60.9 | Subarachnoid haemorrhage, unspecified. |
Figure 1:
Flowchart describing the identification of aneurysmal subarachnoid haemorrhage cases from initial administrative data search using international classification of diseases-10 codes to final validation of cases.
Table 2:
Percentage of valid aneurysmal subarachnoid haemorrhage events using International Classification of diseases-10th edition coding by hospital admissions, with ICD coding available for 360 admissions representing 282 individual cases.
| Valid (%) | Not Valid (%) | P value | |
|---|---|---|---|
| Individual Admissions | |||
| Total, n= 282 | 172 (60.99) | 110 (39.01) | |
| Regional admission, n= 122 * | 85 (69.67) | 37 (30.33) | |
| Neurosurgical admission, n= 238 | 184 (77.31) | 54 (22.69) | 0.15 |
Table 3:
Validation coding utilising information gathered from discharge summaries.
| Sensitivity (95% CI) | Specificity (95% CI) | Positive Predictive Value (95% CI) | |
|---|---|---|---|
| Neurosurgical: I60.0–I60.8, n= 238 | 0.83 (0.76–0.88) | 0.70 (0.59–0.80) | 85.2% (78.7–90.4) |
| Combined: I60.0–I60.8, n= 360 | 0.71 (0.65–0.77) | 0.77 (0.69–0.84) | 83.2% (77.1–88.2) |
| Neurosurgical: I60.0–I60.9, n= 238 | 0.91 (0.86–0.95) | 0.27 (0.18–0.39) | 72.4% (65.7–78.4) |
| Combined: I60.0–I60.9, n= 360 | 0.90 (0.86–0.94) | 0.23 (0.16–0.31) | 65.1% (59.5–70.4) |
Table 4:
Validation coding utilising gold standard information gathered from individual medical records.
| Sensitivity (95% CI) | Specificity (95% CI) | Positive Predictive Value (95% CI) | |
|---|---|---|---|
| Neurosurgical: I60.0–I60.8, n= 238 | 0.82 (0.75–0.87) | 0.65 (0.54–0.76) | 82.1% (75.1–87.7) |
| Combined: I60.0–I60.8, n= 360 | 0.67 (0.60–0.73) | 0.72 (0.63–0.79) | 80.5% (74.2–85.9) |
| Neurosurgical: I60.0–I60.9, n= 238 | 0.91 (0.85–0.95) | 0.26 (0.17–0.37) | 70.4% (63.7–76.6) |
| Combined: I60.0–I60.9, n= 360 | 0.90 (0.86–0.94) | 0.24 (0.17–0.32) | 67.4% (61.9–72.6) |
| Population: I60.0–I60.8, n= 414 | 0.54 (0.48–0.60) | 0.72 (0.64–0.80) | 80.5% (74.2–85.9) |
| Population: I60.0–I60.9, n= 414 | 0.74 (0.68–0.79) | 0.25 (0.18–0.33) | 67.4% (61.9–72.6) |
Table 5:
Validation coding of specific haemorrhage location utilising gold standard information gathered from individual medical records.
| Sensitivity (95% CI) | Specificity (95% CI) | Positive Predictive Value (95% CI) | |
|---|---|---|---|
| Neurosurgical, n= 238 | 0.68 (0.59–0.75) | 0.90 (0.81–0.95) | 91.9% (85.2–96.2) |
| Combined, n= 360 | 0.52 (0.45–0.58) | 0.91 (0.85–0.95) | 90.5% (84.0–95.0) |