Ostermayer: Create Ottawa SAH Calculator template (modeled on Canadian CT Head Calculator pattern; 6 binary criteria from Perry 2013)

2026-04-28T04:30:55Z

Create Ottawa SAH Calculator template (modeled on Canadian CT Head Calculator pattern; 6 binary criteria from Perry 2013)

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<noinclude>Interactive Ottawa SAH (Subarachnoid Hemorrhage) Rule calculator. Requires the [[MediaWiki:Gadget-calculator.js|calculator gadget]]. Usage: <code><nowiki>{{Ottawa SAH Calculator}}</nowiki></code>

[[Category:Calculator templates]]</noinclude>
=== Ottawa SAH Rule ===
<div class="calculator-container" data-calculator-refresh-on-load="true">
{| class="wikitable" style="width:100%; border-collapse:collapse;"
|+ style="font-size:16px; font-weight:bold; padding:8px; background:#922b21; color:white;" | Ottawa SAH Rule — [[Aneurysmal subarachnoid hemorrhage|SAH]] Risk in Acute Headache
|-
! colspan="3" style="background:#fadbd8;" | Inclusion: alert patients >15 years old with new severe non-traumatic headache reaching maximum intensity within 1 hour. ''Not'' for patients with new neurologic deficits, prior aneurysm/SAH, known brain tumor, or chronic recurrent headaches (≥3 episodes over ≥6 months).
|-
! style="width:60%; background:#fadbd8;" | Criterion
! style="width:20%; background:#fadbd8;" | No
! style="width:20%; background:#fadbd8;" | Yes
|-
| '''Age ≥40 years'''
| {{calculator|id=osah_ageNo|type=radio|name=osah_age|default=1}}
| {{calculator|id=osah_ageYes|type=radio|name=osah_age}}
|-
| '''Neck pain or stiffness'''
| {{calculator|id=osah_neckNo|type=radio|name=osah_neck|default=1}}
| {{calculator|id=osah_neckYes|type=radio|name=osah_neck}}
|-
| '''Witnessed loss of consciousness'''
| {{calculator|id=osah_locNo|type=radio|name=osah_loc|default=1}}
| {{calculator|id=osah_locYes|type=radio|name=osah_loc}}
|-
| '''Onset during exertion'''
| {{calculator|id=osah_exNo|type=radio|name=osah_ex|default=1}}
| {{calculator|id=osah_exYes|type=radio|name=osah_ex}}
|-
| '''Thunderclap headache''' (instantaneous peak intensity)
| {{calculator|id=osah_tcNo|type=radio|name=osah_tc|default=1}}
| {{calculator|id=osah_tcYes|type=radio|name=osah_tc}}
|-
| '''Limited neck flexion on exam'''
| {{calculator|id=osah_flexNo|type=radio|name=osah_flex|default=1}}
| {{calculator|id=osah_flexYes|type=radio|name=osah_flex}}
|-
! style="background:#922b21; color:white;" | Criteria Present
! colspan="2" style="background:#922b21; color:white; font-size:18px;" | {{calculator|id=osah_total|type=plain|formula=osah_ageYes+osah_neckYes+osah_locYes+osah_exYes+osah_tcYes+osah_flexYes|style=min-width:3ch;display:inline-block}} / 6
|}

{| class="wikitable" style="width:100%; margin-top:4px;"
! colspan="2" | Interpretation
|-
| style="background:#27ae60; color:white; text-align:center; width:25%; font-weight:bold;" | 0 of 6
| '''SAH effectively ruled out''' — 100% sensitivity in validation study. Further investigation for SAH not required based on this rule alone; consider alternative headache etiologies.
|-
| style="background:#e74c3c; color:white; text-align:center; font-weight:bold;" | ≥1 of 6
| '''SAH NOT ruled out''' — rule does not rule in SAH; proceed with non-contrast [[Head CT|CT head]] (within 6 hours of onset is most sensitive) ± [[lumbar puncture]] if CT negative and clinical suspicion remains.
|}

{| class="wikitable" style="width:100%; margin-top:4px; font-size:90%;"
! References
|-
|
* Perry JJ, Stiell IG, Sivilotti MLA, et al. Clinical decision rules to rule out subarachnoid hemorrhage for acute headache. ''JAMA.'' 2013;310(12):1248-1255. PMID 24065011.
* Perry JJ, Sivilotti MLA, Sutherland J, et al. Validation of the Ottawa Subarachnoid Hemorrhage Rule in patients with acute headache. ''CMAJ.'' 2017;189(45):E1379-E1385. PMID 29133539.
* '''Sensitivity:''' 100% (95% CI 94.6–100); '''Specificity:''' ~13–15% — high sensitivity tool intended to identify patients who do NOT need further SAH workup.
|}
</div>

Template:Ottawa SAH Calculator - Revision history

Ostermayer: Create Ottawa SAH Calculator template (modeled on Canadian CT Head Calculator pattern; 6 binary criteria from Perry 2013)