Journal Club Summary

Methodology Score: 4.5/5                         
Usefulness Score: 4/5
Perry JJ, Stiell IG, Sivilotti ML, Bullard MJ, Hohl CM, Sutherland J, Émond M, Worster A, Lee JS, Mackey D, Pauls M, Lesiuk H, Symington C, Wells GA.
JAMA. 2013;310(12):1248-1255.
This multicentre prospective validation cohort study found that the 3 previously created subarachnoid hemorrhage (SAH) decision rules had very good sensitivity (>90%) and by refinement of these rules, the Ottawa SAH rule was derived which was shown to rule out SAH with a sensitivity of 100% (95%CI 97.2-100%). The group agreed that this rule is easy to apply, this study had sound methodology, and although the rule would not change imaging rates, it could decrease the SAH miss rate.  We are eagerly awaiting the prospective validation and implementation study results so we can use it in practice. 
By: Dr. Kate McCubbin
(Presented November 2013)

Epi lesson: Phases of Clinical Decision Rule Development 

Rigorous clinical decision rules undergo 3 key phases of development: 1) derivation where clinically important predictor variables are identified; 2) validation where the rule is prospectively applied in a similar clinical setting as in the derivation phase; 3) implementation where the rule is evaluated for impact on physician behaviour, patient outcomes and sometimes cost. 
By: Dr. Lisa Calder