Something to keep in mind about decision rules:
They are invented to help you when there's a gap in your clinical judgement. But, none apply to all patient populations (the studies usually exclude certain categories of patients, which for all you know, your patient could be in). Also, none are 100% accurate. Most importantly, all have (or a t least should have) a disclaimer saying something like this, "Clinical decision rules are not intended to take the place of clinical judgment." Make a point to search the text of these decision rules for these "don't rely on me" disclaimers. You might have to go to the original journal text.
So what good is a rule to help us when there's a gap in my clinical judgement, if the rule ultimately relies on my clinical judgement?
I think they're a good learning tool. And they're a good way (sometimes) to work through a difficult case, to give one confidence, if the rule agrees with your pre-decision rule assessment. But ultimately, it's up to us to know how and when to apply these rules, and it's up to us to know when the rule is wrong. And if you're relying on the rule to be smarter than you, you're falling into a trap. It's not like a diagnostic study with another physician's name, judgement and license attached to it, like a radiologic study, or heart cath.
Can you blame the MD who's lead author on the paper that invented the decision rule, if it turns out to be wrong?
Can you or the patient sue those who developed the decision rule, if it turns out your patient was in the excluded patient types and you miss something?
No.
Decision rules can be good learning tools.
They do not replace clinical judgement.
Ultimately, it's all you.