EMR Usability

I've written before about EMR usability.  It's the missing feature in many EMR evaluations.  They all have bullet points:

• Prescription Writing
• Problem Lists
• Medication Lists
• Allergy Checking
• Scanning support

And so on ... but

• Is easy to use

Isn't necessarily on anyone's list .. and even if it is .. this is hard to measure.  While usability is subjective .. there should be simple ways for us to define usability.  How many mouse clicks does it take to accomplish a task?  How long does it take to do something?  Vendors brag about ease of use ... but it depends on the context, the user's skill level, the hardware that the product is used on .. etc etc etc