I just finished writing a white paper for HIMSS titled "Defining and Testing EMR Usability: Principles and Proposed Methods of EMR Usability Evaluation and Rating". It's publicly available at this link.
It has been a great team to work with. Many thanks to my Human-Computer Interaction co-authors, Rebecca Grayson and Janey Barnes. They brought experience with clinical systems and their body of user-centered design knowledge to the task. Thanks also to the team leaders Penn White MD and Tiana Thomas for harnessing the power of a cadre of volunteer contributors to the effort.
Briefly, this paper describes how poor EMR usability has hindered user adoption among physicians and hospitals. We describe a number of usability principles that apply to EMRs in particular, and then offer evaluation and testing methods for finished EMR products, and suggest ways to rate the EMRs.
Our hope is that certifying and rating organizations such as Certification Commission for Healthcare Information Technology (CCHIT) or the American Academy of Family Physicians (AAFP) will be able to use this work in developing their own rating methods that can help EMR purchasers.