You are right in that the age wouldn't necessarily correlate with quality, but I can speak from first hand knowledge about the inertia that different EMRs bring

You are right in that the age wouldn't necessarily correlate with quality, but I can speak from first hand knowledge about the inertia that different EMRs bring. A lot of these drug interactions are mild precautions or the evidence changes with time. Ideally what is supposed to happen is a multidisciplinary committee reviews the latest evidence and continuously updates the interactions. What often happens though is that there isn't enough 'oomph' to override a previously established notification so inertia wins. It's often not until a major EMR upgrade where things get more closely looked at and some of the less important flags/notifications get weeded out out. Definitely true that new major interactions get added all the time and usually in a timely fashion. As you can also imagine there is a medico-legal aspect of removing a previous flag, so often it's easier to just leave it and make the provider do an extra unneeded click.